updated single colour pipelines to add set_colour method

Author: jmacey

src/ncca/ngl/webgpu/line_pipeline.py

@@ -3,7 +3,7 @@
 Handles line rendering with customizable color and projection.
 """
 
-from typing import Optional
+from typing import Optional, Tuple
 
 import numpy as np
 import wgpu
@@ -101,9 +101,11 @@ def __init__(
 
     def get_dtype(self) -> np.dtype:
         """Get the data type of the pipeline."""
-        return np.dtype([
-            ("MVP", "float32", (4, 4)),
-        ])
+        return np.dtype(
+            [
+                ("MVP", "float32", (4, 4)),
+            ]
+        )
 
     def _get_shader_code(self) -> str:
         """Get the WGSL shader code for this pipeline."""
@@ -193,7 +195,9 @@ def update_uniforms(self, **kwargs) -> None:
         if "mvp" in kwargs and kwargs["mvp"] is not None:
             self.uniform_data["MVP"] = kwargs["mvp"]
 
-        self.device.queue.write_buffer(self.uniform_buffer, 0, self.uniform_data.tobytes())
+        self.device.queue.write_buffer(
+            self.uniform_buffer, 0, self.uniform_data.tobytes()
+        )
 
     def render(self, render_pass: wgpu.GPURenderPassEncoder, **kwargs) -> None:
         """
@@ -247,9 +251,10 @@ def __init__(
         msaa_sample_count: int = 4,
         stride: int = 0,
         topology: wgpu.PrimitiveTopology = wgpu.PrimitiveTopology.line_list,
+        colour: Tuple[float, float, float] = (1.0, 1.0, 1.0),
     ):
         """
-        Initialize the line rendering pipeline.
+        Initialize line rendering pipeline.
 
         Args:
             device: WebGPU device
@@ -258,10 +263,12 @@ def __init__(
             msaa_sample_count: Number of MSAA samples
             stride: The stride of the vertex buffer. If 0, it is inferred from data_type.
             topology: Primitive topology (line_list or line_strip)
+            colour: RGB color tuple for lines (default white)
         """
         # Pipeline-specific buffer tracking
         self.vertex_buffer: Optional[wgpu.GPUBuffer] = None
         self.num_vertices: int = 0
+        self._colour = np.array(colour, dtype=np.float32)
 
         super().__init__(
             device=device,
@@ -275,9 +282,13 @@ def __init__(
 
     def get_dtype(self) -> np.dtype:
         """Get the data type of the pipeline."""
-        return np.dtype([
-            ("MVP", "float32", (4, 4)),
-        ])
+        return np.dtype(
+            [
+                ("MVP", "float32", (4, 4)),
+                ("Colour", "float32", 3),
+                ("padding", "float32", 1),
+            ]
+        )
 
     def _get_shader_code(self) -> str:
         """Get the WGSL shader code for this pipeline."""
@@ -335,11 +346,35 @@ def update_uniforms(self, **kwargs) -> None:
         Args:
             **kwargs: Pipeline-specific uniform parameters
                 - mvp: 4x4 projection matrix
+                - colour: RGB color tuple
         """
         if "mvp" in kwargs and kwargs["mvp"] is not None:
             self.uniform_data["MVP"] = kwargs["mvp"]
 
-        self.device.queue.write_buffer(self.uniform_buffer, 0, self.uniform_data.tobytes())
+        if "colour" in kwargs and kwargs["colour"] is not None:
+            colour = np.array(kwargs["colour"], dtype=np.float32)
+            if colour.shape == (3,):
+                self.uniform_data["Colour"] = colour
+                self._colour = colour
+
+        self.device.queue.write_buffer(
+            self.uniform_buffer, 0, self.uniform_data.tobytes()
+        )
+
+    def set_color(self, colour: Tuple[float, float, float]) -> None:
+        """
+        Set the color for the lines.
+
+        Args:
+            colour: RGB color tuple
+        """
+        colour_array = np.array(colour, dtype=np.float32)
+        if colour_array.shape == (3,):
+            self.uniform_data["Colour"] = colour_array
+            self._colour = colour_array
+            self.device.queue.write_buffer(
+                self.uniform_buffer, 0, self.uniform_data.tobytes()
+            )
 
     def render(self, render_pass: wgpu.GPURenderPassEncoder, **kwargs) -> None:
         """

src/ncca/ngl/webgpu/pipeline_shaders.py

@@ -295,6 +295,8 @@
 // LineShader.wgsl
 struct Uniforms {
     MVP: mat4x4<f32>,
+    Colour: vec3<f32>,
+    padding: f32,
 };
 
 @binding(0) @group(0) var<uniform> uniforms: Uniforms;
@@ -306,7 +308,7 @@
 
 @fragment
 fn fragment_main() -> @location(0) vec4<f32> {
-    return vec4<f32>(1.0, 1.0, 1.0, 1.0); // Grey color for grid lines
+    return vec4<f32>(uniforms.Colour, 1.0);
 }
 """
 

tests/test_triangle_pipeline_coverage.py

@@ -87,6 +87,43 @@ def test_triangle_pipeline_single_colour_color_functionality(webgpu_device):
     )
 
 
+def test_line_pipeline_single_colour_color_functionality(webgpu_device):
+    """Test LinePipelineSingleColour color setting functionality."""
+    from ncca.ngl.webgpu.line_pipeline import LinePipelineSingleColour
+
+    # Test default color (white)
+    pipeline = LinePipelineSingleColour(webgpu_device)
+    assert np.array_equal(pipeline._colour, np.array([1.0, 1.0, 1.0], dtype=np.float32))
+
+    # Test setting color via constructor
+    red_color = (1.0, 0.0, 0.0)
+    pipeline_red = LinePipelineSingleColour(webgpu_device, colour=red_color)
+    assert np.array_equal(pipeline_red._colour, np.array(red_color, dtype=np.float32))
+
+    # Test setting color via update_uniforms
+    green_color = (0.0, 1.0, 0.0)
+    pipeline.update_uniforms(colour=green_color)
+    assert np.array_equal(pipeline._colour, np.array(green_color, dtype=np.float32))
+
+    # Test setting color via set_color method
+    blue_color = (0.0, 0.0, 1.0)
+    pipeline.set_color(blue_color)
+    assert np.array_equal(pipeline._colour, np.array(blue_color, dtype=np.float32))
+
+    # Test uniform buffer structure includes color
+    dtype = pipeline.get_dtype()
+    assert "Colour" in dtype.names
+    colour_field = dtype.fields["Colour"]
+    assert colour_field[0].shape == (3,)  # 3 components
+
+    # Test uniform data gets updated
+    orange_color = (1.0, 0.5, 0.0)
+    pipeline.update_uniforms(colour=orange_color)
+    assert np.array_equal(
+        pipeline.uniform_data["Colour"], np.array(orange_color, dtype=np.float32)
+    )
+
+
 def test_triangle_pipeline_multi_colour_color_processing_tuple_result(webgpu_device):
     """Test multi-colour pipeline when color processing returns tuple to hit lines 240-243."""
     pipeline = TrianglePipelineMultiColour(webgpu_device)