diff --git a/code/def_files/data/effects/batched-f.sdr b/code/def_files/data/effects/batched-f.sdr
index 660787fe4e2..e46e5208afc 100644
--- a/code/def_files/data/effects/batched-f.sdr
+++ b/code/def_files/data/effects/batched-f.sdr
@@ -1,12 +1,16 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2DArray;
+#endif
 
 #include "gamma.sdr"
 
+layout(location=0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout (location = 0) in vec4 fragTexCoord;
 layout (location = 1) in vec4 fragColor;
 
-layout (location = 0) out vec4 fragOut0;
-
 layout (set = 1, binding = 1) uniform sampler2DArray baseMap;
 
 layout (set = 2, binding = 0, std140) uniform genericData {
@@ -17,8 +21,6 @@ layout (set = 2, binding = 0, std140) uniform genericData {
 in vec4 fragTexCoord;
 in vec4 fragColor;
 
-out vec4 fragOut0;
-
 uniform sampler2DArray baseMap;
 
 layout (std140) uniform genericData {
diff --git a/code/def_files/data/effects/batched-v.sdr b/code/def_files/data/effects/batched-v.sdr
index 9f1efb6f213..87bb3983acf 100644
--- a/code/def_files/data/effects/batched-v.sdr
+++ b/code/def_files/data/effects/batched-v.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+#endif
+
 #ifdef VULKAN
 layout (location = 0) in vec4 vertPosition;
 layout (location = 1) in vec4 vertColor;
diff --git a/code/def_files/data/effects/bloom-comp-f.sdr b/code/def_files/data/effects/bloom-comp-f.sdr
index 20d8859a643..74fee1c1c13 100644
--- a/code/def_files/data/effects/bloom-comp-f.sdr
+++ b/code/def_files/data/effects/bloom-comp-f.sdr
@@ -1,11 +1,16 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
+
+layout(location=0) out vec4 fragOut0;
 
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform sampler2D bloomed;
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
+
 uniform sampler2D bloomed;
 #endif
 
diff --git a/code/def_files/data/effects/blur-f.sdr b/code/def_files/data/effects/blur-f.sdr
index 8063b8e4e03..47bcf42da05 100644
--- a/code/def_files/data/effects/blur-f.sdr
+++ b/code/def_files/data/effects/blur-f.sdr
@@ -1,9 +1,15 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2D;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform sampler2D tex;
 #else
-out vec4 fragOut0;
 in vec4 fragTexCoord;
 uniform sampler2D tex;
 #endif
diff --git a/code/def_files/data/effects/brightpass-f.sdr b/code/def_files/data/effects/brightpass-f.sdr
index e1632a23d13..219f65bd06e 100644
--- a/code/def_files/data/effects/brightpass-f.sdr
+++ b/code/def_files/data/effects/brightpass-f.sdr
@@ -1,12 +1,18 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform sampler2D tex;
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
 uniform sampler2D tex;
 #endif
+
 const float Luminance = 0.08;
 const float fMiddleGray = 0.2;
 const float fWhiteCutoff = 0.4;
diff --git a/code/def_files/data/effects/copy-f.sdr b/code/def_files/data/effects/copy-f.sdr
index 28c29bdfac8..db9e9166b69 100644
--- a/code/def_files/data/effects/copy-f.sdr
+++ b/code/def_files/data/effects/copy-f.sdr
@@ -1,10 +1,15 @@
+#ifdef GL_ES
+precision highp sampler2D;
+precision highp sampler2DArray;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform sampler2D tex;
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
 #ifdef COPY_ARRAY
 uniform sampler2DArray tex;
 #else
diff --git a/code/def_files/data/effects/decal-f.sdr b/code/def_files/data/effects/decal-f.sdr
index 34d65a67ba8..6c1577bcd3d 100644
--- a/code/def_files/data/effects/decal-f.sdr
+++ b/code/def_files/data/effects/decal-f.sdr
@@ -1,3 +1,9 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2D;
+precision highp sampler2DArray;
+#endif
 
 // NOTE: The technique and some of this code is based on this tutorial:
 // http://martindevans.me/game-development/2015/02/27/Drawing-Stuff-On-Other-Stuff-With-Deferred-Screenspace-Decals/
@@ -29,9 +35,14 @@ layout (set = 1, binding = 1) uniform sampler2DArray decalTextures;
 layout (set = 1, binding = 4) uniform sampler2D gDepthBuffer;
 layout (set = 1, binding = 6) uniform sampler2D gNormalBuffer;
 #else
-out vec4 fragOut0; // Diffuse buffer
-out vec4 fragOut1; // Normal buffer
-out vec4 fragOut2; // Emissive buffer
+layout (location=0) out vec4 fragOut0; // Diffuse buffer
+#ifndef GL_ES
+layout (location=1) out vec4 fragOut1; // Normal buffer
+layout (location=2) out vec4 fragOut2; // Emissive buffer
+#else
+layout (location=2) out vec4 fragOut1; // Normal buffer   -> COLOR_ATTACHMENT2
+layout (location=4) out vec4 fragOut2; // Emissive buffer -> COLOR_ATTACHMENT4
+#endif
 
 flat in mat4 invModelMatrix;
 flat in vec3 decalDirection;
@@ -124,7 +135,7 @@ vec3 getPixelNormal(vec3 frag_position, vec2 tex_coord, inout float alpha, out v
 	}
 
 	// Make a smooth alpha transition leading up to an edge
-	alpha = alpha * (1 - smoothstep(angle_fade_start, normal_angle_cutoff, angle));
+	alpha = alpha * (1.0 - smoothstep(angle_fade_start, normal_angle_cutoff, angle));
 
 	return normal;
 }
diff --git a/code/def_files/data/effects/decal-v.sdr b/code/def_files/data/effects/decal-v.sdr
index 42d99146327..46998b7983a 100644
--- a/code/def_files/data/effects/decal-v.sdr
+++ b/code/def_files/data/effects/decal-v.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+#endif
 
 #ifdef VULKAN
 // Binding 0: box vertex positions
diff --git a/code/def_files/data/effects/default-material-f.sdr b/code/def_files/data/effects/default-material-f.sdr
index cec7df3a766..236421b31d7 100644
--- a/code/def_files/data/effects/default-material-f.sdr
+++ b/code/def_files/data/effects/default-material-f.sdr
@@ -1,3 +1,16 @@
+#ifdef GL_ES
+#extension GL_EXT_clip_cull_distance : enable
+precision highp float;
+precision highp int;
+precision highp sampler2DArray;
+#endif
+
+#if defined(VULKAN)
+//define USE_HW_CLIP_DISTANCE from engine side
+#elif !defined(GL_ES) || defined(GL_EXT_clip_cull_distance)
+	#define USE_HW_CLIP_DISTANCE
+#endif
+
 #ifdef VULKAN
 layout(set = 2, binding = 0, std140)
 #else
@@ -20,22 +33,28 @@ uniform genericData {
 	uint clipEnabled;
 };
 
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 
 layout(set = 1, binding = 1) uniform sampler2DArray baseMap;
 
 layout(location = 0) in vec4 fragTexCoord;
 layout(location = 1) in vec4 fragColor;
-
-layout(location = 0) out vec4 fragOut0;
+#ifndef USE_HW_CLIP_DISTANCE
+layout(location = 2) in float vClipDist;
+#endif
 
 #else
 
+#ifndef USE_HW_CLIP_DISTANCE
+in float vClipDist;
+#endif
+
 uniform sampler2DArray baseMap;
 
 in vec4 fragTexCoord;
 in vec4 fragColor;
-out vec4 fragOut0;
 
 #endif
 
@@ -43,6 +62,11 @@ out vec4 fragOut0;
 
 void main()
 {
+#ifndef USE_HW_CLIP_DISTANCE
+	if (clipEnabled != 0u && vClipDist < 0.0) {
+		discard;
+	}
+#endif
 	vec4 baseColor = texture(baseMap, vec3(fragTexCoord.xy, float(baseMapIndex)));
 	if(alphaThreshold > baseColor.a) discard;
 	baseColor.rgb = (srgb == 1) ? srgb_to_linear(baseColor.rgb) : baseColor.rgb;
diff --git a/code/def_files/data/effects/default-material-v.sdr b/code/def_files/data/effects/default-material-v.sdr
index 902240860ea..07e1fb2ddc4 100644
--- a/code/def_files/data/effects/default-material-v.sdr
+++ b/code/def_files/data/effects/default-material-v.sdr
@@ -1,3 +1,15 @@
+#ifdef GL_ES
+#extension GL_EXT_clip_cull_distance : enable
+precision highp float;
+precision highp int;
+#endif
+
+#if defined(VULKAN)
+//define USE_HW_CLIP_DISTANCE from engine side
+#elif !defined(GL_ES) || defined(GL_EXT_clip_cull_distance)
+	#define USE_HW_CLIP_DISTANCE
+#endif
+
 #ifdef VULKAN
 layout(set = 2, binding = 0, std140)
 #else
@@ -38,10 +50,15 @@ layout(location = 2) in vec4 vertTexCoord;
 
 layout(location = 0) out vec4 fragTexCoord;
 layout(location = 1) out vec4 fragColor;
+#ifndef USE_HW_CLIP_DISTANCE
+layout(location = 2) out float vClipDist;
+#endif
 
 #else
 
-out float gl_ClipDistance[1];
+#ifndef USE_HW_CLIP_DISTANCE
+out float vClipDist;
+#endif
 
 out vec4 fragTexCoord;
 in vec4 vertTexCoord;
@@ -58,13 +75,16 @@ void main()
 	gl_Position = projMatrix * modelViewMatrix * vertPosition;
 
 	if (clipEnabled != 0u) {
+		#ifdef USE_HW_CLIP_DISTANCE
 		gl_ClipDistance[0] = dot(clipEquation, modelMatrix * vertPosition);
+		#else
+		vClipDist = dot(clipEquation, modelMatrix * vertPosition);
+		#endif
 	} else {
-#ifdef VULKAN
-		// Vulkan has no glEnable(GL_CLIP_DISTANCE0) equivalent — clip distances are
-		// always evaluated when declared in the shader.  Must write a positive value
-		// when clipping is disabled to prevent undefined-value vertex culling.
+		#ifdef USE_HW_CLIP_DISTANCE
 		gl_ClipDistance[0] = 1.0;
-#endif
+		#else
+		vClipDist = 1.0;
+		#endif
 	}
 }
diff --git a/code/def_files/data/effects/deferred-clear-f.sdr b/code/def_files/data/effects/deferred-clear-f.sdr
index 4d49695ef90..3faddb831fe 100644
--- a/code/def_files/data/effects/deferred-clear-f.sdr
+++ b/code/def_files/data/effects/deferred-clear-f.sdr
@@ -1,9 +1,14 @@
-out vec4 fragOut0;
-out vec4 fragOut1;
-out vec4 fragOut2;
-out vec4 fragOut3;
-out vec4 fragOut4;
-out vec4 fragOut5;
+#ifdef GL_ES
+precision highp float;
+#endif
+
+layout (location=0) out vec4 fragOut0;
+layout (location=1) out vec4 fragOut1;
+layout (location=2) out vec4 fragOut2;
+layout (location=3) out vec4 fragOut3;
+layout (location=4) out vec4 fragOut4;
+layout (location=5) out vec4 fragOut5;
+
 void main()
 {
 	fragOut0 = vec4(0.0, 0.0, 0.0, 1.0); // color
diff --git a/code/def_files/data/effects/deferred-f.sdr b/code/def_files/data/effects/deferred-f.sdr
index fb5d9021ebd..d27e86ffc05 100644
--- a/code/def_files/data/effects/deferred-f.sdr
+++ b/code/def_files/data/effects/deferred-f.sdr
@@ -1,13 +1,21 @@
 //? #version 150
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2D;
+precision highp samplerCube;
+precision highp sampler2DArrayShadow;
+#endif
+
 #include "lighting.sdr" //! #include "lighting.sdr"
 #include "gamma.sdr" //! #include "gamma.sdr"
 #include "shadows.sdr" //! #include "shadows.sdr"
 #include "z-compress.sdr" //! #include "z-compress.sdr"
 
-#ifdef VULKAN
+#ifndef GL_ES
 layout(location = 0) out vec4 fragOut0;
 #else
-out vec4 fragOut0;
+layout(location = 5) out vec4 fragOut0; //COLOR_ATTACHMENTn is on location n in ES, here it uses COLOR_ATTACHMENT5
 #endif
 
 #ifdef VULKAN
@@ -141,7 +149,7 @@ void GetLightInfo(vec3 position, in float alpha, in vec3 reflectDir, out vec3 li
 			dist = length(lightDirOut);
 			lightDist = dist;
 			// Energy conservation term
-			float alpha_adjust = clamp(alpha + (sourceRadius/(2*dist)), 0.0, 1.0);
+			float alpha_adjust = clamp(alpha + (sourceRadius/(2.0*dist)), 0.0, 1.0);
 			area_normalisation = alpha/alpha_adjust;
 			area_normalisation *= area_normalisation;
 			//end chunk
@@ -184,7 +192,7 @@ void GetLightInfo(vec3 position, in float alpha, in vec3 reflectDir, out vec3 li
 			float dist = length(lightDirOut);
 			lightDist = dist;
 			// Energy conservation term
-			float alpha_adjust = min(alpha + (sourceRadius/(2*dist)), 1.0);
+			float alpha_adjust = min(alpha + (sourceRadius/(2.0*dist)), 1.0);
 			area_normalisation = alpha/alpha_adjust;
 			// don't need to square as it's a line rather than a sphere.
 			//end chunk
@@ -231,11 +239,11 @@ void ComputeEnvLight(float alpha, float ao, vec3 light_dir, vec3 eyeDir, vec3 no
 	// so let s = (2/alpha^2 - 2)
 	// 1/2 log(s + 1) = 1/2 log(2/alpha^2 -1)
 
-	const float ENV_REZ = 512; // Ideally this would be #define'd and shader recompiled with envmap rez changes
-	const float REZ_BIAS = log2(ENV_REZ * sqrt(3));
+	const float ENV_REZ = 512.0; // Ideally this would be #define'd and shader recompiled with envmap rez changes
+	const float REZ_BIAS = log2(ENV_REZ * sqrt(3.0));
 
 	float alphaSqr = alpha * alpha;
-	float rough_bias = 0.5 * log2(2/alphaSqr - 1);
+	float rough_bias = 0.5 * log2(2.0/alphaSqr - 1.0);
 	float mip_bias = REZ_BIAS - rough_bias;
 
 	// Sample light, using mip bias to blur it.
@@ -253,7 +261,7 @@ void ComputeEnvLight(float alpha, float ao, vec3 light_dir, vec3 eyeDir, vec3 no
 	// Pseudo-IBL, so use k_IBL
 	float k = alpha * alpha/ 2.0f;
 
-	float NdotL = max(dot(light_dir, normal),0);
+	float NdotL = max(dot(light_dir, normal),0.0);
 
 	float g1vNL = GeometrySchlickGGX(NdotL, k);
 	vec3 specEnvLighting = specEnvColour.rgb * fresnel * g1vNL;
@@ -331,6 +339,6 @@ void main()
 		float NdotL = clamp(dot(normal, lightDir), 0.0, 1.0);
 		fragmentColor.rgb = computeLighting(specColor.rgb, diffColor, lightDir, normal.xyz, halfVec, eyeDir, roughness, fresnel, NdotL).rgb * diffuseLightColor * attenuation * area_normalisation;
 	}
-
+	
 	fragOut0 = max(fragmentColor, vec4(0.0));
 }
diff --git a/code/def_files/data/effects/deferred-v.sdr b/code/def_files/data/effects/deferred-v.sdr
index 2c9d4b02c66..98fa87d7f67 100644
--- a/code/def_files/data/effects/deferred-v.sdr
+++ b/code/def_files/data/effects/deferred-v.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+#endif
 
 #include "lighting.sdr"
 
diff --git a/code/def_files/data/effects/effect-distort-f.sdr b/code/def_files/data/effects/effect-distort-f.sdr
index b43907a39da..d06ff7409d8 100644
--- a/code/def_files/data/effects/effect-distort-f.sdr
+++ b/code/def_files/data/effects/effect-distort-f.sdr
@@ -1,10 +1,16 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+precision highp sampler2DArray;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec4 fragTexCoord;
 layout(location = 1) in vec4 fragColor;
 layout(location = 2) in float fragOffset;
 
-layout(location = 0) out vec4 fragOut0;
-
 layout(set = 1, binding = 1) uniform sampler2DArray baseMap;
 layout(set = 1, binding = 4) uniform sampler2D depthMap;
 layout(set = 1, binding = 5) uniform sampler2D frameBuffer;
@@ -14,8 +20,6 @@ in vec4 fragTexCoord;
 in vec4 fragColor;
 in float fragOffset;
 
-out vec4 fragOut0;
-
 uniform sampler2DArray baseMap;
 uniform sampler2D depthMap;
 uniform sampler2D distMap;
diff --git a/code/def_files/data/effects/effect-distort-v.sdr b/code/def_files/data/effects/effect-distort-v.sdr
index 5673b1baf3e..2eb075be1d4 100644
--- a/code/def_files/data/effects/effect-distort-v.sdr
+++ b/code/def_files/data/effects/effect-distort-v.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+#endif
+
 #ifdef VULKAN
 layout(location = 0) in vec4 vertPosition;
 layout(location = 1) in vec4 vertColor;
diff --git a/code/def_files/data/effects/effect-f.sdr b/code/def_files/data/effects/effect-f.sdr
index f46147830e5..b8a73fbef8d 100644
--- a/code/def_files/data/effects/effect-f.sdr
+++ b/code/def_files/data/effects/effect-f.sdr
@@ -1,15 +1,21 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2D;
+precision highp sampler2DArray;
+#endif
 
 #include "gamma.sdr"
 #include "z-compress.sdr"
 
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec4 fragTexCoord;
 layout(location = 1) in vec4 fragColor;
 layout(location = 2) in float fragRadius;
 layout(location = 3) in vec4 fragPosition;
 
-layout(location = 0) out vec4 fragOut0;
-
 layout(set = 1, binding = 1) uniform sampler2DArray baseMap;
 layout(set = 1, binding = 4) uniform sampler2D depthMap;
 #else
@@ -18,8 +24,6 @@ in vec4 fragPosition;
 in vec4 fragTexCoord;
 in vec4 fragColor;
 
-out vec4 fragOut0;
-
 uniform sampler2DArray baseMap;
 uniform sampler2D depthMap;
 #endif
diff --git a/code/def_files/data/effects/effect-g.sdr b/code/def_files/data/effects/effect-g.sdr
index d1cb2311291..44e8545ee72 100644
--- a/code/def_files/data/effects/effect-g.sdr
+++ b/code/def_files/data/effects/effect-g.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+#endif
+
 layout (points) in;
 layout (triangle_strip, max_vertices = 4) out;
 
diff --git a/code/def_files/data/effects/effect-v.sdr b/code/def_files/data/effects/effect-v.sdr
index 86244a7ee84..3662e9e8649 100644
--- a/code/def_files/data/effects/effect-v.sdr
+++ b/code/def_files/data/effects/effect-v.sdr
@@ -1,3 +1,6 @@
+#ifdef GL_ES
+precision highp float;
+#endif
 
 #ifdef VULKAN
 layout(location = 0) in vec4 vertPosition;
diff --git a/code/def_files/data/effects/envmap-sphere-warp-f.sdr b/code/def_files/data/effects/envmap-sphere-warp-f.sdr
index ab2b4071618..8cc562e693f 100644
--- a/code/def_files/data/effects/envmap-sphere-warp-f.sdr
+++ b/code/def_files/data/effects/envmap-sphere-warp-f.sdr
@@ -1,11 +1,14 @@
 #define M_PI 3.1415926535897932384626433832795
+#ifdef GL_ES
+precision highp float;
+precision highp samplerCube;
+#endif
+
 uniform samplerCube envmap;
 
 in vec4 fragTexCoord;
 
-out vec4 fragOut0;
-
-layout (location = 0) out vec4 outColor;
+layout(location=0) out vec4 fragOut0;
 
 void main() {
 	const float theta = -fragTexCoord.x * (2.0 * M_PI);
diff --git a/code/def_files/data/effects/fog-f.sdr b/code/def_files/data/effects/fog-f.sdr
index 6c822bb67e3..c252e91b611 100644
--- a/code/def_files/data/effects/fog-f.sdr
+++ b/code/def_files/data/effects/fog-f.sdr
@@ -1,17 +1,20 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
 
 #include "gamma.sdr"
 
+layout(location=0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 
 layout(set = 1, binding = 1) uniform sampler2D tex;
 layout(set = 1, binding = 4) uniform sampler2D depth_tex;
 #else
 in vec4 fragTexCoord;
 
-out vec4 fragOut0;
-
 uniform sampler2D tex;
 uniform sampler2D depth_tex;
 #endif
@@ -40,7 +43,7 @@ void main()
 	// If the scene is in fog then we change the color we operate on based on the depth of the pixel
 	float depth_val = texture(depth_tex, fragTexCoord.xy).x;
 	// Transform depth value from [0, 1] to [-1, 1]
-	float depth_normalized = 2 * depth_val - 1;
+	float depth_normalized = 2.0 * depth_val - 1.0;
 	// Now we compute the depth value in projection space using the clipping plane information
 	float view_depth = 2.0 * zNear * zFar / (zFar + zNear - depth_normalized * (zFar - zNear));
 
@@ -50,7 +53,7 @@ void main()
 	if (isinf(view_depth)) {
 		fragOut0.rgb = color_in.rgb;
 	} else {
-		float fog_dist = clamp(1 - pow(fog_density, view_depth - fog_start) , 0.0, 1.0);
+		float fog_dist = clamp(1.0 - pow(fog_density, view_depth - fog_start) , 0.0, 1.0);
 		vec3 finalFogColor = srgb_to_linear(fog_color);
 
 		fragOut0.rgb = mix(color_in.rgb, finalFogColor, fog_dist);
diff --git a/code/def_files/data/effects/fxaa-f.sdr b/code/def_files/data/effects/fxaa-f.sdr
index 329b68384b7..0cd59026d25 100644
--- a/code/def_files/data/effects/fxaa-f.sdr
+++ b/code/def_files/data/effects/fxaa-f.sdr
@@ -1,3 +1,12 @@
+#ifdef GL_ES
+#ifdef GL_EXT_gpu_shader5
+	#extension GL_EXT_gpu_shader5 : enable
+	#define FXAA_GATHER4_ALPHA 1
+#endif
+precision highp float;
+precision highp sampler2D;
+#endif
+
 #define FXAA_EARLY_EXIT 1
 #define FXAA_DISCARD 1
 #define FXAA_FAST_PIXEL_OFFSET 1 // With OpenGL 3.2 we can always do this
@@ -500,8 +509,12 @@ layout(std140, set = 2, binding = 0) uniform genericData {
 #else
 uniform sampler2D tex0;
 in vec2 v_rcpFrame;
+#ifdef GL_ES
+in vec2 v_pos;
+#else
 noperspective in vec2 v_pos;
-out vec4 fragOut0;
+#endif
+layout(location=0)out vec4 fragOut0;
 #endif
 
 void main() {
diff --git a/code/def_files/data/effects/fxaa-v.sdr b/code/def_files/data/effects/fxaa-v.sdr
index 22a9053f2a1..fa5bc259b25 100644
--- a/code/def_files/data/effects/fxaa-v.sdr
+++ b/code/def_files/data/effects/fxaa-v.sdr
@@ -1,3 +1,6 @@
+#ifdef GL_ES
+precision highp float;
+#endif
 
 #ifdef VULKAN
 layout(location = 0) out vec2 fragTexCoord;
@@ -10,7 +13,11 @@ void main() {
 in vec4 vertPosition;
 
 out vec2 v_rcpFrame;
+#ifdef GL_ES
+out vec2 v_pos;
+#else
 noperspective out vec2 v_pos;
+#endif
 
 layout (std140) uniform genericData {
 	float rt_w;
diff --git a/code/def_files/data/effects/fxaapre-f.sdr b/code/def_files/data/effects/fxaapre-f.sdr
index 64dd3487342..a9f6c03c503 100644
--- a/code/def_files/data/effects/fxaapre-f.sdr
+++ b/code/def_files/data/effects/fxaapre-f.sdr
@@ -1,6 +1,12 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
+
+layout(location=0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 // [0]=real color (passed through as-is), [1]=luma detection proxy (see
 // getAADetectionView; may be the same view as [0] when not HDR)
 layout(set = 1, binding = 1) uniform sampler2D fxaaTex[2];
@@ -8,9 +14,9 @@ layout(set = 1, binding = 1) uniform sampler2D fxaaTex[2];
 #define lumaTex fxaaTex[1]
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
 uniform sampler2D tex;
 #endif
+
 void main() {
 	vec4 color = texture(tex, fragTexCoord.xy);
 #ifdef VULKAN
diff --git a/code/def_files/data/effects/gamma-correct-f.sdr b/code/def_files/data/effects/gamma-correct-f.sdr
index dc6ec534257..2f5201fcd1c 100644
--- a/code/def_files/data/effects/gamma-correct-f.sdr
+++ b/code/def_files/data/effects/gamma-correct-f.sdr
@@ -1,12 +1,17 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
+
 #include "gamma.sdr"
 
+layout(location=0)out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform sampler2D tex;
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
 uniform sampler2D tex;
 #endif
 
diff --git a/code/def_files/data/effects/gamma.sdr b/code/def_files/data/effects/gamma.sdr
index a57ce437bdf..7067fef93bf 100644
--- a/code/def_files/data/effects/gamma.sdr
+++ b/code/def_files/data/effects/gamma.sdr
@@ -1,3 +1,6 @@
+#ifdef GL_ES
+precision highp float;
+#endif
 
 const float SRGB_GAMMA = 2.2;
 const float SRGB_GAMMA_INVERSE = 1.0 / SRGB_GAMMA;
diff --git a/code/def_files/data/effects/irrmap-f.sdr b/code/def_files/data/effects/irrmap-f.sdr
index 556480d22e5..ea07011469d 100644
--- a/code/def_files/data/effects/irrmap-f.sdr
+++ b/code/def_files/data/effects/irrmap-f.sdr
@@ -1,15 +1,21 @@
 //!#version 150
-#include "gamma.sdr" //! #include "gamma.sdr"
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp samplerCube;
+#endif
+
+#include "gamma.sdr"
 #define PI 3.1415926535897932384626433832795
 
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform samplerCube envmap;
 #else
 uniform samplerCube envmap;
 in vec4 fragTexCoord;
-out vec4 fragOut0;
 #endif
 
 #ifdef VULKAN
@@ -154,8 +160,8 @@ vec3( 0.7305,  0.6698,  0.1333)
 );
 
 void main() {
-	float xpos = 2 * gl_FragCoord.x/16 - 1; // remap to (-1, 1)
-	float ypos = 2 * gl_FragCoord.y/16 - 1;
+	float xpos = 2.0 * gl_FragCoord.x/16.0 - 1.0; // remap to (-1, 1)
+	float ypos = 2.0 * gl_FragCoord.y/16.0 - 1.0;
 	vec3 fragDir;
 	vec4 fragCol = vec4(0.0);
 
@@ -191,5 +197,5 @@ void main() {
 		vec3 sampDir = points[i] + (aPdotD - PdotD) * fragDir;
 		fragCol += aPdotD * vec4(srgb_to_linear(texture(envmap, sampDir)).rgb, 1.0);
 	}
-	fragOut0 = linear_to_srgb(PI * fragCol * (1.0/128));
+	fragOut0 = linear_to_srgb(PI * fragCol * (1.0/128.0));
 }
\ No newline at end of file
diff --git a/code/def_files/data/effects/lighting.sdr b/code/def_files/data/effects/lighting.sdr
index 799617b52eb..00ae3fb2fa0 100644
--- a/code/def_files/data/effects/lighting.sdr
+++ b/code/def_files/data/effects/lighting.sdr
@@ -8,7 +8,7 @@ const int LT_AMBIENT		= 4;		// Directionless ambient light
 const float SPEC_FACTOR_NO_SPEC_MAP		= 0.1;
 const float GLOW_MAP_INTENSITY			= 1.5;
 const float GLOW_MAP_SRGB_MULTIPLIER	= 3.0;
-const float PI = 3.14159f;
+const float PI = 3.14159265359;
 
 
 vec3 FresnelSchlick(vec3 halfVec, vec3 view, vec3 specColor)
@@ -57,7 +57,7 @@ vec3 ComputeGGX(vec3 specColor, vec3 diffColor, vec3 light, vec3 normal, vec3 ha
 
 
 
-	vec3 specular = distribution * fresnel * geometry / (4*dotNV*dotNL + 0.0001);
+	vec3 specular = distribution * fresnel * geometry / (4.0*dotNV*dotNL + 0.0001);
 	
 	// Diffuse term - Lambertian, kD represents energy lost to specular reflection.
 	vec3 kD = vec3(1.0)-fresnel;
@@ -70,7 +70,7 @@ vec3 ComputeGGX(vec3 specColor, vec3 diffColor, vec3 light, vec3 normal, vec3 ha
 vec3 computeLighting(vec3 specColor, vec3 diffColor, vec3 light, vec3 normal, vec3 halfVec, vec3 view, float roughness, float fresnelFactor, float dotNL) 
 {
 	#ifdef FLAG_LIGHT_MODEL_BLINN_PHONG
-	return SpecularBlinnPhong(specColor, light, normal, halfVec, 32, fresnelFactor, dotNL);
+	return SpecularBlinnPhong(specColor, light, normal, halfVec, 32.0, fresnelFactor, dotNL);
 	#else
 	return ComputeGGX(specColor, diffColor, light, normal, halfVec, view, roughness, fresnelFactor, dotNL);
 	#endif
diff --git a/code/def_files/data/effects/ls-f.sdr b/code/def_files/data/effects/ls-f.sdr
index cc4ff755da0..694ed7f454a 100644
--- a/code/def_files/data/effects/ls-f.sdr
+++ b/code/def_files/data/effects/ls-f.sdr
@@ -1,7 +1,14 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2D;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
 
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
+
 
 layout(set = 1, binding = 1) uniform sampler2D textures[16];
 #define scene textures[0]
@@ -9,8 +16,6 @@ layout(set = 1, binding = 1) uniform sampler2D textures[16];
 #else
 in vec4 fragTexCoord;
 
-out vec4 fragOut0;
-
 uniform sampler2D scene;
 uniform sampler2D cockpit;
 #endif
diff --git a/code/def_files/data/effects/main-f.sdr b/code/def_files/data/effects/main-f.sdr
index 1a46b848d9e..276045c790d 100644
--- a/code/def_files/data/effects/main-f.sdr
+++ b/code/def_files/data/effects/main-f.sdr
@@ -1,4 +1,19 @@
 //? #version 150
+#ifdef GL_ES
+#extension GL_EXT_clip_cull_distance: enable
+precision highp float;
+precision highp int;
+precision highp sampler2D;
+precision highp sampler2DArray;
+precision highp sampler2DArrayShadow;
+#endif
+
+#if defined(VULKAN)
+//define USE_HW_CLIP_DISTANCE from engine side
+#elif !defined(GL_ES) || defined(GL_EXT_clip_cull_distance)
+	#define USE_HW_CLIP_DISTANCE
+#endif
+
 #include "shadows.sdr" //! #include "shadows.sdr"
 #include "lighting.sdr" //! #include "lighting.sdr"
 #include "gamma.sdr" //! #include "gamma.sdr"
@@ -108,6 +123,13 @@ uniform shadowCascadeParams {
 	vec4 smoothness_factors[(NUM_SHADOW_CASCADES + 4 - 1) / 4];
 };
 
+
+layout(location = 0) out vec4 fragOut0;
+layout(location = 1) out vec4 fragOut1;
+layout(location = 2) out vec4 fragOut2;
+layout(location = 3) out vec4 fragOut3;
+layout(location = 4) out vec4 fragOut4;
+
 #ifdef VULKAN
 layout(set = 1, binding = 1) uniform sampler2DArray materialTextures[16];
 #define sBasemap materialTextures[0]
@@ -135,13 +157,12 @@ layout(location = 0) in VertexOutput {
 	vec4 shadowUV[NUM_SHADOW_CASCADES];
 	vec4 shadowPos;
 #prereplace ENDIF_FLAG_COMPILED MODEL_SDR_FLAG_SHADOWS
+
+#ifndef USE_HW_CLIP_DISTANCE
+    float vClipDist;
+#endif
 } vertIn;
 
-layout(location = 0) out vec4 fragOut0;
-layout(location = 1) out vec4 fragOut1;
-layout(location = 2) out vec4 fragOut2;
-layout(location = 3) out vec4 fragOut3;
-layout(location = 4) out vec4 fragOut4;
 #else
 #prereplace IF_FLAG_COMPILED MODEL_SDR_FLAG_DIFFUSE
 uniform sampler2DArray sBasemap;
@@ -181,13 +202,10 @@ in VertexOutput {
 	vec4 shadowUV[NUM_SHADOW_CASCADES];
 	vec4 shadowPos;
 #prereplace ENDIF_FLAG_COMPILED MODEL_SDR_FLAG_SHADOWS
+#ifndef USE_HW_CLIP_DISTANCE
+    float vClipDist;
+#endif
 } vertIn;
-
-out vec4 fragOut0;
-out vec4 fragOut1;
-out vec4 fragOut2;
-out vec4 fragOut3;
-out vec4 fragOut4;
 #endif
 
 vec3 FresnelLazarovEnv(vec3 specColor, vec3 view, vec3 normal, float gloss)
@@ -272,6 +290,10 @@ vec3 CalculateLighting(vec3 normal, vec3 diffuseMaterial, vec3 specularMaterial,
 
 void main()
 {
+	#ifndef USE_HW_CLIP_DISTANCE
+		if (vertIn.vClipDist < 0.0) discard;
+	#endif
+
 	vec3 eyeDir = vec3(normalize(-vertIn.position).xyz);
 	vec2 texCoord = vertIn.texCoord.xy;
 
@@ -448,7 +470,7 @@ void main()
 		#prereplace ENDIF_FLAG //MODEL_SDR_FLAG_DIFFUSE
 		// This code will only be used by the forward renderer so we apply the fog effect to both the emissive and the base
 		// color.
-		float fogDensityFinal = clamp(1 - pow(fogDensity, vertIn.fogDist) , 0.0, 1.0);
+		float fogDensityFinal = clamp(1.0 - pow(fogDensity, vertIn.fogDist) , 0.0, 1.0);
 		baseColor.rgb = mix(emissiveColor.rgb + baseColor.rgb, finalFogColor, fogDensityFinal);
 		emissiveColor.rgb = vec3(0.0); // Zero the emissive color since it has already been added by the previous line
 		specColor.rgb *= fogDensityFinal;
@@ -493,11 +515,11 @@ void main()
 		#prereplace IF_NOT_FLAG MODEL_SDR_FLAG_LIGHT
 			#prereplace IF_FLAG MODEL_SDR_FLAG_SPEC
 				baseColor.rgb += pow(1.0 - clamp(dot(eyeDir, normal), 0.0, 1.0), 5.0 * clamp(glossData, 0.01, 1.0)) * specColor.rgb;
-				glossData = 0;
+				glossData = 0.0f;
 			#prereplace ENDIF_FLAG //MODEL_SDR_FLAG_SPEC
 			// If there is no lighting then we copy the color data so far into the emissive.
 			emissiveColor.rgb += baseColor.rgb;
-			aoFactors.x = 0;
+			aoFactors.x = 0.0f;
 		#prereplace ENDIF_FLAG //MODEL_SDR_FLAG_LIGHT
 	#prereplace ENDIF_FLAG //MODEL_SDR_FLAG_DEFERRED
 
diff --git a/code/def_files/data/effects/main-g.sdr b/code/def_files/data/effects/main-g.sdr
index e348c386dfa..4e28e913d72 100644
--- a/code/def_files/data/effects/main-g.sdr
+++ b/code/def_files/data/effects/main-g.sdr
@@ -1,4 +1,17 @@
+#ifdef GL_ES
+#extension GL_EXT_gpu_shader5: enable
+#extension GL_EXT_clip_cull_distance: enable
+precision highp float;
+precision highp int;
+#else
 #extension GL_ARB_gpu_shader5: enable
+#endif
+
+#if defined(VULKAN)
+//define USE_HW_CLIP_DISTANCE from engine side
+#elif !defined(GL_ES) || defined(GL_EXT_clip_cull_distance)
+	#define USE_HW_CLIP_DISTANCE
+#endif
 
 #conditional_include +"LARGE_SHADER" "main_large.sdr"
 #conditional_include -"LARGE_SHADER" "main_small.sdr"
@@ -100,6 +113,9 @@ in VertexOutput {
 	vec4 shadowUV[NUM_SHADOW_CASCADES];
 	vec4 shadowPos;
 #prereplace ENDIF_FLAG_COMPILED MODEL_SDR_FLAG_SHADOWS
+#ifndef USE_HW_CLIP_DISTANCE
+    float vClipDist;
+#endif
 } vertIn[];
 
 out VertexOutput {
@@ -117,6 +133,10 @@ out VertexOutput {
 	vec4 shadowUV[NUM_SHADOW_CASCADES];
 	vec4 shadowPos;
 #prereplace ENDIF_FLAG_COMPILED MODEL_SDR_FLAG_SHADOWS
+
+#ifndef USE_HW_CLIP_DISTANCE
+    float vClipDist;
+#endif
 } vertOut;
 
 #ifdef MODEL_SDR_FLAG_THICK_OUTLINES
@@ -166,8 +186,19 @@ out VertexOutput {
                 #prereplace ENDIF_FLAG //MODEL_SDR_FLAG_SHADOWS
 
 				if (use_clip_plane != 0) {
-					gl_ClipDistance[0] = gl_in[vert].gl_ClipDistance[0];
+					#ifndef USE_HW_CLIP_DISTANCE
+						vertOut.vClipDist = vertIn[vert].vClipDist;
+					#else
+						gl_ClipDistance[0] = gl_in[vert].gl_ClipDistance[0];
+					#endif
+				} else {
+					#ifndef USE_HW_CLIP_DISTANCE
+						vertOut.vClipDist = 1.0;
+					#else
+						gl_ClipDistance[0] = 1.0;
+					#endif
 				}
+
 				EmitVertex();
 			}
 
diff --git a/code/def_files/data/effects/main-v.sdr b/code/def_files/data/effects/main-v.sdr
index 39426766ab1..66d4c2a73d8 100644
--- a/code/def_files/data/effects/main-v.sdr
+++ b/code/def_files/data/effects/main-v.sdr
@@ -1,8 +1,24 @@
 
 #ifndef VULKAN
 //? #version 150
+#ifdef GL_ES
+#extension GL_EXT_gpu_shader5: enable
+#extension GL_EXT_clip_cull_distance: enable
+precision highp float;
+precision highp int;
+precision highp samplerBuffer;
+precision highp sampler2DArrayShadow;
+#else
 #extension GL_ARB_gpu_shader5: enable
 #endif
+#endif
+
+#if defined(VULKAN)
+//define USE_HW_CLIP_DISTANCE from engine side
+#elif !defined(GL_ES) || defined(GL_EXT_clip_cull_distance)
+	#define USE_HW_CLIP_DISTANCE
+#endif
+
 #include "shadows.sdr"
 
 #conditional_include +"LARGE_SHADER" "main_large.sdr"
@@ -135,8 +151,15 @@ layout(location = 0) out VertexOutput {
 	vec4 texCoord;
 	mat3 tangentMatrix;
 	float fogDist;
+
+#prereplace IF_FLAG_COMPILED MODEL_SDR_FLAG_SHADOWS
 	vec4 shadowUV[NUM_SHADOW_CASCADES];
 	vec4 shadowPos;
+#prereplace ENDIF_FLAG_COMPILED MODEL_SDR_FLAG_SHADOWS
+
+#ifndef USE_HW_CLIP_DISTANCE
+    float vClipDist;
+#endif
 } vertOut;
 #else
 #prereplace IF_FLAG_COMPILED MODEL_SDR_FLAG_TRANSFORM
@@ -158,6 +181,10 @@ out VertexOutput {
 	vec4 shadowUV[NUM_SHADOW_CASCADES];
 	vec4 shadowPos;
 #prereplace ENDIF_FLAG_COMPILED MODEL_SDR_FLAG_SHADOWS
+
+#ifndef USE_HW_CLIP_DISTANCE
+    float vClipDist;
+#endif
 } vertOut;
 
 #define TEXELS_PER_MATRIX 4
@@ -239,12 +266,20 @@ void main()
 		}
 	#prereplace ENDIF_FLAG //MODEL_SDR_FLAG_TRANSFORM
 
-	// Clip plane
-	if(use_clip_plane != 0) {
-		gl_ClipDistance[0] = dot(clip_equation, modelMatrix * orient * vertex);
-	} else {
-		gl_ClipDistance[0] = 1.0;
-	}
+	#ifdef USE_HW_CLIP_DISTANCE
+		if (use_clip_plane != 0) {
+			gl_ClipDistance[0] = dot(clip_equation, modelMatrix * orient * vertex);
+		} else {
+			gl_ClipDistance[0] = 1.0;
+		}
+	#else
+		if (use_clip_plane != 0) {
+			vertOut.vClipDist = dot(clip_equation, modelMatrix * orient * vertex);
+		} else {
+			vertOut.vClipDist = 1.0;
+		}
+	#endif
+
 
 	vertOut.position = position;
 	vertOut.normal = normal;
diff --git a/code/def_files/data/effects/msaa-f.sdr b/code/def_files/data/effects/msaa-f.sdr
index 85ce8d36aff..002abf1e025 100644
--- a/code/def_files/data/effects/msaa-f.sdr
+++ b/code/def_files/data/effects/msaa-f.sdr
@@ -1,7 +1,9 @@
 #include "z-compress.sdr"
-
-#ifdef VULKAN
-layout(location = 0) in vec2 fragTexCoord;
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2DMS;
+#endif
 
 layout(location = 0) out vec4 fragOut0;
 layout(location = 1) out vec4 fragOut1;
@@ -9,6 +11,9 @@ layout(location = 2) out vec4 fragOut2;
 layout(location = 3) out vec4 fragOut3;
 layout(location = 4) out vec4 fragOut4;
 
+#ifdef VULKAN
+layout(location = 0) in vec2 fragTexCoord;
+
 layout(set = 1, binding = 1) uniform sampler2DMS msaaTex[6];
 #define texColor    msaaTex[0]
 #define texPos      msaaTex[1]
@@ -23,12 +28,7 @@ layout(std140, set = 2, binding = 0) uniform genericData {
 };
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
-out vec4 fragOut1;
-out vec4 fragOut2;
-out vec4 fragOut3;
-out vec4 fragOut4;
-out vec4 fragOut5;
+layout(location=5)out vec4 fragOut5;
 
 uniform sampler2DMS texColor;
 uniform sampler2DMS texPos;
diff --git a/code/def_files/data/effects/nanovg-f.sdr b/code/def_files/data/effects/nanovg-f.sdr
index dbe41703069..4ba74a86c98 100644
--- a/code/def_files/data/effects/nanovg-f.sdr
+++ b/code/def_files/data/effects/nanovg-f.sdr
@@ -1,3 +1,8 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2DArray;
+#endif
 
 #ifdef VULKAN
 layout (location = 0) in vec2 ftcoord;
diff --git a/code/def_files/data/effects/nanovg-v.sdr b/code/def_files/data/effects/nanovg-v.sdr
index 2974de708e1..89a56d5a4cd 100644
--- a/code/def_files/data/effects/nanovg-v.sdr
+++ b/code/def_files/data/effects/nanovg-v.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+#endif
 
 #ifdef VULKAN
 layout (location = 0) in vec4 vertPosition;
diff --git a/code/def_files/data/effects/normals.sdr b/code/def_files/data/effects/normals.sdr
index 8123bd13747..185dc5cbff2 100644
--- a/code/def_files/data/effects/normals.sdr
+++ b/code/def_files/data/effects/normals.sdr
@@ -7,6 +7,6 @@
 vec3 unpackNormal(vec2 normal_sample) {
 	vec3 normal;
 	normal.xy = normal_sample * 2.0 - 1.0;
-	normal.z = sqrt(1 - normal_sample.x * normal_sample.x - normal_sample.y * normal_sample.y);
+	normal.z = sqrt(1.0 - normal_sample.x * normal_sample.x - normal_sample.y * normal_sample.y);
 	return normal;
 }
diff --git a/code/def_files/data/effects/passthrough-f.sdr b/code/def_files/data/effects/passthrough-f.sdr
index 6e3134e068e..3b06379b9bd 100644
--- a/code/def_files/data/effects/passthrough-f.sdr
+++ b/code/def_files/data/effects/passthrough-f.sdr
@@ -1,9 +1,14 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2D;
+#endif
 
 #include "gamma.sdr"
 
 in vec4 fragTexCoord;
 in vec4 fragColor;
-out vec4 fragOut0;
+layout(location=0) out vec4 fragOut0;
 
 uniform sampler2D baseMap;
 
diff --git a/code/def_files/data/effects/post-f.sdr b/code/def_files/data/effects/post-f.sdr
index 6e12a5e20fb..29bc2a78ae7 100644
--- a/code/def_files/data/effects/post-f.sdr
+++ b/code/def_files/data/effects/post-f.sdr
@@ -1,11 +1,16 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform sampler2D tex;
 layout(set = 1, binding = 4) uniform sampler2D depth_tex;
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
 uniform sampler2D tex;
 uniform sampler2D depth_tex;
 #endif
diff --git a/code/def_files/data/effects/rocketui-f.sdr b/code/def_files/data/effects/rocketui-f.sdr
index 688d2ec5fe2..a3559ab4b89 100644
--- a/code/def_files/data/effects/rocketui-f.sdr
+++ b/code/def_files/data/effects/rocketui-f.sdr
@@ -1,10 +1,17 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2DArray;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
 
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
 layout(location = 1) in vec4 fragColor;
 layout(location = 2) in vec2 fragScreenPosition;
 
-layout(location = 0) out vec4 fragOut0;
+
 
 layout(set = 1, binding = 1) uniform sampler2DArray baseMap;
 #else
@@ -12,8 +19,6 @@ in vec2 fragTexCoord;
 in vec4 fragColor;
 in vec2 fragScreenPosition;
 
-out vec4 fragOut0;
-
 uniform sampler2DArray baseMap;
 #endif
 
diff --git a/code/def_files/data/effects/rocketui-v.sdr b/code/def_files/data/effects/rocketui-v.sdr
index 07ae245966f..df966d8a1de 100644
--- a/code/def_files/data/effects/rocketui-v.sdr
+++ b/code/def_files/data/effects/rocketui-v.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+#endif
 
 #ifdef VULKAN
 layout(location = 0) in vec2 vertPosition;
diff --git a/code/def_files/data/effects/shadow_map-f.sdr b/code/def_files/data/effects/shadow_map-f.sdr
index fff405831fd..652cacb5b64 100644
--- a/code/def_files/data/effects/shadow_map-f.sdr
+++ b/code/def_files/data/effects/shadow_map-f.sdr
@@ -1,5 +1,30 @@
 //? #version 150
+#ifdef GL_ES
+#extension GL_EXT_clip_cull_distance: enable
+precision highp float;
+#endif
+
+#if defined(VULKAN)
+//define USE_HW_CLIP_DISTANCE from engine side
+#elif !defined(GL_ES) || defined(GL_EXT_clip_cull_distance)
+	#define USE_HW_CLIP_DISTANCE
+#endif
+
+#ifndef USE_HW_CLIP_DISTANCE
+#ifdef VULKAN
+layout(location = 0) in VertexOutput {
+	float vClipDist;
+} vertIn;
+#else
+in VertexOutput {
+	float vClipDist;
+} vertIn;
+#endif
+#endif
 
 void main()
 {
+#ifndef USE_HW_CLIP_DISTANCE
+	if (vertIn.vClipDist < 0.0) discard;
+#endif
 }
diff --git a/code/def_files/data/effects/shadow_map-g.sdr b/code/def_files/data/effects/shadow_map-g.sdr
index 585276dca69..0f13cb1d1ee 100644
--- a/code/def_files/data/effects/shadow_map-g.sdr
+++ b/code/def_files/data/effects/shadow_map-g.sdr
@@ -1,9 +1,22 @@
 //? #version 150
+#ifdef GL_ES
+#extension GL_EXT_gpu_shader5: enable
+#extension GL_EXT_clip_cull_distance: enable
+precision highp float;
+precision highp int;
+#else
 #extension GL_ARB_gpu_shader5: enable
+#endif
+
+#if defined(VULKAN)
+//define USE_HW_CLIP_DISTANCE from engine side
+#elif !defined(GL_ES) || defined(GL_EXT_clip_cull_distance)
+	#define USE_HW_CLIP_DISTANCE
+#endif
 
 layout (triangles) in;
 layout (triangle_strip, max_vertices = 3) out;
-#ifdef GL_ARB_gpu_shader5
+#if defined(GL_ARB_gpu_shader5) || defined(GL_EXT_gpu_shader5)
 layout(invocations = NUM_SHADOW_CASCADES) in;
 #endif
 
@@ -20,16 +33,25 @@ layout (std140) uniform shadowCascadeParams {
 };
 
 in VertexOutput {
-#if !defined(GL_ARB_gpu_shader5)
+#if !defined(GL_ARB_gpu_shader5) && !defined(GL_EXT_gpu_shader5)
     float instance;
 #endif
 	float clipModel;
 	vec3 normal;
+#ifndef USE_HW_CLIP_DISTANCE
+	float vClipDist;
+#endif
 } vertIn[];
 
+#ifndef USE_HW_CLIP_DISTANCE
+out VertexOutput {
+	float vClipDist;
+} vertOut;
+#endif
+
 void main(void)
 {
-#ifdef GL_ARB_gpu_shader5
+#if defined(GL_ARB_gpu_shader5) || defined(GL_EXT_gpu_shader5)
     if (gl_InvocationID >= cascade_count) return;
     int cascade_id = cascade_offset + gl_InvocationID;
 #else
@@ -45,7 +67,12 @@ void main(void)
 		}
 
 		gl_Layer = cascade_id;
-		gl_ClipDistance[0] = gl_in[vert].gl_ClipDistance[0];
+		
+		#ifndef USE_HW_CLIP_DISTANCE
+			vertOut.vClipDist = vertIn[vert].vClipDist;
+		#else
+			gl_ClipDistance[0] = gl_in[vert].gl_ClipDistance[0];
+		#endif
 
 		EmitVertex();
 	}
diff --git a/code/def_files/data/effects/shadow_map-v.sdr b/code/def_files/data/effects/shadow_map-v.sdr
index f3e92cd21d1..15a2f368bcc 100644
--- a/code/def_files/data/effects/shadow_map-v.sdr
+++ b/code/def_files/data/effects/shadow_map-v.sdr
@@ -1,9 +1,22 @@
 //? #version 150
+#ifdef GL_ES
+#extension GL_EXT_gpu_shader5: enable
+#extension GL_EXT_clip_cull_distance: enable
+precision highp float;
+precision highp int;
+precision highp samplerBuffer;
+#else
 #extension GL_ARB_gpu_shader5: enable
-
 #ifndef GEOMETRY_FALLBACK
 #extension GL_ARB_shader_viewport_layer_array : enable
 #endif
+#endif
+
+#if defined(VULKAN)
+//define USE_HW_CLIP_DISTANCE from engine side
+#elif !defined(GL_ES) || defined(GL_EXT_clip_cull_distance)
+	#define USE_HW_CLIP_DISTANCE
+#endif
 
 #ifdef VULKAN
 layout(location = 0) in vec4 vertPosition;
@@ -62,13 +75,26 @@ uniform samplerBuffer transform_tex;
 // supports writing gl_Layer from the vertex shader, see CAPABILITY_FAST_SHADOWS).
 #ifdef GEOMETRY_FALLBACK
 out VertexOutput {
-#if !defined(GL_ARB_gpu_shader5)
+#if !defined(GL_ARB_gpu_shader5) && !defined(GL_EXT_gpu_shader5)
 	float instance;
 #endif
 	float clipModel;
 	vec3 normal;
+#ifndef USE_HW_CLIP_DISTANCE
+    float vClipDist;
+#endif
+} vertOut;
+#elif !defined(USE_HW_CLIP_DISTANCE)
+#ifdef VULKAN
+layout(location = 0) out VertexOutput {
+	float vClipDist;
+} vertOut;
+#else
+out VertexOutput {
+	float vClipDist;
 } vertOut;
 #endif
+#endif
 
 #define TEXELS_PER_MATRIX 4
 
@@ -108,7 +134,7 @@ void main()
 #ifdef VULKAN
 	int instanceIndex = gl_InstanceIndex;
 #else
-	#if !defined(GL_ARB_gpu_shader5)
+	#if !defined(GL_ARB_gpu_shader5) && !defined(GL_EXT_gpu_shader5)
 		#ifdef APPLE
 			vertOut.instance = float(gl_InstanceIDARB);
 		#else
@@ -129,11 +155,19 @@ void main()
         gl_Position = position;
     }
 
+#ifdef USE_HW_CLIP_DISTANCE
 	if (use_clip_plane != 0) {
 		gl_ClipDistance[0] = dot(clip_equation, modelMatrix * orient * vertex);
 	} else {
 		gl_ClipDistance[0] = 1.0;
 	}
+#else
+	if (use_clip_plane != 0) {
+		vertOut.vClipDist = dot(clip_equation, modelMatrix * orient * vertex);
+	} else {
+		vertOut.vClipDist = 1.0;
+	}
+#endif
 
 #ifdef GEOMETRY_FALLBACK
     vertOut.normal = normal;
diff --git a/code/def_files/data/effects/shield-impact-f.sdr b/code/def_files/data/effects/shield-impact-f.sdr
index e847867a9b0..fbdc1ecd141 100644
--- a/code/def_files/data/effects/shield-impact-f.sdr
+++ b/code/def_files/data/effects/shield-impact-f.sdr
@@ -1,21 +1,22 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2DArray;
+#endif
 
 #include "gamma.sdr"
 
 const float EMISSIVE_GAIN = 2.0;
 
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec4 fragImpactUV;
 layout(location = 1) in float fragNormOffset;
-
-layout(location = 0) out vec4 fragOut0;
-
 layout(set = 1, binding = 1) uniform sampler2DArray shieldMap;
 #else
 in vec4 fragImpactUV;
 in float fragNormOffset;
-
-out vec4 fragOut0;
-
 uniform sampler2DArray shieldMap;
 #endif
 
diff --git a/code/def_files/data/effects/shield-impact-v.sdr b/code/def_files/data/effects/shield-impact-v.sdr
index 22f423cb3fb..ee078d041ac 100644
--- a/code/def_files/data/effects/shield-impact-v.sdr
+++ b/code/def_files/data/effects/shield-impact-v.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+#endif
 
 #ifdef VULKAN
 layout(location = 0) in vec4 vertPosition;
diff --git a/code/def_files/data/effects/smaa-blend-f.sdr b/code/def_files/data/effects/smaa-blend-f.sdr
index 055d4b617b5..cbb8f3a5917 100644
--- a/code/def_files/data/effects/smaa-blend-f.sdr
+++ b/code/def_files/data/effects/smaa-blend-f.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
 
 #ifdef VULKAN
 layout(std140, set = 2, binding = 0) uniform genericData {
@@ -16,13 +20,13 @@ layout (std140) uniform genericData {
 
 #include "SMAA.sdr"
 
+layout(location=0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
 layout(location = 1) in vec2 fragPixcoord;
 layout(location = 2) in vec4 fragOffset[3];
 
-layout(location = 0) out vec4 fragOut0;
-
 // [0]=edgesTex, [1]=areaTex, [2]=searchTex
 layout(set = 1, binding = 1) uniform sampler2D smaaTex[3];
 #define edgesTex smaaTex[0]
@@ -33,8 +37,6 @@ in vec2 fragTexCoord;
 in vec2 fragPixcoord;
 in vec4 fragOffset[3];
 
-out vec4 fragOut0;
-
 uniform sampler2D edgesTex;
 uniform sampler2D areaTex;
 uniform sampler2D searchTex;
diff --git a/code/def_files/data/effects/smaa-blend-v.sdr b/code/def_files/data/effects/smaa-blend-v.sdr
index a4e51c82a23..b04347279db 100644
--- a/code/def_files/data/effects/smaa-blend-v.sdr
+++ b/code/def_files/data/effects/smaa-blend-v.sdr
@@ -1,4 +1,3 @@
-
 #ifdef VULKAN
 layout(std140, set = 2, binding = 0) uniform genericData {
 	vec2 smaa_rt_metrics;
diff --git a/code/def_files/data/effects/smaa-edge-f.sdr b/code/def_files/data/effects/smaa-edge-f.sdr
index 3628177a08e..24e27ee0dc7 100644
--- a/code/def_files/data/effects/smaa-edge-f.sdr
+++ b/code/def_files/data/effects/smaa-edge-f.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
 
 #ifdef VULKAN
 layout(std140, set = 2, binding = 0) uniform genericData {
@@ -16,19 +20,17 @@ layout (std140) uniform genericData {
 
 #include "SMAA.sdr"
 
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
 layout(location = 1) in vec4 fragOffset[3];
 
-layout(location = 0) out vec4 fragOut0;
-
 layout(set = 1, binding = 1) uniform sampler2D colorTex;
 #else
 in vec2 fragTexCoord;
 in vec4 fragOffset[3];
 
-out vec4 fragOut0;
-
 uniform sampler2D colorTex;
 #endif
 
diff --git a/code/def_files/data/effects/smaa-edge-v.sdr b/code/def_files/data/effects/smaa-edge-v.sdr
index 6aa82772665..2983e60d044 100644
--- a/code/def_files/data/effects/smaa-edge-v.sdr
+++ b/code/def_files/data/effects/smaa-edge-v.sdr
@@ -1,4 +1,3 @@
-
 #ifdef VULKAN
 layout(std140, set = 2, binding = 0) uniform genericData {
 	vec2 smaa_rt_metrics;
diff --git a/code/def_files/data/effects/smaa-neighbour-f.sdr b/code/def_files/data/effects/smaa-neighbour-f.sdr
index 56813d9ca59..18973d57d42 100644
--- a/code/def_files/data/effects/smaa-neighbour-f.sdr
+++ b/code/def_files/data/effects/smaa-neighbour-f.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
 
 #ifdef VULKAN
 layout(std140, set = 2, binding = 0) uniform genericData {
@@ -16,11 +20,12 @@ layout (std140) uniform genericData {
 
 #include "SMAA.sdr"
 
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
 layout(location = 1) in vec4 fragOffset;
 
-layout(location = 0) out vec4 fragOut0;
 
 // [0]=colorTex, [1]=blendTex
 layout(set = 1, binding = 1) uniform sampler2D smaaTex[2];
@@ -30,8 +35,6 @@ layout(set = 1, binding = 1) uniform sampler2D smaaTex[2];
 in vec2 fragTexCoord;
 in vec4 fragOffset;
 
-out vec4 fragOut0;
-
 uniform sampler2D colorTex;
 uniform sampler2D blendTex;
 #endif
diff --git a/code/def_files/data/effects/smaa-neighbour-v.sdr b/code/def_files/data/effects/smaa-neighbour-v.sdr
index 98ca74070c0..de4ad607df7 100644
--- a/code/def_files/data/effects/smaa-neighbour-v.sdr
+++ b/code/def_files/data/effects/smaa-neighbour-v.sdr
@@ -1,4 +1,3 @@
-
 #ifdef VULKAN
 layout(std140, set = 2, binding = 0) uniform genericData {
 	vec2 smaa_rt_metrics;
diff --git a/code/def_files/data/effects/smaa-resolve-f.sdr b/code/def_files/data/effects/smaa-resolve-f.sdr
index fffe9367416..b9a22ed90d8 100644
--- a/code/def_files/data/effects/smaa-resolve-f.sdr
+++ b/code/def_files/data/effects/smaa-resolve-f.sdr
@@ -1,10 +1,14 @@
+#ifdef GL_ES
+precision highp sampler2D;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform sampler2D tex;
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
 uniform sampler2D tex;
 #endif
 
diff --git a/code/def_files/data/effects/tonemapping-f.sdr b/code/def_files/data/effects/tonemapping-f.sdr
index 98d7a04838b..93d12a134cb 100644
--- a/code/def_files/data/effects/tonemapping-f.sdr
+++ b/code/def_files/data/effects/tonemapping-f.sdr
@@ -1,13 +1,18 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2D;
+#endif
 
 #include "gamma.sdr"
 
+layout(location=0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform sampler2D tex;
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
 uniform sampler2D tex;
 #endif
 
diff --git a/code/def_files/data/effects/video-f.sdr b/code/def_files/data/effects/video-f.sdr
index 8ea4044baa3..0322b26813f 100644
--- a/code/def_files/data/effects/video-f.sdr
+++ b/code/def_files/data/effects/video-f.sdr
@@ -1,6 +1,12 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2DArray;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec4 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 
 layout(set = 1, binding = 1) uniform sampler2DArray textures[16];
 #define ytex textures[0]
@@ -8,7 +14,6 @@ layout(set = 1, binding = 1) uniform sampler2DArray textures[16];
 #define vtex textures[2]
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
 uniform sampler2DArray ytex;
 uniform sampler2DArray utex;
 uniform sampler2DArray vtex;
diff --git a/code/def_files/data/effects/volumetric-f.sdr b/code/def_files/data/effects/volumetric-f.sdr
index b00e721317c..f1e8726a0ab 100644
--- a/code/def_files/data/effects/volumetric-f.sdr
+++ b/code/def_files/data/effects/volumetric-f.sdr
@@ -1,7 +1,13 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2D;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
 
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform sampler2D tex2D[16];
 #define composite tex2D[0]
 #define emissive tex2D[1]
@@ -10,7 +16,7 @@ layout(set = 1, binding = 5) uniform sampler3D volume_tex;
 layout(set = 1, binding = 6) uniform sampler3D noise_volume_tex;
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
+
 layout (binding = 0) uniform sampler2D composite;
 layout (binding = 1) uniform sampler2D emissive;
 layout (binding = 2) uniform sampler2D depth_tex;
diff --git a/code/graphics/opengl/es_compatibility.h b/code/graphics/opengl/es_compatibility.h
index a864be1545e..3cdae8eeb82 100644
--- a/code/graphics/opengl/es_compatibility.h
+++ b/code/graphics/opengl/es_compatibility.h
@@ -32,6 +32,7 @@
 #define GL_CLAMP_VERTEX_COLOR					0x891A
 #define GL_CLAMP_FRAGMENT_COLOR					0x891B
 #define GL_FIXED_ONLY							0x891D
+#define GLAD_GL_ARB_shader_viewport_layer_array 0 // Disabled, no gl_layer in vertex shader //0x8DAE
 
 //Enums Redefinitions
 #define GL_CLIP_DISTANCE0						GL_CLIP_DISTANCE0_EXT // GL_EXT_clip_cull_distance
@@ -48,6 +49,7 @@
 #define GLAD_GL_ARB_texture_storage				GL_TRUE // ES 3.2
 #define GLAD_GL_ARB_draw_buffers_blend			GL_TRUE // ES 3.2 (glBlendFunci and glBlendEquationi)
 #define GLAD_GL_ARB_vertex_attrib_binding		GL_TRUE // ES 3.1
+#define GL_DEPTH_CLAMP							GL_DEPTH_CLAMP_EXT
 
 //Functions Redefinitions
 #define glBlendFunciARB					glBlendFunci // ES 3.2
@@ -234,11 +236,6 @@ inline void glDrawBuffer(GLenum buf)
 	}
 }
 
-// does not exist on ES, ES uses layout(location=) directly on shader
-// Notes: 
-// -This function is not required to run.
-#define glBindFragDataLocation(program, colorNumber, name) ((void)0)
-
 // glPolygonMode() is not supported on ES,  no wireframe, GL_FILL is default, GL_POINTS, and GL_LINES needs an alternative path
 // Notes: 
 // -This function is not required to run.
@@ -254,6 +251,7 @@ static inline void glQueryCounter(GLuint id, GLenum target)
 	#else
 		(void)id;
 	#endif
+		(void)target;
 }
 
 // glGetCompressedTexImage not present on GLES and no equivalent
diff --git a/code/graphics/opengl/gropengl.cpp b/code/graphics/opengl/gropengl.cpp
index 444515b797a..ea3b337eeec 100644
--- a/code/graphics/opengl/gropengl.cpp
+++ b/code/graphics/opengl/gropengl.cpp
@@ -1453,7 +1453,9 @@ bool gr_opengl_init(std::unique_ptr<os::GraphicsOperations>&& graphicsOps)
 			"Deferred lightning is enabled in settings but the gpu does not support the minimum of 6 draw buffers. "
 			"This will result in rendering errors.");
 	}
-
+	
+	mprintf(("  Depth Clamp support : %s\n", GLAD_GL_EXT_depth_clamp ? NOX("YES") : NOX("NO")));
+	mprintf(("  HW Cull distance support : %s\n", GLAD_GL_EXT_clip_cull_distance ? NOX("YES") : NOX("NO")));
 	mprintf(("  Precompiled shaders support : %s\n", GLAD_GL_OES_get_program_binary ? NOX("YES") : NOX("NO")));
 	mprintf(("  Immutable buffer storage support : %s\n", GLAD_GL_EXT_buffer_storage ? NOX("YES") : NOX("NO")));
 	mprintf(("  BGRA8888 format support: %s\n", GLAD_GL_EXT_texture_format_BGRA8888 ? NOX("YES") : NOX("NO")));
diff --git a/code/graphics/opengl/gropenglshader.cpp b/code/graphics/opengl/gropenglshader.cpp
index 41c3142d153..f2e5e5a768f 100644
--- a/code/graphics/opengl/gropenglshader.cpp
+++ b/code/graphics/opengl/gropenglshader.cpp
@@ -488,13 +488,6 @@ void opengl_compile_shader_actual(shader_type sdr, const uint &flags, opengl_sha
 				glBindAttribLocation(program->getShaderHandle(), (GLint)i, GL_vertex_attrib_info[i].name.c_str());
 			}
 
-			// bind fragment data locations before we link the shader
-			glBindFragDataLocation(program->getShaderHandle(), 0, "fragOut0");
-			glBindFragDataLocation(program->getShaderHandle(), 1, "fragOut1");
-			glBindFragDataLocation(program->getShaderHandle(), 2, "fragOut2");
-			glBindFragDataLocation(program->getShaderHandle(), 3, "fragOut3");
-			glBindFragDataLocation(program->getShaderHandle(), 4, "fragOut4");
-
 			if (do_shader_caching()) {
 				// Enable shader caching
 				glProgramParameteri(program->getShaderHandle(), GL_PROGRAM_BINARY_RETRIEVABLE_HINT, GL_TRUE);
diff --git a/code/graphics/vulkan/VulkanRendererSetup.cpp b/code/graphics/vulkan/VulkanRendererSetup.cpp
index 90ebc51b567..8b0b673a6d0 100644
--- a/code/graphics/vulkan/VulkanRendererSetup.cpp
+++ b/code/graphics/vulkan/VulkanRendererSetup.cpp
@@ -426,7 +426,7 @@ bool VulkanRenderer::initialize()
 
 	// Initialize shader manager
 	m_shaderManager = std::make_unique<VulkanShaderManager>();
-	if (!m_shaderManager->init(m_device.get())) {
+	if (!m_shaderManager->init(m_device.get(), m_deviceFeatures.shaderClipDistance == VK_TRUE)) {
 		nprintf(("vulkan", "Failed to initialize Vulkan shader manager!\n"));
 		return false;
 	}
diff --git a/code/graphics/vulkan/VulkanShader.cpp b/code/graphics/vulkan/VulkanShader.cpp
index da9a29bc5dc..d1e7763fb05 100644
--- a/code/graphics/vulkan/VulkanShader.cpp
+++ b/code/graphics/vulkan/VulkanShader.cpp
@@ -34,7 +34,7 @@ void vulkan_recompile_all_shaders(const std::function<void(size_t, size_t)>& pro
 VulkanShaderManager::VulkanShaderManager() = default;
 VulkanShaderManager::~VulkanShaderManager() = default;
 
-bool VulkanShaderManager::init(vk::Device device)
+bool VulkanShaderManager::init(vk::Device device, bool hwClipDistance)
 {
 	if (m_initialized) {
 		return true;
@@ -44,7 +44,7 @@ bool VulkanShaderManager::init(vk::Device device)
 
 	// Initialize runtime shader compiler
 	m_compiler = std::make_unique<VulkanShaderCompiler>();
-	if (!m_compiler->init()) {
+	if (!m_compiler->init(hwClipDistance)) {
 		nprintf(("vulkan", "VulkanShaderManager: Failed to initialize shader compiler!\n"));
 		return false;
 	}
diff --git a/code/graphics/vulkan/VulkanShader.h b/code/graphics/vulkan/VulkanShader.h
index 0f3e13381cb..25a1c724ee9 100644
--- a/code/graphics/vulkan/VulkanShader.h
+++ b/code/graphics/vulkan/VulkanShader.h
@@ -59,7 +59,7 @@ class VulkanShaderManager {
 	 * @param device Vulkan logical device
 	 * @return true on success
 	 */
-	bool init(vk::Device device);
+	bool init(vk::Device device, bool hwClipDistance);
 
 	/**
 	 * @brief Shutdown and release all shader modules
diff --git a/code/graphics/vulkan/VulkanShaderCompiler.cpp b/code/graphics/vulkan/VulkanShaderCompiler.cpp
index 2ff077b19ed..39ec38f7e40 100644
--- a/code/graphics/vulkan/VulkanShaderCompiler.cpp
+++ b/code/graphics/vulkan/VulkanShaderCompiler.cpp
@@ -102,8 +102,9 @@ VulkanShadercLibrary::VulkanShadercLibrary()
 VulkanShaderCompiler::VulkanShaderCompiler() = default;
 VulkanShaderCompiler::~VulkanShaderCompiler() = default;
 
-bool VulkanShaderCompiler::init()
+bool VulkanShaderCompiler::init(bool hwClipDistance)
 {
+	m_hwClipDistance = hwClipDistance;
 	if (m_initialized) {
 		return true;
 	}
@@ -148,6 +149,13 @@ SCP_string VulkanShaderCompiler::buildHeader(vk::ShaderStageFlagBits /*stage*/,
 	// shaderc automatically predefines VULKAN=100 when targeting Vulkan,
 	// so we do NOT define it here — doing so causes a "Macro redefined" error.
 
+	// gl_ClipDistance[] requires the shaderClipDistance device feature. When the
+	// device supports it, use the hardware clip path, otherwise
+	// the shaders fall back to the vClipDist varying (software clipping).
+	if (m_hwClipDistance) {
+		header += "#define USE_HW_CLIP_DISTANCE\n";
+	}
+
 	// Blinn-Phong lighting model (matches OpenGL's opengl_shader_get_header)
 	if (Detail.lighting < 3) {
 		header += "#define FLAG_LIGHT_MODEL_BLINN_PHONG\n";
diff --git a/code/graphics/vulkan/VulkanShaderCompiler.h b/code/graphics/vulkan/VulkanShaderCompiler.h
index 73837ef7b64..5a5046d6a5d 100644
--- a/code/graphics/vulkan/VulkanShaderCompiler.h
+++ b/code/graphics/vulkan/VulkanShaderCompiler.h
@@ -23,6 +23,7 @@ class VulkanShaderCompiler {
 	VulkanShaderCompiler();
 	~VulkanShaderCompiler();
 
+	bool init(bool hwClipDistance);
 	bool init();
 	void shutdown();
 
@@ -69,6 +70,7 @@ class VulkanShaderCompiler {
 
 	std::unique_ptr<VulkanShadercLibrary> m_shaderc;
 	bool m_initialized = false;
+	bool m_hwClipDistance = false;
 };
 
 } // namespace graphics::vulkan
diff --git a/freespace2/SDLGraphicsOperations.cpp b/freespace2/SDLGraphicsOperations.cpp
index 32702c0fa3c..4c5a45c2b71 100644
--- a/freespace2/SDLGraphicsOperations.cpp
+++ b/freespace2/SDLGraphicsOperations.cpp
@@ -328,8 +328,9 @@ std::unique_ptr<os::OpenGLContext> SDLGraphicsOperations::createOpenGLContext(os
 
 	Assertion(ImGui::GetCurrentContext() != nullptr, "Can't use ImGui without a valid context!");
 
-	#ifndef USE_OPENGL_ES
 	ImGui_ImplSDL3_InitForOpenGL(viewport->toSDLWindow(), ctx);
+
+	#ifndef USE_OPENGL_ES
 	ImGui_ImplOpenGL3_Init();
 	#else
 	ImGui_ImplOpenGL3_Init("#version 300 es");
diff --git a/lib/opengl/gl/glad_es/include/glad/glad.h b/lib/opengl/gl/glad_es/include/glad/glad.h
index 550c4ad13bb..5f5cdf5d548 100644
--- a/lib/opengl/gl/glad_es/include/glad/glad.h
+++ b/lib/opengl/gl/glad_es/include/glad/glad.h
@@ -1,6 +1,6 @@
 /*
 
-    OpenGL ES loader generated by glad 0.1.36 on Wed Aug 27 15:16:54 2025.
+    OpenGL ES loader generated by glad 0.1.36 on Sat Jul  4 19:49:32 2026.
 
     Language/Generator: C/C++
     Specification: gl
@@ -10,6 +10,7 @@
         GL_EXT_buffer_storage,
         GL_EXT_clip_cull_distance,
         GL_EXT_color_buffer_float,
+        GL_EXT_depth_clamp,
         GL_EXT_disjoint_timer_query,
         GL_EXT_gpu_shader5,
         GL_EXT_multisampled_render_to_texture,
@@ -27,9 +28,9 @@
     Reproducible: False
 
     Commandline:
-        --profile="core" --api="gles2=3.2" --generator="c" --spec="gl" --extensions="GL_EXT_buffer_storage,GL_EXT_clip_cull_distance,GL_EXT_color_buffer_float,GL_EXT_disjoint_timer_query,GL_EXT_gpu_shader5,GL_EXT_multisampled_render_to_texture,GL_EXT_multisampled_render_to_texture2,GL_EXT_texture_compression_bptc,GL_EXT_texture_compression_s3tc,GL_EXT_texture_filter_anisotropic,GL_EXT_texture_format_BGRA8888,GL_KHR_debug,GL_KHR_texture_compression_astc_ldr,GL_OES_get_program_binary"
+        --profile="core" --api="gles2=3.2" --generator="c" --spec="gl" --extensions="GL_EXT_buffer_storage,GL_EXT_clip_cull_distance,GL_EXT_color_buffer_float,GL_EXT_depth_clamp,GL_EXT_disjoint_timer_query,GL_EXT_gpu_shader5,GL_EXT_multisampled_render_to_texture,GL_EXT_multisampled_render_to_texture2,GL_EXT_texture_compression_bptc,GL_EXT_texture_compression_s3tc,GL_EXT_texture_filter_anisotropic,GL_EXT_texture_format_BGRA8888,GL_KHR_debug,GL_KHR_texture_compression_astc_ldr,GL_OES_get_program_binary"
     Online:
-        https://glad.dav1d.de/#profile=core&language=c&specification=gl&loader=on&api=gles2%3D3.2&extensions=GL_EXT_buffer_storage&extensions=GL_EXT_clip_cull_distance&extensions=GL_EXT_color_buffer_float&extensions=GL_EXT_disjoint_timer_query&extensions=GL_EXT_gpu_shader5&extensions=GL_EXT_multisampled_render_to_texture&extensions=GL_EXT_multisampled_render_to_texture2&extensions=GL_EXT_texture_compression_bptc&extensions=GL_EXT_texture_compression_s3tc&extensions=GL_EXT_texture_filter_anisotropic&extensions=GL_EXT_texture_format_BGRA8888&extensions=GL_KHR_debug&extensions=GL_KHR_texture_compression_astc_ldr&extensions=GL_OES_get_program_binary
+        https://glad.dav1d.de/#profile=core&language=c&specification=gl&loader=on&api=gles2%3D3.2&extensions=GL_EXT_buffer_storage&extensions=GL_EXT_clip_cull_distance&extensions=GL_EXT_color_buffer_float&extensions=GL_EXT_depth_clamp&extensions=GL_EXT_disjoint_timer_query&extensions=GL_EXT_gpu_shader5&extensions=GL_EXT_multisampled_render_to_texture&extensions=GL_EXT_multisampled_render_to_texture2&extensions=GL_EXT_texture_compression_bptc&extensions=GL_EXT_texture_compression_s3tc&extensions=GL_EXT_texture_filter_anisotropic&extensions=GL_EXT_texture_format_BGRA8888&extensions=GL_KHR_debug&extensions=GL_KHR_texture_compression_astc_ldr&extensions=GL_OES_get_program_binary
 */
 
 
@@ -2257,6 +2258,7 @@ GLAPI PFNGLTEXSTORAGE3DMULTISAMPLEPROC glad_glTexStorage3DMultisample;
 #define GL_CLIP_DISTANCE5_EXT 0x3005
 #define GL_CLIP_DISTANCE6_EXT 0x3006
 #define GL_CLIP_DISTANCE7_EXT 0x3007
+#define GL_DEPTH_CLAMP_EXT 0x864F
 #define GL_QUERY_COUNTER_BITS_EXT 0x8864
 #define GL_CURRENT_QUERY_EXT 0x8865
 #define GL_QUERY_RESULT_EXT 0x8866
@@ -2366,6 +2368,10 @@ GLAPI int GLAD_GL_EXT_clip_cull_distance;
 #define GL_EXT_color_buffer_float 1
 GLAPI int GLAD_GL_EXT_color_buffer_float;
 #endif
+#ifndef GL_EXT_depth_clamp
+#define GL_EXT_depth_clamp 1
+GLAPI int GLAD_GL_EXT_depth_clamp;
+#endif
 #ifndef GL_EXT_disjoint_timer_query
 #define GL_EXT_disjoint_timer_query 1
 GLAPI int GLAD_GL_EXT_disjoint_timer_query;
diff --git a/lib/opengl/gl/glad_es/src/glad.c b/lib/opengl/gl/glad_es/src/glad.c
index e7bae0f7860..df24c8490ef 100644
--- a/lib/opengl/gl/glad_es/src/glad.c
+++ b/lib/opengl/gl/glad_es/src/glad.c
@@ -1,6 +1,6 @@
 /*
 
-    OpenGL ES loader generated by glad 0.1.36 on Wed Aug 27 15:16:54 2025.
+    OpenGL ES loader generated by glad 0.1.36 on Sat Jul  4 19:49:32 2026.
 
     Language/Generator: C/C++
     Specification: gl
@@ -10,6 +10,7 @@
         GL_EXT_buffer_storage,
         GL_EXT_clip_cull_distance,
         GL_EXT_color_buffer_float,
+        GL_EXT_depth_clamp,
         GL_EXT_disjoint_timer_query,
         GL_EXT_gpu_shader5,
         GL_EXT_multisampled_render_to_texture,
@@ -27,9 +28,9 @@
     Reproducible: False
 
     Commandline:
-        --profile="core" --api="gles2=3.2" --generator="c" --spec="gl" --extensions="GL_EXT_buffer_storage,GL_EXT_clip_cull_distance,GL_EXT_color_buffer_float,GL_EXT_disjoint_timer_query,GL_EXT_gpu_shader5,GL_EXT_multisampled_render_to_texture,GL_EXT_multisampled_render_to_texture2,GL_EXT_texture_compression_bptc,GL_EXT_texture_compression_s3tc,GL_EXT_texture_filter_anisotropic,GL_EXT_texture_format_BGRA8888,GL_KHR_debug,GL_KHR_texture_compression_astc_ldr,GL_OES_get_program_binary"
+        --profile="core" --api="gles2=3.2" --generator="c" --spec="gl" --extensions="GL_EXT_buffer_storage,GL_EXT_clip_cull_distance,GL_EXT_color_buffer_float,GL_EXT_depth_clamp,GL_EXT_disjoint_timer_query,GL_EXT_gpu_shader5,GL_EXT_multisampled_render_to_texture,GL_EXT_multisampled_render_to_texture2,GL_EXT_texture_compression_bptc,GL_EXT_texture_compression_s3tc,GL_EXT_texture_filter_anisotropic,GL_EXT_texture_format_BGRA8888,GL_KHR_debug,GL_KHR_texture_compression_astc_ldr,GL_OES_get_program_binary"
     Online:
-        https://glad.dav1d.de/#profile=core&language=c&specification=gl&loader=on&api=gles2%3D3.2&extensions=GL_EXT_buffer_storage&extensions=GL_EXT_clip_cull_distance&extensions=GL_EXT_color_buffer_float&extensions=GL_EXT_disjoint_timer_query&extensions=GL_EXT_gpu_shader5&extensions=GL_EXT_multisampled_render_to_texture&extensions=GL_EXT_multisampled_render_to_texture2&extensions=GL_EXT_texture_compression_bptc&extensions=GL_EXT_texture_compression_s3tc&extensions=GL_EXT_texture_filter_anisotropic&extensions=GL_EXT_texture_format_BGRA8888&extensions=GL_KHR_debug&extensions=GL_KHR_texture_compression_astc_ldr&extensions=GL_OES_get_program_binary
+        https://glad.dav1d.de/#profile=core&language=c&specification=gl&loader=on&api=gles2%3D3.2&extensions=GL_EXT_buffer_storage&extensions=GL_EXT_clip_cull_distance&extensions=GL_EXT_color_buffer_float&extensions=GL_EXT_depth_clamp&extensions=GL_EXT_disjoint_timer_query&extensions=GL_EXT_gpu_shader5&extensions=GL_EXT_multisampled_render_to_texture&extensions=GL_EXT_multisampled_render_to_texture2&extensions=GL_EXT_texture_compression_bptc&extensions=GL_EXT_texture_compression_s3tc&extensions=GL_EXT_texture_filter_anisotropic&extensions=GL_EXT_texture_format_BGRA8888&extensions=GL_KHR_debug&extensions=GL_KHR_texture_compression_astc_ldr&extensions=GL_OES_get_program_binary
 */
 
 #include <stdio.h>
@@ -501,6 +502,7 @@ PFNGLWAITSYNCPROC glad_glWaitSync = NULL;
 int GLAD_GL_EXT_buffer_storage = 0;
 int GLAD_GL_EXT_clip_cull_distance = 0;
 int GLAD_GL_EXT_color_buffer_float = 0;
+int GLAD_GL_EXT_depth_clamp = 0;
 int GLAD_GL_EXT_disjoint_timer_query = 0;
 int GLAD_GL_EXT_gpu_shader5 = 0;
 int GLAD_GL_EXT_multisampled_render_to_texture = 0;
@@ -969,6 +971,7 @@ static int find_extensionsGLES2(void) {
 	GLAD_GL_EXT_buffer_storage = has_ext("GL_EXT_buffer_storage");
 	GLAD_GL_EXT_clip_cull_distance = has_ext("GL_EXT_clip_cull_distance");
 	GLAD_GL_EXT_color_buffer_float = has_ext("GL_EXT_color_buffer_float");
+	GLAD_GL_EXT_depth_clamp = has_ext("GL_EXT_depth_clamp");
 	GLAD_GL_EXT_disjoint_timer_query = has_ext("GL_EXT_disjoint_timer_query");
 	GLAD_GL_EXT_gpu_shader5 = has_ext("GL_EXT_gpu_shader5");
 	GLAD_GL_EXT_multisampled_render_to_texture = has_ext("GL_EXT_multisampled_render_to_texture");