From 48cf3764626e1ed30450d15e00befb75a4eae329 Mon Sep 17 00:00:00 2001 From: Marshall Mohror Date: Wed, 20 Oct 2021 18:36:06 -0500 Subject: OpenGL: Implement FXAA --- src/video_core/host_shaders/fxaa.frag | 72 +++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 src/video_core/host_shaders/fxaa.frag (limited to 'src/video_core/host_shaders/fxaa.frag') diff --git a/src/video_core/host_shaders/fxaa.frag b/src/video_core/host_shaders/fxaa.frag new file mode 100644 index 000000000..23f910d4c --- /dev/null +++ b/src/video_core/host_shaders/fxaa.frag @@ -0,0 +1,72 @@ +// Adapted from +// https://www.geeks3d.com/20110405/fxaa-fast-approximate-anti-aliasing-demo-glsl-opengl-test-radeon-geforce/3/ + +#version 460 + +#ifdef VULKAN + +#define BINDING_COLOR_TEXTURE 1 + +#else // ^^^ Vulkan ^^^ // vvv OpenGL vvv + +#define BINDING_COLOR_TEXTURE 0 + +#endif + +layout (location = 0) in vec4 posPos; + +layout (location = 0) out vec4 frag_color; + +layout (binding = BINDING_COLOR_TEXTURE) uniform sampler2D input_texture; + +const float FXAA_SPAN_MAX = 8.0; +const float FXAA_REDUCE_MUL = 1.0 / 8.0; +const float FXAA_REDUCE_MIN = 1.0 / 128.0; + +#define FxaaTexLod0(t, p) textureLod(t, p, 0.0) +#define FxaaTexOff(t, p, o) textureLodOffset(t, p, 0.0, o) + +vec3 FxaaPixelShader(vec4 posPos, sampler2D tex) { + + vec3 rgbNW = FxaaTexLod0(tex, posPos.zw).xyz; + vec3 rgbNE = FxaaTexOff(tex, posPos.zw, ivec2(1,0)).xyz; + vec3 rgbSW = FxaaTexOff(tex, posPos.zw, ivec2(0,1)).xyz; + vec3 rgbSE = FxaaTexOff(tex, posPos.zw, ivec2(1,1)).xyz; + vec3 rgbM = FxaaTexLod0(tex, posPos.xy).xyz; +/*---------------------------------------------------------*/ + vec3 luma = vec3(0.299, 0.587, 0.114); + float lumaNW = dot(rgbNW, luma); + float lumaNE = dot(rgbNE, luma); + float lumaSW = dot(rgbSW, luma); + float lumaSE = dot(rgbSE, luma); + float lumaM = dot(rgbM, luma); +/*---------------------------------------------------------*/ + float lumaMin = min(lumaM, min(min(lumaNW, lumaNE), min(lumaSW, lumaSE))); + float lumaMax = max(lumaM, max(max(lumaNW, lumaNE), max(lumaSW, lumaSE))); +/*---------------------------------------------------------*/ + vec2 dir; + dir.x = -((lumaNW + lumaNE) - (lumaSW + lumaSE)); + dir.y = ((lumaNW + lumaSW) - (lumaNE + lumaSE)); +/*---------------------------------------------------------*/ + float dirReduce = max( + (lumaNW + lumaNE + lumaSW + lumaSE) * (0.25 * FXAA_REDUCE_MUL), + FXAA_REDUCE_MIN); + float rcpDirMin = 1.0/(min(abs(dir.x), abs(dir.y)) + dirReduce); + dir = min(vec2( FXAA_SPAN_MAX, FXAA_SPAN_MAX), + max(vec2(-FXAA_SPAN_MAX, -FXAA_SPAN_MAX), + dir * rcpDirMin)) / textureSize(tex, 0); +/*--------------------------------------------------------*/ + vec3 rgbA = (1.0 / 2.0) * ( + FxaaTexLod0(tex, posPos.xy + dir * (1.0 / 3.0 - 0.5)).xyz + + FxaaTexLod0(tex, posPos.xy + dir * (2.0 / 3.0 - 0.5)).xyz); + vec3 rgbB = rgbA * (1.0 / 2.0) + (1.0 / 4.0) * ( + FxaaTexLod0(tex, posPos.xy + dir * (0.0 / 3.0 - 0.5)).xyz + + FxaaTexLod0(tex, posPos.xy + dir * (3.0 / 3.0 - 0.5)).xyz); + float lumaB = dot(rgbB, luma); + if((lumaB < lumaMin) || (lumaB > lumaMax)) return rgbA; + return rgbB; +} + +void main() { + frag_color = vec4(FxaaPixelShader(posPos, input_texture), 1.0); +} -- cgit v1.2.3