86 lines
3.1 KiB
GLSL
86 lines
3.1 KiB
GLSL
// pathfinder/shaders/gles2/ecaa-line.vs.glsl
|
|
//
|
|
// Copyright (c) 2017 The Pathfinder Project Developers.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
|
|
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
|
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
|
|
// option. This file may not be copied, modified, or distributed
|
|
// except according to those terms.
|
|
|
|
//! Implements *edge coverage antialiasing* (ECAA) for straight-line path
|
|
//! segments.
|
|
//!
|
|
//! This shader expects to render to the red channel of a floating point color
|
|
//! buffer. Half precision floating point should be sufficient.
|
|
//!
|
|
//! Use this shader only when *both* of the following are true:
|
|
//!
|
|
//! 1. You are only rendering monochrome paths such as text. (Otherwise,
|
|
//! consider `mcaa-multi`.)
|
|
//!
|
|
//! 2. The paths are relatively small, so overdraw is not a concern.
|
|
//! (Otherwise, consider the MCAA shaders.)
|
|
|
|
precision highp float;
|
|
|
|
uniform mat4 uTransform;
|
|
uniform vec4 uHints;
|
|
uniform ivec2 uFramebufferSize;
|
|
uniform ivec2 uPathBoundsDimensions;
|
|
uniform sampler2D uPathBounds;
|
|
uniform ivec2 uPathTransformSTDimensions;
|
|
uniform sampler2D uPathTransformST;
|
|
uniform ivec2 uPathTransformExtDimensions;
|
|
uniform sampler2D uPathTransformExt;
|
|
uniform vec2 uEmboldenAmount;
|
|
|
|
attribute vec2 aQuadPosition;
|
|
attribute vec2 aLeftPosition;
|
|
attribute vec2 aRightPosition;
|
|
attribute float aPathID;
|
|
attribute float aLeftNormalAngle;
|
|
attribute float aRightNormalAngle;
|
|
|
|
varying vec4 vEndpoints;
|
|
varying float vWinding;
|
|
|
|
void main() {
|
|
vec2 leftPosition = aLeftPosition;
|
|
vec2 rightPosition = aRightPosition;
|
|
int pathID = int(aPathID);
|
|
vec2 leftRightNormalAngles = vec2(aLeftNormalAngle, aRightNormalAngle);
|
|
|
|
vec2 pathTransformExt;
|
|
vec4 pathTransformST = fetchPathAffineTransform(pathTransformExt,
|
|
uPathTransformST,
|
|
uPathTransformSTDimensions,
|
|
uPathTransformExt,
|
|
uPathTransformExtDimensions,
|
|
pathID);
|
|
vec4 bounds = fetchFloat4Data(uPathBounds, pathID, uPathBoundsDimensions);
|
|
|
|
// Transform the points, and compute the position of this vertex.
|
|
vec2 position;
|
|
float winding;
|
|
computeECAAQuadPosition(position,
|
|
winding,
|
|
leftPosition,
|
|
rightPosition,
|
|
aQuadPosition,
|
|
uFramebufferSize,
|
|
pathTransformST,
|
|
pathTransformExt,
|
|
uTransform,
|
|
uHints,
|
|
bounds,
|
|
leftRightNormalAngles,
|
|
uEmboldenAmount);
|
|
|
|
float depth = convertPathIndexToViewportDepthValue(pathID);
|
|
|
|
gl_Position = vec4(position, depth, 1.0);
|
|
vEndpoints = vec4(leftPosition, rightPosition);
|
|
vWinding = winding;
|
|
}
|