diff options
Diffstat (limited to 'src/video_core/host_shaders/present_scaleforce.frag')
-rw-r--r-- | src/video_core/host_shaders/present_scaleforce.frag | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/src/video_core/host_shaders/present_scaleforce.frag b/src/video_core/host_shaders/present_scaleforce.frag new file mode 100644 index 000000000..1829a9be8 --- /dev/null +++ b/src/video_core/host_shaders/present_scaleforce.frag @@ -0,0 +1,145 @@ +// MIT License +// +// Copyright (c) 2020 BreadFish64 +// +// Permission is hereby granted, free of charge, to any person obtaining a copy +// of this software and associated documentation files (the "Software"), to deal +// in the Software without restriction, including without limitation the rights +// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +// copies of the Software, and to permit persons to whom the Software is +// furnished to do so, subject to the following conditions: +// +// The above copyright notice and this permission notice shall be included in all +// copies or substantial portions of the Software. +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +// SOFTWARE. + +// Adapted from https://github.com/BreadFish64/ScaleFish/tree/master/scaleforce + +#version 460 + +#ifdef VULKAN + +#define BINDING_COLOR_TEXTURE 1 + +#else // ^^^ Vulkan ^^^ // vvv OpenGL vvv + +#define BINDING_COLOR_TEXTURE 0 + +#endif + +layout (location = 0) in vec2 tex_coord; + +layout (location = 0) out vec4 frag_color; + +layout (binding = BINDING_COLOR_TEXTURE) uniform sampler2D input_texture; + +vec2 tex_size; +vec2 inv_tex_size; + +vec4 cubic(float v) { + vec3 n = vec3(1.0, 2.0, 3.0) - v; + vec3 s = n * n * n; + float x = s.x; + float y = s.y - 4.0 * s.x; + float z = s.z - 4.0 * s.y + 6.0 * s.x; + float w = 6.0 - x - y - z; + return vec4(x, y, z, w) / 6.0; +} + +// Bicubic interpolation +vec4 textureBicubic(vec2 tex_coords) { + tex_coords = tex_coords * tex_size - 0.5; + + vec2 fxy = modf(tex_coords, tex_coords); + + vec4 xcubic = cubic(fxy.x); + vec4 ycubic = cubic(fxy.y); + + vec4 c = tex_coords.xxyy + vec2(-0.5, +1.5).xyxy; + + vec4 s = vec4(xcubic.xz + xcubic.yw, ycubic.xz + ycubic.yw); + vec4 offset = c + vec4(xcubic.yw, ycubic.yw) / s; + + offset *= inv_tex_size.xxyy; + + vec4 sample0 = textureLod(input_texture, offset.xz, 0.0); + vec4 sample1 = textureLod(input_texture, offset.yz, 0.0); + vec4 sample2 = textureLod(input_texture, offset.xw, 0.0); + vec4 sample3 = textureLod(input_texture, offset.yw, 0.0); + + float sx = s.x / (s.x + s.y); + float sy = s.z / (s.z + s.w); + + return mix(mix(sample3, sample2, sx), mix(sample1, sample0, sx), sy); +} + +mat4x3 center_matrix; +vec4 center_alpha; + +// Finds the distance between four colors and cc in YCbCr space +vec4 ColorDist(vec4 A, vec4 B, vec4 C, vec4 D) { + // https://en.wikipedia.org/wiki/YCbCr#ITU-R_BT.2020_conversion + const vec3 K = vec3(0.2627, 0.6780, 0.0593); + const float LUMINANCE_WEIGHT = .6; + const mat3 YCBCR_MATRIX = + mat3(K * LUMINANCE_WEIGHT, -.5 * K.r / (1.0 - K.b), -.5 * K.g / (1.0 - K.b), .5, .5, + -.5 * K.g / (1.0 - K.r), -.5 * K.b / (1.0 - K.r)); + + mat4x3 colors = mat4x3(A.rgb, B.rgb, C.rgb, D.rgb) - center_matrix; + mat4x3 YCbCr = YCBCR_MATRIX * colors; + vec4 color_dist = vec3(1.0) * YCbCr; + color_dist *= color_dist; + vec4 alpha = vec4(A.a, B.a, C.a, D.a); + + return sqrt((color_dist + abs(center_alpha - alpha)) * alpha * center_alpha); +} + +void main() { + vec4 bl = textureLodOffset(input_texture, tex_coord, 0.0, ivec2(-1, -1)); + vec4 bc = textureLodOffset(input_texture, tex_coord, 0.0, ivec2(0, -1)); + vec4 br = textureLodOffset(input_texture, tex_coord, 0.0, ivec2(1, -1)); + vec4 cl = textureLodOffset(input_texture, tex_coord, 0.0, ivec2(-1, 0)); + vec4 cc = textureLod(input_texture, tex_coord, 0.0); + vec4 cr = textureLodOffset(input_texture, tex_coord, 0.0, ivec2(1, 0)); + vec4 tl = textureLodOffset(input_texture, tex_coord, 0.0, ivec2(-1, 1)); + vec4 tc = textureLodOffset(input_texture, tex_coord, 0.0, ivec2(0, 1)); + vec4 tr = textureLodOffset(input_texture, tex_coord, 0.0, ivec2(1, 1)); + + + tex_size = vec2(textureSize(input_texture, 0)); + inv_tex_size = 1.0 / tex_size; + center_matrix = mat4x3(cc.rgb, cc.rgb, cc.rgb, cc.rgb); + center_alpha = cc.aaaa; + + vec4 offset_tl = ColorDist(tl, tc, tr, cr); + vec4 offset_br = ColorDist(br, bc, bl, cl); + + // Calculate how different cc is from the texels around it + float total_dist = dot(offset_tl + offset_br, vec4(1.0)); + + // Add together all the distances with direction taken into account + vec4 tmp = offset_tl - offset_br; + vec2 total_offset = tmp.wy + tmp.zz + vec2(-tmp.x, tmp.x); + + if (total_dist == 0.0) { + // Doing bicubic filtering just past the edges where the offset is 0 causes black floaters + // and it doesn't really matter which filter is used when the colors aren't changing. + frag_color = vec4(cc.rgb, 1.0f); + } else { + // When the image has thin points, they tend to split apart. + // This is because the texels all around are different + // and total_offset reaches into clear areas. + // This works pretty well to keep the offset in bounds for these cases. + float clamp_val = length(total_offset) / total_dist; + vec2 final_offset = clamp(total_offset, -clamp_val, clamp_val) * inv_tex_size; + + frag_color = vec4(textureBicubic(tex_coord - final_offset).rgb, 1.0f); + } +} |