From 622114dfb539862e5fde11d5818a41399063ed67 Mon Sep 17 00:00:00 2001
From: Arjen Hiemstra <ahiemstra@heimr.nl>
Date: Thu, 12 Jan 2023 14:06:52 +0100
Subject: [PATCH] Move texture coordinate post processing into a method of
 RenderGeometry

This allows us to reuse the code in other places.
---
 src/libkwineffects/kwineffects.cpp | 12 ++++++++++++
 src/libkwineffects/kwineffects.h   | 11 +++++++++++
 src/scene/itemrenderer_opengl.cpp  | 11 +----------
 3 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/src/libkwineffects/kwineffects.cpp b/src/libkwineffects/kwineffects.cpp
index d7cad1dae6..d8711b45ef 100644
--- a/src/libkwineffects/kwineffects.cpp
+++ b/src/libkwineffects/kwineffects.cpp
@@ -1182,6 +1182,18 @@ void RenderGeometry::appendSubQuad(const WindowQuad &quad, const QRectF &subquad
     append(vertices[2]);
 }
 
+void RenderGeometry::postProcessTextureCoordinates(const QMatrix4x4 &textureMatrix)
+{
+    if (!textureMatrix.isIdentity()) {
+        const QVector2D coeff(textureMatrix(0, 0), textureMatrix(1, 1));
+        const QVector2D offset(textureMatrix(0, 3), textureMatrix(1, 3));
+
+        for (auto &vertex : (*this)) {
+            vertex.texcoord = vertex.texcoord * coeff + offset;
+        }
+    }
+}
+
 /***************************************************************
  Motion1D
 ***************************************************************/
diff --git a/src/libkwineffects/kwineffects.h b/src/libkwineffects/kwineffects.h
index d7bc2a3557..7591d1ef4d 100644
--- a/src/libkwineffects/kwineffects.h
+++ b/src/libkwineffects/kwineffects.h
@@ -3051,6 +3051,17 @@ public:
      *                    device coordinates.
      */
     void appendSubQuad(const WindowQuad &quad, const QRectF &subquad, qreal deviceScale);
+    /**
+     * Modify this geometry's texture coordinates based on a matrix.
+     *
+     * This is primarily intended to convert from non-normalised to normalised
+     * texture coordinates.
+     *
+     * @param textureMatrix The texture matrix to use for modifying the
+     *                      texture coordinates. Note that only the 2D scale and
+     *                      translation are used.
+     */
+    void postProcessTextureCoordinates(const QMatrix4x4 &textureMatrix);
 
 private:
     VertexSnappingMode m_vertexSnappingMode = VertexSnappingMode::Round;
diff --git a/src/scene/itemrenderer_opengl.cpp b/src/scene/itemrenderer_opengl.cpp
index 1cbee36816..3f8463efa1 100644
--- a/src/scene/itemrenderer_opengl.cpp
+++ b/src/scene/itemrenderer_opengl.cpp
@@ -304,16 +304,7 @@ void ItemRendererOpenGL::renderItem(Item *item, int mask, const QRegion &region,
         renderNode.firstVertex = v;
         renderNode.vertexCount = renderNode.geometry.count();
 
-        const QMatrix4x4 textureMatrix = renderNode.texture->matrix(renderNode.coordinateType);
-        if (!textureMatrix.isIdentity()) {
-            // Adjust the vertex' texture coordinates with the specified matrix.
-            const QVector2D coeff(textureMatrix(0, 0), textureMatrix(1, 1));
-            const QVector2D offset(textureMatrix(0, 3), textureMatrix(1, 3));
-
-            for (auto &vertex : renderNode.geometry) {
-                vertex.texcoord = vertex.texcoord * coeff + offset;
-            }
-        }
+        renderNode.geometry.postProcessTextureCoordinates(renderNode.texture->matrix(renderNode.coordinateType));
 
         renderNode.geometry.copy(std::span(&map[v], renderNode.geometry.count()));
         v += renderNode.geometry.count();