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

@@ -307,10 +307,6 @@ void PerPixelMesh::WarpedBlit(const PresetState& presetState,
         11.49f + 4.0f * cosf(warpTime * 0.933f + 5),
     };
 
-    // Texel alignment
-    glm::vec2 const texelOffsets{presetState.renderContext.texelOffsetX / static_cast<float>(presetState.renderContext.viewportSizeX),
-                                 presetState.renderContext.texelOffsetY / static_cast<float>(presetState.renderContext.viewportSizeY)};
-
     // Decay
     float decay = std::min(static_cast<float>(*perFrameContext.decay), 1.0f);
 
@@ -319,19 +315,17 @@ void PerPixelMesh::WarpedBlit(const PresetState& presetState,
 
     if (!m_warpShader)
     {
-        auto perPixelMeshShader = GetDefaultWarpShader(presetState);
-        perPixelMeshShader->Bind();
-        perPixelMeshShader->SetUniformMat4x4("vertex_transformation", PresetState::orthogonalProjection);
-        perPixelMeshShader->SetUniformInt("texture_sampler", 0);
-        perPixelMeshShader->SetUniformFloat4("aspect", {presetState.renderContext.aspectX,
-                                                        presetState.renderContext.aspectY,
-                                                        presetState.renderContext.invAspectX,
-                                                        presetState.renderContext.invAspectY});
-        perPixelMeshShader->SetUniformFloat("warpTime", warpTime);
-        perPixelMeshShader->SetUniformFloat("warpScaleInverse", warpScaleInverse);
-        perPixelMeshShader->SetUniformFloat4("warpFactors", warpFactors);
-        perPixelMeshShader->SetUniformFloat2("texelOffset", texelOffsets);
-        perPixelMeshShader->SetUniformFloat("decay", decay);
+        m_perPixelMeshShader.Bind();
+        m_perPixelMeshShader.SetUniformMat4x4("vertex_transformation", PresetState::orthogonalProjection);
+        m_perPixelMeshShader.SetUniformInt("texture_sampler", 0);
+        m_perPixelMeshShader.SetUniformFloat4("aspect", {presetState.renderContext.aspectX,
+                                                         presetState.renderContext.aspectY,
+                                                         presetState.renderContext.invAspectX,
+                                                         presetState.renderContext.invAspectY});
+        m_perPixelMeshShader.SetUniformFloat("warpTime", warpTime);
+        m_perPixelMeshShader.SetUniformFloat("warpScaleInverse", warpScaleInverse);
+        m_perPixelMeshShader.SetUniformFloat4("warpFactors", warpFactors);
+        m_perPixelMeshShader.SetUniformFloat("decay", decay);
     }
     else
     {
@@ -344,7 +338,6 @@ void PerPixelMesh::WarpedBlit(const PresetState& presetState,
         shader.SetUniformFloat("warpTime", warpTime);
         shader.SetUniformFloat("warpScaleInverse", warpScaleInverse);
         shader.SetUniformFloat4("warpFactors", warpFactors);
-        shader.SetUniformFloat2("texelOffset", texelOffsets);
         shader.SetUniformFloat("decay", decay);
     }
 

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;