Document more shader parameters

demo/client/src/xcaa-strategy.ts

@@ -764,26 +764,16 @@ export class ECAAStrategy extends XCAAStrategy {
 
             if (renderer.meshData[0].segmentLineNormals.byteLength > 0) {
                 gl.bindBuffer(gl.ARRAY_BUFFER, lineNormalsBuffer);
-                gl.vertexAttribPointer(attributes.aLeftNormalAngle,
-                                       1,
+                gl.vertexAttribPointer(attributes.aNormalAngles,
+                                       2,
                                        gl.FLOAT,
                                        false,
                                        FLOAT32_SIZE * 2,
                                        0);
-                gl.vertexAttribPointer(attributes.aRightNormalAngle,
-                                       1,
-                                       gl.FLOAT,
-                                       false,
-                                       FLOAT32_SIZE * 2,
-                                       FLOAT32_SIZE);
-
-                gl.enableVertexAttribArray(attributes.aLeftNormalAngle);
-                gl.enableVertexAttribArray(attributes.aRightNormalAngle);
+                gl.enableVertexAttribArray(attributes.aNormalAngles);
 
                 renderContext.instancedArraysExt
-                             .vertexAttribDivisorANGLE(attributes.aLeftNormalAngle, 1);
-                renderContext.instancedArraysExt
-                             .vertexAttribDivisorANGLE(attributes.aRightNormalAngle, 1);
+                             .vertexAttribDivisorANGLE(attributes.aNormalAngles, 1);
             }
 
             gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, renderContext.quadElementsBuffer);

shaders/gles2/blit-gamma.fs.glsl

@@ -14,10 +14,8 @@ precision mediump float;
 
 /// The source texture to blit.
 uniform sampler2D uSource;
-
 /// The approximate background color, in linear RGB.
 uniform vec3 uBGColor;
-
 /// The gamma LUT.
 uniform sampler2D uGammaLUT;
 

shaders/gles2/demo-3d-distant-glyph.fs.glsl

@@ -12,9 +12,12 @@
 
 precision highp float;
 
+/// The color of the font.
 uniform vec4 uColor;
+/// The cached glyph atlas.
 uniform sampler2D uAtlas;
 
+/// The texture coordinate.
 varying vec2 vTexCoord;
 
 void main() {

shaders/gles2/demo-3d-distant-glyph.vs.glsl

@@ -19,9 +19,12 @@ uniform vec4 uGlyphTexCoords;
 /// The size of the glyph in local coordinates.
 uniform vec2 uGlyphSize;
 
+/// The abstract quad position: (0.0, 0.0) to (1.0, 1.0).
 attribute vec2 aQuadPosition;
+// The world-space 2D position of this vertex.
 attribute vec2 aPosition;
 
+/// The texture coordinate.
 varying vec2 vTexCoord;
 
 void main() {

shaders/gles2/demo-3d-monument.fs.glsl

@@ -12,12 +12,17 @@
 
 precision mediump float;
 
+/// The 3D position of the light.
 uniform vec3 uLightPosition;
+/// The ambient color of the light.
 uniform vec3 uAmbientColor;
+/// The diffuse color of the light.
 uniform vec3 uDiffuseColor;
+/// The Phong specular color of the light.
 uniform vec3 uSpecularColor;
+/// The Phong albedo exponent.
 uniform float uShininess;
-
+/// The normal of these vertices.
 uniform vec3 uNormal;
 
 varying vec3 vPosition;

shaders/gles2/demo-3d-monument.vs.glsl

@@ -17,8 +17,10 @@ uniform mat4 uProjection;
 /// The 3D modelview matrix.
 uniform mat4 uModelview;
 
+/// The 3D vertex position.
 attribute vec3 aPosition;
 
+/// The 3D vertex position.
 varying vec3 vPosition;
 
 void main() {

shaders/gles2/direct-3d-curve.vs.glsl

@@ -16,23 +16,39 @@
 
 precision highp float;
 
+/// A 3D transform to be applied to all points.
 uniform mat4 uTransform;
-uniform vec2 uEmboldenAmount;
-uniform ivec2 uPathColorsDimensions;
-uniform sampler2D uPathColors;
+/// The size of the path transform buffer texture in texels.
 uniform ivec2 uPathTransformSTDimensions;
+/// The path transform buffer texture, one dilation per path ID.
 uniform sampler2D uPathTransformST;
+/// The size of the extra path transform factors buffer texture in texels.
 uniform ivec2 uPathTransformExtDimensions;
+/// The extra path transform factors buffer texture, packed two path transforms per texel.
 uniform sampler2D uPathTransformExt;
+/// The size of the path colors buffer texture in texels.
+uniform ivec2 uPathColorsDimensions;
+/// The path colors buffer texture, one color per path ID.
+uniform sampler2D uPathColors;
+/// The amount of faux-bold to apply, in local path units.
+uniform vec2 uEmboldenAmount;
 
+/// The 2D position of this point.
 attribute vec2 aPosition;
+/// The abstract Loop-Blinn texture coordinate for this point.
 attribute vec2 aTexCoord;
+/// The path ID, starting from 1.
 attribute float aPathID;
+/// Specifies whether this is a concave or convex curve.
 attribute float aSign;
+/// The angle of the 2D normal for this point.
 attribute float aNormalAngle;
 
+/// The fill color of this path.
 varying vec4 vColor;
+/// The outgoing abstract Loop-Blinn texture coordinate.
 varying vec2 vTexCoord;
+/// Specifies whether this is a concave or convex curve.
 varying float vSign;
 
 void main() {

shaders/gles2/direct-curve.fs.glsl

@@ -21,8 +21,11 @@
 
 precision highp float;
 
+/// The fill color of this path.
 varying vec4 vColor;
+/// The abstract Loop-Blinn texture coordinate.
 varying vec2 vTexCoord;
+/// Specifies whether this is a concave or convex curve.
 varying float vSign;
 
 void main() {

shaders/gles2/direct-curve.vs.glsl

@@ -40,14 +40,22 @@ uniform sampler2D uPathTransformExt;
 /// The amount of faux-bold to apply, in local path units.
 uniform vec2 uEmboldenAmount;
 
+/// The 2D position of this point.
 attribute vec2 aPosition;
+/// The abstract Loop-Blinn texture coordinate for this point.
 attribute vec2 aTexCoord;
+/// The path ID, starting from 1.
 attribute float aPathID;
+/// Specifies whether this is a concave or convex curve.
 attribute float aSign;
+/// The angle of the 2D normal for this point.
 attribute float aNormalAngle;
 
+/// The fill color of this path.
 varying vec4 vColor;
+/// The outgoing abstract Loop-Blinn texture coordinate.
 varying vec2 vTexCoord;
+/// Specifies whether this is a concave or convex curve.
 varying float vSign;
 
 void main() {

shaders/gles2/direct-interior.fs.glsl

@@ -16,6 +16,7 @@
 
 precision highp float;
 
+/// The color of this path.
 varying vec4 vColor;
 
 void main() {

shaders/gles2/direct-interior.vs.glsl

@@ -39,6 +39,7 @@ attribute vec2 aPosition;
 attribute float aPathID;
 attribute float aNormalAngle;
 
+/// The color of this path.
 varying vec4 vColor;
 
 void main() {

shaders/gles2/ecaa-curve.vs.glsl

@@ -26,7 +26,7 @@
 
 precision highp float;
 
-/// A 3D transform to be applied to the object.
+/// A 3D transform to be applied to all points.
 uniform mat4 uTransform;
 /// Vertical snapping positions.
 uniform vec4 uHints;
@@ -47,11 +47,17 @@ uniform sampler2D uPathTransformExt;
 /// The amount of faux-bold to apply, in local path units.
 uniform vec2 uEmboldenAmount;
 
+/// The abstract quad position: (0.0, 0.0) to (1.0, 1.0).
 attribute vec2 aQuadPosition;
+/// The position of the left endpoint.
 attribute vec2 aLeftPosition;
+/// The position of the control point.
 attribute vec2 aControlPointPosition;
+/// The position of the right endpoint.
 attribute vec2 aRightPosition;
+/// The path ID (starting from 1).
 attribute float aPathID;
+/// The normal angles of the left endpoint, control point, and right endpoint, respectively.
 attribute vec3 aNormalAngles;
 
 varying vec4 vEndpoints;

shaders/gles2/ecaa-line.vs.glsl

@@ -45,12 +45,16 @@ uniform sampler2D uPathTransformExt;
 /// The amount of faux-bold to apply, in local path units.
 uniform vec2 uEmboldenAmount;
 
+/// The abstract quad position: (0.0, 0.0) to (1.0, 1.0).
 attribute vec2 aQuadPosition;
+/// The position of the left endpoint.
 attribute vec2 aLeftPosition;
+/// The position of the right endpoint.
 attribute vec2 aRightPosition;
+/// The path ID (starting from 1).
 attribute float aPathID;
-attribute float aLeftNormalAngle;
-attribute float aRightNormalAngle;
+/// The normal angles of the left endpoint and right endpoint, respectively.
+attribute vec2 aNormalAngles;
 
 varying vec4 vEndpoints;
 varying float vWinding;
@@ -59,7 +63,7 @@ void main() {
     vec2 leftPosition = aLeftPosition;
     vec2 rightPosition = aRightPosition;
     int pathID = int(aPathID);
-    vec2 leftRightNormalAngles = vec2(aLeftNormalAngle, aRightNormalAngle);
+    vec2 leftRightNormalAngles = aNormalAngles;
 
     vec2 pathTransformExt;
     vec4 pathTransformST = fetchPathAffineTransform(pathTransformExt,

shaders/gles2/ecaa-transformed-curve.vs.glsl

@@ -56,11 +56,17 @@ uniform vec2 uEmboldenAmount;
 /// an identical draw call with this value set to 1.
 uniform int uPassIndex;
 
+/// The abstract quad position: (0.0, 0.0) to (1.0, 1.0).
 attribute vec2 aQuadPosition;
+/// The position of the left endpoint.
 attribute vec2 aLeftPosition;
+/// The position of the control point.
 attribute vec2 aControlPointPosition;
+/// The position of the right endpoint.
 attribute vec2 aRightPosition;
+/// The path ID (starting from 1).
 attribute float aPathID;
+/// The normal angles of the left endpoint, control point, and right endpoint, respectively.
 attribute vec3 aNormalAngles;
 
 varying vec4 vEndpoints;

shaders/gles2/mcaa.fs.glsl

@@ -25,6 +25,9 @@
 
 precision highp float;
 
+/// True if multiple colors are being rendered; false otherwise.
+///
+/// If this is true, then points will be snapped to the nearest pixel.
 uniform bool uMulticolor;
 
 varying vec4 vUpperEndpoints;

shaders/gles2/ssaa-subpixel-resolve.fs.glsl

@@ -14,7 +14,9 @@
 
 precision mediump float;
 
+/// The alpha coverage texture.
 uniform sampler2D uSource;
+/// The dimensions of the alpha coverage texture, in texels.
 uniform ivec2 uSourceDimensions;
 
 varying vec2 vTexCoord;

shaders/gles2/xcaa-mono-resolve.fs.glsl

@@ -12,8 +12,11 @@
 
 precision mediump float;
 
+/// The background color of the monochrome path.
 uniform vec4 uBGColor;
+/// The foreground color of the monochrome path.
 uniform vec4 uFGColor;
+/// The alpha coverage texture.
 uniform sampler2D uAAAlpha;
 
 varying vec2 vTexCoord;

shaders/gles2/xcaa-mono-resolve.vs.glsl

@@ -17,7 +17,9 @@ uniform vec4 uTransformST;
 /// A fixed pair of factors to be applied to the texture coordinates.
 uniform vec2 uTexScale;
 
+/// The abstract quad position: (0.0, 0.0) to (1.0, 1.0).
 attribute vec2 aPosition;
+/// The texture coordinates: (0.0, 0.0) to (1.0, 1.0).
 attribute vec2 aTexCoord;
 
 varying vec2 vTexCoord;

shaders/gles2/xcaa-mono-subpixel-resolve.fs.glsl

@@ -14,9 +14,13 @@
 
 precision mediump float;
 
+/// The background color of the monochrome path.
 uniform vec4 uBGColor;
+/// The foreground color of the monochrome path.
 uniform vec4 uFGColor;
+/// The alpha coverage texture.
 uniform sampler2D uAAAlpha;
+/// The dimensions of the alpha coverage texture, in texels.
 uniform ivec2 uAAAlphaDimensions;
 
 varying vec2 vTexCoord;

shaders/gles2/xcaa-mono-subpixel-resolve.vs.glsl

@@ -19,7 +19,9 @@ uniform vec4 uTransformST;
 /// A fixed pair of factors to be applied to the texture coordinates.
 uniform vec2 uTexScale;
 
+/// The abstract quad position: (0.0, 0.0) to (1.0, 1.0).
 attribute vec2 aPosition;
+/// The texture coordinates: (0.0, 0.0) to (1.0, 1.0).
 attribute vec2 aTexCoord;
 
 varying vec2 vTexCoord;