[client] egl: rework post process filters and add AMD FXR

client/renderers/EGL/shader/ffx_fsr1_easu.frag

@@ -0,0 +1,48 @@
+#version 300 es
+precision mediump float;
+
+#include "compat.h"
+
+in  vec2  iFragCoord;
+out vec4  fragColor;
+
+uniform sampler2D iChannel0;
+uniform uvec2     uInRes[8];
+uniform uvec2     uOutRes;
+
+#define A_GPU  1
+#define A_GLSL 1
+#define A_FULL 1
+
+#include "ffx_a.h"
+
+#define FSR_EASU_F 1
+#define FSR_RCAS_F 1
+
+AF4 FsrEasuRF(AF2 p){return AF4(textureGather(iChannel0, p, 0));}
+AF4 FsrEasuGF(AF2 p){return AF4(textureGather(iChannel0, p, 1));}
+AF4 FsrEasuBF(AF2 p){return AF4(textureGather(iChannel0, p, 2));}
+
+#include "ffx_fsr1.h"
+
+void main()
+{
+  AU4 con0, con1, con2, con3;
+  vec2 inRes  = vec2(uInRes[0]);
+  vec2 outRes = vec2(uOutRes);
+
+  FsrEasuCon(
+    con0,
+    con1,
+    con2,
+    con3,
+    inRes.x , inRes.y,
+    inRes.x , inRes.y,
+    outRes.x, outRes.y
+  );
+
+  vec3 color;
+  uvec2 point = uvec2(iFragCoord * outRes);
+  FsrEasuF(color, point, con0, con1, con2, con3);
+  fragColor = vec4(color.xyz, 1);
+}