ZaStoGram_desktop/Telegram/shaders/incoming_shadow.frag
Ilya Fedin ce36ff3140 [qrhi] Fixed the gl_FragCoord origin difference on OpenGL.
The fragment shaders converted gl_FragCoord.y to the bottom-left based
system of the rectangle uniforms unconditionally, which only holds for
Vulkan, Metal and D3D, where gl_FragCoord.y counts from the top. On
OpenGL it counts from the bottom, so the media viewer and PiP fades,
the content rounding and the incoming call shadow came out mirrored
there. The conversion is now driven by a fragCoordYUp uniform, kept at
offset 8 in every block that needs it.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-11 16:50:35 +03:00

24 lines
686 B
GLSL

#version 450
layout(location = 0) in vec2 v_texcoord;
layout(location = 0) out vec4 fragColor;
layout(binding = 1) uniform sampler2D s_texture;
layout(std140, binding = 0) uniform Params {
vec2 viewport;
// 1.0 when gl_FragCoord.y counts from the bottom (OpenGL).
float fragCoordYUp;
vec3 shadow;
};
void main() {
float fragY = (fragCoordYUp > 0.0)
? gl_FragCoord.y
: (viewport.y - gl_FragCoord.y);
vec4 result = texture(s_texture, v_texcoord);
float shadowCoord = shadow.y - fragY;
float shadowValue = clamp(shadowCoord / shadow.x, 0.0, 1.0);
float shadowShown = shadowValue * shadow.z;
fragColor = vec4(min(result.rgb, vec3(1.0)) * (1.0 - shadowShown), result.a);
}