Rewrite skin rendering

Fixes rendering in Qt 6.7

Author: adazem009

src/bitmapskin.cpp

@@ -28,7 +28,7 @@ BitmapSkin::BitmapSkin(libscratchcpp::Costume *costume) :
     m_image.load(&buffer, format);
 
     // Paint the image into a texture
-    m_texture = createAndPaintTexture(m_image.width(), m_image.height(), false);
+    m_texture = createAndPaintTexture(m_image.width(), m_image.height());
     m_textureSize.setWidth(m_image.width());
     m_textureSize.setHeight(m_image.height());
 

src/skin.cpp

@@ -9,83 +9,56 @@ using namespace scratchcpprender;
 
 Skin::Skin()
 {
+    QOpenGLContext *context = QOpenGLContext::currentContext();
+    Q_ASSERT(context);
+
+    if (context) {
+        QObject::connect(context, &QOpenGLContext::aboutToBeDestroyed, &m_signalHandler, [this]() {
+            // Destroy textures
+            m_textures.clear();
+        });
+    }
 }
 
-Texture Skin::createAndPaintTexture(int width, int height, bool multisampled)
+Texture Skin::createAndPaintTexture(int width, int height)
 {
     QOpenGLContext *context = QOpenGLContext::currentContext();
 
     if (!context || !context->isValid() || (width <= 0 || height <= 0))
         return Texture();
 
-    QOpenGLFunctions glF(context);
+    QOpenGLExtraFunctions glF(context);
     glF.initializeOpenGLFunctions();
 
-    // Create offscreen surface
-    QOffscreenSurface surface;
-    surface.setFormat(context->format());
-    surface.create();
-    Q_ASSERT(surface.isValid());
-
-    // Save old surface
-    QSurface *oldSurface = context->surface();
-
-    // Make context active on the surface
-    context->makeCurrent(&surface);
-
-    const QRectF drawRect(0, 0, width, height);
-    const QSize drawRectSize = drawRect.size().toSize();
-
-    // Create multisampled FBO (if the multisampled parameter is set)
-    QOpenGLFramebufferObjectFormat format;
-    format.setAttachment(QOpenGLFramebufferObject::CombinedDepthStencil);
-
-    if (multisampled)
-        format.setSamples(16);
+    // Render to QImage
+    QImage image(width, height, QImage::Format_RGBA8888);
 
-    QOpenGLFramebufferObject fbo(drawRectSize, format);
-    fbo.bind();
+    // Clear the image to be fully transparent
+    image.fill(Qt::transparent);
 
-    // Create paint device
-    QOpenGLPaintDevice device(drawRectSize);
-    QPainter painter(&device);
-    painter.beginNativePainting();
-    painter.setRenderHint(QPainter::Antialiasing, false);
-    glF.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
-    glF.glClear(GL_COLOR_BUFFER_BIT);
-
-    // Call the skin-specific paint method
-    paint(&painter);
-
-    // Done with the painting
-    painter.endNativePainting();
+    QPainter painter(&image);
+    paint(&painter); // Custom paint function
     painter.end();
-    fbo.release();
-
-    GLuint textureHandle;
-
-    if (multisampled) {
-        // Create non-multisampled FBO (we can't take the texture from the multisampled FBO)
-        format.setSamples(0);
-
-        QOpenGLFramebufferObject targetFbo(drawRectSize, format);
-        targetFbo.bind();
-
-        // Blit the multisampled FBO to target FBO
-        QOpenGLFramebufferObject::blitFramebuffer(&targetFbo, &fbo);
-
-        // Take the texture (will call targetFbo.release())
-        textureHandle = targetFbo.takeTexture();
-    } else {
-        // Take the texture
-        textureHandle = fbo.takeTexture();
+    image.mirror();
+
+    // Premultiply alpha
+    for (int y = 0; y < image.height(); ++y) {
+        QRgb *line = reinterpret_cast<QRgb *>(image.scanLine(y));
+        for (int x = 0; x < image.width(); ++x) {
+            QColor color = QColor::fromRgba(line[x]);
+            color.setRedF(color.redF() * color.alphaF());
+            color.setGreenF(color.greenF() * color.alphaF());
+            color.setBlueF(color.blueF() * color.alphaF());
+            line[x] = color.rgba();
+        }
     }
 
-    // Restore old surface
-    context->doneCurrent();
-
-    if (oldSurface)
-        context->makeCurrent(oldSurface);
+    // Create final texture from the image
+    auto texture = std::make_shared<QOpenGLTexture>(image);
+    m_textures.push_back(texture);
+    texture->setMinificationFilter(QOpenGLTexture::LinearMipMapLinear);
+    texture->setMagnificationFilter(QOpenGLTexture::Linear);
 
-    return Texture(textureHandle, drawRectSize);
+    // Texture(texture, width, height).toImage().save("/home/adazem009/test.png");
+    return Texture(texture->textureId(), width, height);
 }

src/skin.h

@@ -22,8 +22,12 @@ class Skin
         virtual double getTextureScale(const Texture &texture) const = 0;
 
     protected:
-        Texture createAndPaintTexture(int width, int height, bool multisampled);
+        Texture createAndPaintTexture(int width, int height);
         virtual void paint(QPainter *painter) = 0;
+
+    private:
+        std::vector<std::shared_ptr<QOpenGLTexture>> m_textures;
+        QObject m_signalHandler; // for disconnecting signals after destroyed
 };
 
 } // namespace scratchcpprender

src/svgskin.cpp

@@ -9,9 +9,8 @@ using namespace scratchcpprender;
 static const int MAX_TEXTURE_DIMENSION = 2048;
 static const int INDEX_OFFSET = 8;
 
-SVGSkin::SVGSkin(libscratchcpp::Costume *costume, bool antialiasing) :
-    Skin(),
-    m_antialiasing(antialiasing)
+SVGSkin::SVGSkin(libscratchcpp::Costume *costume) :
+    Skin()
 {
     if (!costume)
         return;
@@ -86,7 +85,7 @@ Texture SVGSkin::createScaledTexture(int index)
         return Texture();
     }
 
-    const Texture texture = createAndPaintTexture(viewBox.width() * scale, viewBox.height() * scale, m_antialiasing);
+    const Texture texture = createAndPaintTexture(viewBox.width() * scale, viewBox.height() * scale);
 
     if (texture.isValid()) {
         m_textures[index] = texture.handle();

src/svgskin.h

@@ -20,7 +20,7 @@ namespace scratchcpprender
 class SVGSkin : public Skin
 {
     public:
-        SVGSkin(libscratchcpp::Costume *costume, bool antialiasing = true);
+        SVGSkin(libscratchcpp::Costume *costume);
         ~SVGSkin();
 
         Texture getTexture(double scale) const override;
@@ -37,7 +37,6 @@ class SVGSkin : public Skin
         std::unordered_map<GLuint, Texture> m_textureObjects;
         QSvgRenderer m_svgRen;
         int m_maxIndex = 0;
-        bool m_antialiasing = false;
 };
 
 } // namespace scratchcpprender

test/skins/bitmapskin_test.cpp

@@ -33,6 +33,8 @@ class BitmapSkinTest : public testing::Test
         void TearDown() override
         {
             ASSERT_EQ(m_context.surface(), &m_surface);
+            m_jpegSkin.reset();
+            m_pngSkin.reset();
             m_context.doneCurrent();
         }
 

test/skins/svgskin_test.cpp

@@ -22,12 +22,13 @@ class SVGSkinTest : public testing::Test
             Costume costume("", "", "");
             std::string costumeData = readFileStr("image.svg");
             costume.setData(costumeData.size(), costumeData.data());
-            m_skin = std::make_unique<SVGSkin>(&costume, false);
+            m_skin = std::make_unique<SVGSkin>(&costume);
         }
 
         void TearDown() override
         {
             ASSERT_EQ(m_context.surface(), &m_surface);
+            m_skin.reset();
             m_context.doneCurrent();
         }
 
@@ -59,10 +60,6 @@ TEST_F(SVGSkinTest, Textures)
             ASSERT_EQ(m_skin->getTextureScale(texture), scale);
         }
 
-        // Skip images 12, 13 and 15 because they're different on xvfb
-        if (i == 12 || i == 13 || i >= 15)
-            continue;
-
         QBuffer buffer;
         texture.toImage().save(&buffer, "png");
         QFile ref("svg_texture_results/" + QString::number(std::min(i, 15)) + ".png");