1 files changed, 70 insertions, 0 deletions
diff --git a/src/video_core/host_shaders/present_gaussian.frag b/src/video_core/host_shaders/present_gaussian.frag
new file mode 100644
index 000000000..66fed3238
--- /dev/null
+++ b/src/video_core/host_shaders/present_gaussian.frag
@@ -0,0 +1,70 @@
+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+// Code adapted from the following sources:
+// - https://learnopengl.com/Advanced-Lighting/Bloom
+// - https://www.rastergrid.com/blog/2010/09/efficient-gaussian-blur-with-linear-sampling/
+
+#version 460 core
+
+#ifdef VULKAN
+
+#define BINDING_COLOR_TEXTURE 1
+
+#else // ^^^ Vulkan ^^^ // vvv OpenGL vvv
+
+#define BINDING_COLOR_TEXTURE 0
+
+#endif
+
+layout(location = 0) in vec2 frag_tex_coord;
+
+layout(location = 0) out vec4 color;
+
+layout(binding = BINDING_COLOR_TEXTURE) uniform sampler2D color_texture;
+
+const float offset[3] = float[](0.0, 1.3846153846, 3.2307692308);
+const float weight[3] = float[](0.2270270270, 0.3162162162, 0.0702702703);
+
+vec4 blurVertical(sampler2D textureSampler, vec2 coord, vec2 norm) {
+    vec4 result = vec4(0.0f);
+    for (int i = 1; i < 3; i++) {
+        result += texture(textureSampler, vec2(coord) + (vec2(0.0, offset[i]) * norm)) * weight[i];
+        result += texture(textureSampler, vec2(coord) - (vec2(0.0, offset[i]) * norm)) * weight[i];
+    }
+    return result;
+}
+
+vec4 blurHorizontal(sampler2D textureSampler, vec2 coord, vec2 norm) {
+    vec4 result = vec4(0.0f);
+    for (int i = 1; i < 3; i++) {
+        result += texture(textureSampler, vec2(coord) + (vec2(offset[i], 0.0) * norm)) * weight[i];
+        result += texture(textureSampler, vec2(coord) - (vec2(offset[i], 0.0) * norm)) * weight[i];
+    }
+    return result;
+}
+
+vec4 blurDiagonal(sampler2D textureSampler, vec2 coord, vec2 norm) {
+    vec4 result = vec4(0.0f);
+    for (int i = 1; i < 3; i++) {
+        result +=
+            texture(textureSampler, vec2(coord) + (vec2(offset[i], offset[i]) * norm)) * weight[i];
+        result +=
+            texture(textureSampler, vec2(coord) - (vec2(offset[i], offset[i]) * norm)) * weight[i];
+    }
+    return result;
+}
+
+void main() {
+    vec3 base = texture(color_texture, vec2(frag_tex_coord)).rgb * weight[0];
+    vec2 tex_offset = 1.0f / textureSize(color_texture, 0);
+
+    // TODO(Blinkhawk): This code can be optimized through shader group instructions.
+    vec3 horizontal = blurHorizontal(color_texture, frag_tex_coord, tex_offset).rgb;
+    vec3 vertical = blurVertical(color_texture, frag_tex_coord, tex_offset).rgb;
+    vec3 diagonalA = blurDiagonal(color_texture, frag_tex_coord, tex_offset).rgb;
+    vec3 diagonalB = blurDiagonal(color_texture, frag_tex_coord, tex_offset * vec2(1.0, -1.0)).rgb;
+    vec3 combination = mix(mix(horizontal, vertical, 0.5f), mix(diagonalA, diagonalB, 0.5f), 0.5f);
+    color = vec4(combination + base, 1.0f);
+}