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LNXSDK/leenkx/Shaders/fsr1_easu_pass/fsr1_easu_pass.frag.glsl
2026-02-24 11:44:01 -08:00

158 lines
4.6 KiB
GLSL

#version 450
// AMD FidelityFX Super Resolution 1.0.2 - EASU (Edge Adaptive Spatial Upsampling)
#include "compiled.inc"
uniform sampler2D tex;
uniform vec2 screenSize;
in vec2 texCoord;
out vec4 fragColor;
// Helper functions from AMD ffx_a.h
float APrxLoRcpF1(float a) {
return uintBitsToFloat(uint(0x7ef07ebb) - floatBitsToUint(a));
}
float AMax3F1(float x, float y, float z) {
return max(x, max(y, z));
}
float AMin3F1(float x, float y, float z) {
return min(x, min(y, z));
}
// Attempt to use textureGather for efficiency when available
#if __VERSION__ >= 400
void FsrEasuTap(
inout vec3 aC,
inout float aW,
vec2 off,
vec2 dir,
vec2 len,
float lob,
float clp,
vec3 c
) {
vec2 v = off * dir;
float d2 = v.x + v.y;
d2 = clamp(d2 * APrxLoRcpF1(max(abs(v.x), abs(v.y))), 0.0, 1.0);
d2 = d2 * d2;
d2 = d2 * len.x + len.y;
float wB = 2.0 / 5.0 * d2 - 1.0;
float wA = lob * d2 - 1.0;
wB *= wB;
wA *= wA;
float w = 25.0 / 16.0 * wA * wB;
w = min(w, clp);
w = max(w, 0.0);
aC += c * w;
aW += w;
}
vec3 FsrEasuF(vec2 ip) {
vec2 inputSize = textureSize(tex, 0);
vec2 inputRcp = 1.0 / inputSize;
// Position in input pixels
vec2 pp = ip * inputSize - 0.5;
vec2 fp = floor(pp);
pp -= fp;
// 12-tap kernel
// b c
// e f g h
// i j k l
// n o
ivec2 sp = ivec2(fp);
vec3 b = texelFetch(tex, sp + ivec2(0, -1), 0).rgb;
vec3 c = texelFetch(tex, sp + ivec2(1, -1), 0).rgb;
vec3 e = texelFetch(tex, sp + ivec2(-1, 0), 0).rgb;
vec3 f = texelFetch(tex, sp + ivec2(0, 0), 0).rgb;
vec3 g = texelFetch(tex, sp + ivec2(1, 0), 0).rgb;
vec3 h = texelFetch(tex, sp + ivec2(2, 0), 0).rgb;
vec3 i = texelFetch(tex, sp + ivec2(-1, 1), 0).rgb;
vec3 j = texelFetch(tex, sp + ivec2(0, 1), 0).rgb;
vec3 k = texelFetch(tex, sp + ivec2(1, 1), 0).rgb;
vec3 l = texelFetch(tex, sp + ivec2(2, 1), 0).rgb;
vec3 n = texelFetch(tex, sp + ivec2(0, 2), 0).rgb;
vec3 o = texelFetch(tex, sp + ivec2(1, 2), 0).rgb;
// Luma for edge detection (using green channel approximation)
float bL = b.g + 0.5 * (b.r + b.b);
float cL = c.g + 0.5 * (c.r + c.b);
float eL = e.g + 0.5 * (e.r + e.b);
float fL = f.g + 0.5 * (f.r + f.b);
float gL = g.g + 0.5 * (g.r + g.b);
float hL = h.g + 0.5 * (h.r + h.b);
float iL = i.g + 0.5 * (i.r + i.b);
float jL = j.g + 0.5 * (j.r + j.b);
float kL = k.g + 0.5 * (k.r + k.b);
float lL = l.g + 0.5 * (l.r + l.b);
float nL = n.g + 0.5 * (n.r + n.b);
float oL = o.g + 0.5 * (o.r + o.b);
// Gradient detection
float dirX = (cL - bL) + (gL - fL) + (kL - jL) + (oL - nL);
float dirY = (eL - iL) + (fL - jL) + (gL - kL) + (hL - lL);
// Normalize direction
float dirR = APrxLoRcpF1(max(abs(dirX), abs(dirY)));
dirX *= dirR;
dirY *= dirR;
// Calculate stretch based on edge direction
float len = length(vec2(dirX, dirY));
len = len * 0.5;
len *= len;
float stretch = (dirX * dirX + dirY * dirY) * APrxLoRcpF1(max(abs(dirX), abs(dirY)));
vec2 len2 = vec2(1.0 + (stretch - 1.0) * len, 1.0 - 0.5 * len);
float lob = 0.5 + (0.25 - 0.04 - 0.5) * len;
float clp = APrxLoRcpF1(lob);
// Accumulate samples
vec3 aC = vec3(0.0);
float aW = 0.0;
vec2 dir = vec2(dirX, dirY);
FsrEasuTap(aC, aW, vec2(0.0, -1.0) - pp, dir, len2, lob, clp, b);
FsrEasuTap(aC, aW, vec2(1.0, -1.0) - pp, dir, len2, lob, clp, c);
FsrEasuTap(aC, aW, vec2(-1.0, 0.0) - pp, dir, len2, lob, clp, e);
FsrEasuTap(aC, aW, vec2(0.0, 0.0) - pp, dir, len2, lob, clp, f);
FsrEasuTap(aC, aW, vec2(1.0, 0.0) - pp, dir, len2, lob, clp, g);
FsrEasuTap(aC, aW, vec2(2.0, 0.0) - pp, dir, len2, lob, clp, h);
FsrEasuTap(aC, aW, vec2(-1.0, 1.0) - pp, dir, len2, lob, clp, i);
FsrEasuTap(aC, aW, vec2(0.0, 1.0) - pp, dir, len2, lob, clp, j);
FsrEasuTap(aC, aW, vec2(1.0, 1.0) - pp, dir, len2, lob, clp, k);
FsrEasuTap(aC, aW, vec2(2.0, 1.0) - pp, dir, len2, lob, clp, l);
FsrEasuTap(aC, aW, vec2(0.0, 2.0) - pp, dir, len2, lob, clp, n);
FsrEasuTap(aC, aW, vec2(1.0, 2.0) - pp, dir, len2, lob, clp, o);
// Normalize
vec3 pix = aC / aW;
// Clamp to neighborhood min/max to prevent ringing
vec3 mn = min(min(min(f, g), j), k);
vec3 mx = max(max(max(f, g), j), k);
pix = clamp(pix, mn, mx);
return pix;
}
#else
// Fallback for older GLSL - simple bilinear
vec3 FsrEasuF(vec2 ip) {
return texture(tex, ip).rgb;
}
#endif
void main() {
vec3 col = FsrEasuF(texCoord);
fragColor = vec4(col, 1.0);
}