VideoCore: Add gaussian filtering.

src/video_core/host_shaders/CMakeLists.txt

@@ -19,6 +19,7 @@ set(SHADER_FILES
     pitch_unswizzle.comp
     present_scaleforce.frag
     present_bicubic.frag
+    present_gaussian.frag
     vulkan_blit_color_float.frag
     vulkan_blit_depth_stencil.frag
     vulkan_fidelityfx_fsr_easu.comp

src/video_core/host_shaders/present_gaussian.frag

@@ -0,0 +1,74 @@
+// Copyright 2019 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#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);
+    vec3 horizontal = blurHorizontal(color_texture, frag_tex_coord, tex_offset).rgb;
+    vec3 vertical = blurVertical(color_texture, frag_tex_coord, tex_offset).rgb;
+    vec3 diagonalA = blurVertical(color_texture, frag_tex_coord, tex_offset).rgb;
+    vec3 diagonalB = blurVertical(color_texture, frag_tex_coord, -tex_offset).rgb;
+    vec3 combination = mix(mix(horizontal, vertical, 0.5f), mix(diagonalA, diagonalB, 0.5f), 0.5f);
+    color = vec4(combination + base, 1.0f);
+}