feat: extract #define macro constants from C headers in specgen

The spec generation pipeline was losing #define constants because
clang -E preprocessing expanded them before c2ffi could see them.

Fix: parse original (pre-preprocessed) headers directly with regex
to extract #define NAME VALUE patterns. Store in spec as Macros map.

In idiomgen:
- extra_enums values auto-resolve from macros (header is authoritative)
- Unmatched macros generate as untyped constants in constants.go

This auto-extracts 154 EGL, 1819 GLES2, and 624 GLES3 constants from
headers. Examples updated to use package constants instead of local
magic values (EGL_VENDOR, GL_UNSIGNED_SHORT, GL_TIMEOUT_IGNORED, etc).

Author: xaionaro@dx.center

audio/constants.go

@@ -491,13 +491,13 @@ func initEGL(win unsafe.Pointer) error {
 		egl.None,
 	}
 	eglCtx = egl.CreateContext(eglDisp, config, nil, &ctxAttribs[0])
-	if errCode := egl.GetError(); errCode != 0x3000 { // EGL_SUCCESS
+	if errCode := egl.GetError(); errCode != egl.EGL_SUCCESS {
 		return fmt.Errorf("eglCreateContext failed: 0x%x", errCode)
 	}
 	eglHasCtx = true
 
 	eglSurf = egl.CreateWindowSurface(eglDisp, config, egl.EGLNativeWindowType(win), nil)
-	if errCode := egl.GetError(); errCode != 0x3000 { // EGL_SUCCESS
+	if errCode := egl.GetError(); errCode != egl.EGL_SUCCESS {
 		return fmt.Errorf("eglCreateWindowSurface failed: 0x%x", errCode)
 	}
 	eglHasSurf = true

egl/constants.go

@@ -13,20 +13,6 @@ import (
 	"github.com/xaionaro-go/ndk/egl"
 )
 
-// EGL attribute constants not exported by the idiomatic bindings.
-const (
-	eglSamples          egl.Int = 12337
-	eglSampleBuffers    egl.Int = 12338
-	eglMaxPbufferWidth  egl.Int = 12330
-	eglMaxPbufferHeight egl.Int = 12329
-	eglMaxPbufferPixels egl.Int = 12331
-	eglNativeRenderable egl.Int = 12346
-	eglNativeVisualId   egl.Int = 12349
-	eglConformant       egl.Int = 12354
-	eglConfigCaveat     egl.Int = 12327
-	eglPixmapBit        egl.Int = 2
-)
-
 func fatal(msg string) {
 	fmt.Fprintf(os.Stderr, "error: %s (EGL error 0x%04X)\n", msg, egl.GetError())
 	os.Exit(1)
@@ -88,17 +74,17 @@ func main() {
 		{"Alpha Size", egl.AlphaSize},
 		{"Depth Size", egl.DepthSize},
 		{"Stencil Size", egl.StencilSize},
-		{"Samples", eglSamples},
-		{"Sample Buffers", eglSampleBuffers},
-		{"Max Pbuffer Width", eglMaxPbufferWidth},
-		{"Max Pbuffer Height", eglMaxPbufferHeight},
-		{"Max Pbuffer Pixels", eglMaxPbufferPixels},
-		{"Native Renderable", eglNativeRenderable},
-		{"Native Visual ID", eglNativeVisualId},
+		{"Samples", egl.EGL_SAMPLES},
+		{"Sample Buffers", egl.EGL_SAMPLE_BUFFERS},
+		{"Max Pbuffer Width", egl.EGL_MAX_PBUFFER_WIDTH},
+		{"Max Pbuffer Height", egl.EGL_MAX_PBUFFER_HEIGHT},
+		{"Max Pbuffer Pixels", egl.EGL_MAX_PBUFFER_PIXELS},
+		{"Native Renderable", egl.EGL_NATIVE_RENDERABLE},
+		{"Native Visual ID", egl.EGL_NATIVE_VISUAL_ID},
 		{"Surface Type (bitmask)", egl.SurfaceType},
 		{"Renderable Type (bitmask)", egl.RenderableType},
-		{"Conformant (bitmask)", eglConformant},
-		{"Config Caveat", eglConfigCaveat},
+		{"Conformant (bitmask)", egl.EGL_CONFORMANT},
+		{"Config Caveat", egl.EGL_CONFIG_CAVEAT},
 	}
 
 	fmt.Println("Config attributes:")
@@ -112,7 +98,7 @@ func main() {
 	surfType := getAttrib(display, config, egl.SurfaceType)
 	printFlag("  Window", surfType, egl.WindowBit)
 	printFlag("  Pbuffer", surfType, egl.PbufferBit)
-	printFlag("  Pixmap", surfType, eglPixmapBit)
+	printFlag("  Pixmap", surfType, egl.EGL_PIXMAP_BIT)
 
 	fmt.Println("Renderable type flags:")
 	rendType := getAttrib(display, config, egl.RenderableType)

examples/camera/display/main.go

@@ -12,14 +12,6 @@ import (
 	"github.com/xaionaro-go/ndk/egl"
 )
 
-// Standard EGL query-string name constants (not exported by the bindings).
-const (
-	eglVendor     egl.Int = 0x3053
-	eglVersion    egl.Int = 0x3054
-	eglExtensions egl.Int = 0x3055
-	eglClientAPIs egl.Int = 0x308D
-)
-
 func fatal(msg string) {
 	fmt.Fprintf(os.Stderr, "error: %s (EGL error 0x%04X)\n", msg, egl.GetError())
 	os.Exit(1)
@@ -46,10 +38,10 @@ func main() {
 		label string
 		name  egl.Int
 	}{
-		{"Vendor", eglVendor},
-		{"Version", eglVersion},
-		{"Client APIs", eglClientAPIs},
-		{"Extensions", eglExtensions},
+		{"Vendor", egl.EGL_VENDOR},
+		{"Version", egl.EGL_VERSION},
+		{"Client APIs", egl.EGL_CLIENT_APIS},
+		{"Extensions", egl.EGL_EXTENSIONS},
 	}
 	for _, q := range queries {
 		s := egl.QueryString(display, q.name)

examples/egl/config-query/main.go

@@ -19,14 +19,6 @@ import (
 	"github.com/xaionaro-go/ndk/gles2"
 )
 
-// EGL query-string name constants (not exported by the idiomatic bindings).
-const (
-	eglVendor     egl.Int = 0x3053
-	eglVersion    egl.Int = 0x3054
-	eglExtensions egl.Int = 0x3055
-	eglClientAPIs egl.Int = 0x308D
-)
-
 // Pbuffer dimensions.
 const (
 	pbufWidth  = 64
@@ -121,10 +113,10 @@ func main() {
 		label string
 		name  egl.Int
 	}{
-		{"Vendor", eglVendor},
-		{"Version", eglVersion},
-		{"Client APIs", eglClientAPIs},
-		{"Extensions", eglExtensions},
+		{"Vendor", egl.EGL_VENDOR},
+		{"Version", egl.EGL_VERSION},
+		{"Client APIs", egl.EGL_CLIENT_APIS},
+		{"Extensions", egl.EGL_EXTENSIONS},
 	}
 	fmt.Println("\nEGL display info:")
 	for _, q := range queries {

examples/egl/initialize/main.go

@@ -25,8 +25,6 @@ import (
 	"github.com/xaionaro-go/ndk/gles2"
 )
 
-// GL_UNSIGNED_SHORT is not in the generated enum set.
-const glUnsignedShort gles2.Enum = 0x1403
 
 func fatal(msg string) {
 	fmt.Fprintf(os.Stderr, "fatal: %s (EGL error 0x%04X)\n", msg, egl.GetError())
@@ -361,7 +359,7 @@ func main() {
 	gles2.EnableVertexAttribArray(gles2.GLuint(texLoc2))
 	gles2.VertexAttribPointer(gles2.GLuint(texLoc2), 2, gles2.Float, gles2.Boolean(gles2.False), stride, texOffset)
 
-	gles2.DrawElements(gles2.Triangles, 6, glUnsignedShort, nil)
+	gles2.DrawElements(gles2.Triangles, 6, gles2.GL_UNSIGNED_SHORT, nil)
 	checkGL("pass 2 render")
 
 	gles2.DisableVertexAttribArray(gles2.GLuint(posLoc2))

examples/egl/offscreen-render/main.go

@@ -21,8 +21,6 @@ import (
 	"github.com/xaionaro-go/ndk/gles2"
 )
 
-// GL_UNSIGNED_SHORT is not in the generated enum set.
-const glUnsignedShort gles2.Enum = 0x1403
 
 func fatal(msg string) {
 	fmt.Fprintf(os.Stderr, "fatal: %s (EGL error 0x%04X)\n", msg, egl.GetError())
@@ -305,7 +303,7 @@ func main() {
 		texOffset,
 	)
 
-	gles2.DrawElements(gles2.Triangles, 6, glUnsignedShort, nil)
+	gles2.DrawElements(gles2.Triangles, 6, gles2.GL_UNSIGNED_SHORT, nil)
 	checkGL("DrawElements")
 
 	gles2.DisableVertexAttribArray(gles2.GLuint(posLoc))

examples/gles2/framebuffer/main.go

@@ -22,8 +22,6 @@ import (
 	"github.com/xaionaro-go/ndk/gles3"
 )
 
-// GL_TIMEOUT_IGNORED is defined as 0xFFFFFFFFFFFFFFFF in the spec.
-const glTimeoutIgnored = uint64(0xFFFFFFFFFFFFFFFF)
 
 var triVertices = [...]float32{
 	0.0, 0.5,
@@ -85,7 +83,7 @@ func main() {
 	// SYNC_FLUSH_COMMANDS_BIT tells the driver to flush if the sync is not
 	// already signalled, which avoids a potential deadlock when the command
 	// queue has not been flushed yet.
-	result := gles3.ClientWaitSync(sync, gles3.SyncFlushCommandsBit, gles3.GLuint64(glTimeoutIgnored))
+	result := gles3.ClientWaitSync(sync, gles3.SyncFlushCommandsBit, gles3.GLuint64(gles3.GL_TIMEOUT_IGNORED))
 	switch result {
 	case gles3.AlreadySignaled:
 		log.Println("ClientWaitSync: already signalled (GPU was fast)")

examples/gles2/texture/main.go

@@ -23,11 +23,6 @@ import (
 	"github.com/xaionaro-go/ndk/gles3"
 )
 
-// GL constants for rasterizer discard and map read.
-const (
-	glRasterizerDiscard gles2.Enum       = 0x8C89
-	glMapReadBit        gles3.GLbitfield = 0x0001
-)
 
 // Input positions: three 2D points.
 var inputPositions = [...]float32{
@@ -109,13 +104,13 @@ func main() {
 	gles2.UseProgram(program)
 
 	// Disable rasterization: we only care about the vertex shader output.
-	gles2.Enable(glRasterizerDiscard)
+	gles2.Enable(gles3.GL_RASTERIZER_DISCARD)
 
 	gles3.BeginTransformFeedback(gles3.GLenum(gles2.Points))
 	gles2.DrawArrays(gles2.Points, 0, gles2.GLsizei(vertexCount))
 	gles3.EndTransformFeedback()
 
-	gles2.Disable(glRasterizerDiscard)
+	gles2.Disable(gles3.GL_RASTERIZER_DISCARD)
 	checkGLError("after transform feedback")
 
 	// --- Read back captured data ---
@@ -130,7 +125,7 @@ func main() {
 		gles3.TransformFeedbackBuffer,
 		0,
 		gles3.GLsizeiptr(feedbackBufSize),
-		glMapReadBit,
+		gles3.GL_MAP_READ_BIT,
 	)
 	if ptr == nil {
 		log.Fatal("MapBufferRange returned nil")