Remove warp texel offset, introduced drift in warp shader.

Signed-off-by: Kai Blaschke <kai.blaschke@kb-dev.net>

Author: yoyofr

src/libprojectM/MilkdropPreset/PerPixelMesh.cpp

@@ -330,7 +330,6 @@ void PerPixelMesh::WarpedBlit(const PresetState& presetState,
         perPixelMeshShader->SetUniformFloat("warpTime", warpTime);
         perPixelMeshShader->SetUniformFloat("warpScaleInverse", warpScaleInverse);
         perPixelMeshShader->SetUniformFloat4("warpFactors", warpFactors);
-        perPixelMeshShader->SetUniformFloat2("texelOffset", texelOffsets);
         perPixelMeshShader->SetUniformFloat("decay", decay);
     }
     else

src/libprojectM/MilkdropPreset/Shaders/PresetWarpVertexShaderGlsl330.vert

@@ -25,7 +25,6 @@ uniform vec4 aspect;
 uniform float warpTime;
 uniform float warpScaleInverse;
 uniform vec4 warpFactors;
-uniform vec2 texelOffset;
 uniform float decay;
 
 out vec4 frag_COLOR;
@@ -43,8 +42,8 @@ void main() {
     float v = pos.y * aspectY * 0.5 * zoom2Inverse + 0.5;
 
     // original UV coordinates
-    vec2 uv_original = vec2(pos.x * 0.5 + 0.5 + texelOffset.x,
-                            pos.y * 0.5 + 0.5 + texelOffset.y);
+    vec2 uv_original = vec2(pos.x * 0.5 + 0.5,
+                            pos.y * 0.5 + 0.5);
 
     // Stretch on X, Y
     u = (u - warp_center.x) / stretch.x + warp_center.x;
@@ -73,10 +72,6 @@ void main() {
     u = (u - 0.5) * invAspectX + 0.5;
     v = (v - 0.5) * invAspectY + 0.5;
 
-    // Final half-texel translation
-    u += texelOffset.x;
-    v += texelOffset.y;
-
     frag_COLOR = vec4(decay, decay, decay, 1.0);
     frag_TEXCOORD0.xy = vec2(u, v);
     frag_TEXCOORD0.zw = uv_original;