pathfinder/shaders/gles2/ecaa-cover.vs.glsl

66 lines
3.0 KiB
GLSL

// pathfinder/shaders/gles2/ecaa-cover.vs.glsl
//
// Copyright (c) 2017 Mozilla Foundation
precision highp float;
uniform mat4 uTransform;
uniform ivec2 uFramebufferSize;
uniform ivec2 uBVertexPositionDimensions;
uniform ivec2 uBVertexPathIDDimensions;
uniform sampler2D uBVertexPosition;
uniform sampler2D uBVertexPathID;
attribute vec2 aQuadPosition;
attribute vec4 aUpperPointIndices;
attribute vec4 aLowerPointIndices;
varying vec2 vHorizontalExtents;
void main() {
// Fetch B-vertex positions.
// FIXME(pcwalton): This could be slightly optimized to fetch fewer positions.
ivec4 pointIndices = ivec4(unpackUInt32Attribute(aUpperPointIndices.xy),
unpackUInt32Attribute(aUpperPointIndices.zw),
unpackUInt32Attribute(aLowerPointIndices.xy),
unpackUInt32Attribute(aLowerPointIndices.zw));
vec2 upperLeftPosition = fetchFloat2Data(uBVertexPosition,
pointIndices.x,
uBVertexPositionDimensions);
vec2 upperRightPosition = fetchFloat2Data(uBVertexPosition,
pointIndices.y,
uBVertexPositionDimensions);
vec2 lowerLeftPosition = fetchFloat2Data(uBVertexPosition,
pointIndices.z,
uBVertexPositionDimensions);
vec2 lowerRightPosition = fetchFloat2Data(uBVertexPosition,
pointIndices.w,
uBVertexPositionDimensions);
upperLeftPosition = transformVertexPosition(upperLeftPosition, uTransform);
upperRightPosition = transformVertexPosition(upperRightPosition, uTransform);
lowerLeftPosition = transformVertexPosition(lowerLeftPosition, uTransform);
lowerRightPosition = transformVertexPosition(lowerRightPosition, uTransform);
vec4 extents = vec4(min(upperLeftPosition.x, lowerLeftPosition.x),
min(min(upperLeftPosition.y, upperRightPosition.y),
min(lowerLeftPosition.y, lowerRightPosition.y)),
max(upperRightPosition.x, lowerRightPosition.x),
max(max(upperLeftPosition.y, upperRightPosition.y),
max(lowerLeftPosition.y, lowerRightPosition.y)));
vec4 roundedExtents = vec4(floor(extents.xy), ceil(extents.zw));
int pathID = fetchUInt16Data(uBVertexPathID, pointIndices.x, uBVertexPathIDDimensions);
// FIXME(pcwalton): Use a separate VBO for this.
vec2 quadPosition = (aQuadPosition + 1.0) * 0.5;
vec2 position = mix(roundedExtents.xy, roundedExtents.zw, quadPosition);
position = convertScreenToClipSpace(position, uFramebufferSize);
float depth = convertPathIndexToDepthValue(pathID);
gl_Position = vec4(position, depth, 1.0);
vHorizontalExtents = extents.xz;
}