Files
gio-patched/gpu/shaders/stencil.vert
T
Viktor cfb9565895 gpu: reintroduce reuse of offset-only stenciling
Reintroduce support for offset in stencil vertex so we can reuse
cached values if the only difference in transform is offset. Split
current transform into a pure-offset part and the rest and use
only the complex part as cache key.

Signed-off-by: Viktor <viktor.ogeman@gmail.com>
2020-06-21 11:20:36 +02:00

54 lines
1.1 KiB
GLSL

#version 310 es
// SPDX-License-Identifier: Unlicense OR MIT
precision highp float;
layout(binding = 0) uniform Block {
vec4 transform;
vec2 pathOffset;
};
layout(location=0) in float corner;
layout(location=1) in float maxy;
layout(location=2) in vec2 from;
layout(location=3) in vec2 ctrl;
layout(location=4) in vec2 to;
layout(location=0) out vec2 vFrom;
layout(location=1) out vec2 vCtrl;
layout(location=2) out vec2 vTo;
void main() {
// Add a one pixel overlap so curve quads cover their
// entire curves. Could use conservative rasterization
// if available.
vec2 from = from + pathOffset;
vec2 ctrl = ctrl + pathOffset;
vec2 to = to + pathOffset;
float maxy = maxy + pathOffset.y;
vec2 pos;
float c = corner;
if (c >= 0.375) {
// North.
c -= 0.5;
pos.y = maxy + 1.0;
} else {
// South.
pos.y = min(min(from.y, ctrl.y), to.y) - 1.0;
}
if (c >= 0.125) {
// East.
pos.x = max(max(from.x, ctrl.x), to.x)+1.0;
} else {
// West.
pos.x = min(min(from.x, ctrl.x), to.x)-1.0;
}
vFrom = from-pos;
vCtrl = ctrl-pos;
vTo = to-pos;
pos = pos*transform.xy + transform.zw;
gl_Position = vec4(pos, 1, 1);
}