// Copyright 2019 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#version 460 core
layout (location = 0) in vec2 frag_tex_coord;
layout (location = 0) out vec4 color;
layout (binding = 1) uniform sampler2D color_texture;
vec4 cubic(float v) {
vec4 n = vec4(1.0, 2.0, 3.0, 4.0) - v;
vec4 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) * (1.0 / 6.0);
}
vec4 textureBicubic( sampler2D textureSampler, vec2 texCoords ) {
vec2 texSize = textureSize(textureSampler, 0);
vec2 invTexSize = 1.0 / texSize;
texCoords = texCoords * texSize - 0.5;
vec2 fxy = fract(texCoords);
texCoords -= fxy;
vec4 xcubic = cubic(fxy.x);
vec4 ycubic = cubic(fxy.y);
vec4 c = texCoords.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 *= invTexSize.xxyy;
vec4 sample0 = texture(textureSampler, offset.xz);
vec4 sample1 = texture(textureSampler, offset.yz);
vec4 sample2 = texture(textureSampler, offset.xw);
vec4 sample3 = texture(textureSampler, offset.yw);
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);
}
void main() {
color = vec4(textureBicubic(color_texture, frag_tex_coord).rgb, 1.0f);
}