1 files changed, 40 insertions, 9 deletions

diff --git a/src/effects/shadereffectitem.cpp b/src/effects/shadereffectitem.cpp
index 8c179d8..4670a14 100644
--- a/src/effects/shadereffectitem.cpp
+++ b/src/effects/shadereffectitem.cpp
@@ -183,6 +183,7 @@ ShaderEffectSource::ShaderEffectSource(QObject *parent)
     , m_size(0, 0)
     , m_static(false)
     , m_fbo(0)
+    , m_multisampledFbo(0)
     , m_renderer(0)
     , m_refs(0)
     , m_dirtyTexture(true)
@@ -195,6 +196,7 @@ ShaderEffectSource::~ShaderEffectSource()
     if (m_refs && m_sourceItem)
         QxItemPrivate::get(m_sourceItem)->derefFromEffectItem();
     delete m_fbo;
+    delete m_multisampledFbo;
     delete m_renderer;
 }
 
@@ -402,17 +404,38 @@ void ShaderEffectSource::update()
         Q_ASSERT(m_renderer);
 
         const QGLContext *ctx = QGLContext::currentContext();
-        if (m_renderer->openGLFeatures() == 0)
+        if (m_renderer->openGLFeatures() == 0) {
             m_renderer->initializeGLFunctions(ctx);
+            QList<QByteArray> extensions = QByteArray((const char *)glGetString(GL_EXTENSIONS)).split(' ');
+            m_multisamplingSupported = extensions.contains("GL_EXT_framebuffer_multisample")
+                                    && extensions.contains("GL_EXT_framebuffer_blit");
+        }
 
         if (!m_fbo) {
-            // TODO: Implement support for multisampling.
-            QGLFramebufferObjectFormat format;
-            format.setAttachment(QGLFramebufferObject::CombinedDepthStencil);
-            format.setMipmap(m_mipmap != None);
-            m_fbo = new QGLFramebufferObject(m_size, format);
+            if (ctx->format().sampleBuffers() && m_multisamplingSupported) {
+                // If mipmapping was just enabled, m_fbo might be 0 while m_multisampledFbo != 0.
+                if (!m_multisampledFbo) {
+                    QGLFramebufferObjectFormat format;
+                    format.setAttachment(QGLFramebufferObject::CombinedDepthStencil);
+                    format.setSamples(ctx->format().samples());
+                    m_multisampledFbo = new QGLFramebufferObject(m_size, format);
+                }
+                {
+                    QGLFramebufferObjectFormat format;
+                    format.setAttachment(QGLFramebufferObject::NoAttachment);
+                    format.setMipmap(m_mipmap != None);
+                    m_fbo = new QGLFramebufferObject(m_size, format);
+                }
+            } else {
+                QGLFramebufferObjectFormat format;
+                format.setAttachment(QGLFramebufferObject::CombinedDepthStencil);
+                format.setMipmap(m_mipmap != None);
+                m_fbo = new QGLFramebufferObject(m_size, format);
+            }
         }
+
         Q_ASSERT(m_size == m_fbo->size());
+        Q_ASSERT(m_multisampledFbo == 0 || m_size == m_multisampledFbo->size());
 
         QRectF r(0, 0, m_sourceItem->width(), m_sourceItem->height());
         r.adjust(-m_margins.width(), -m_margins.height(), m_margins.width(), m_margins.height());
@@ -420,7 +443,13 @@ void ShaderEffectSource::update()
         m_renderer->setProjectMatrixToRect(r);
         m_renderer->setClearColor(Qt::transparent);
 
-        m_renderer->renderScene(BindableFbo(const_cast<QGLContext *>(QGLContext::currentContext()), m_fbo));
+        if (m_multisampledFbo) {
+            m_renderer->renderScene(BindableFbo(const_cast<QGLContext *>(QGLContext::currentContext()), m_multisampledFbo));
+            QRect r(0, 0, m_size.width(), m_size.height());
+            QGLFramebufferObject::blitFramebuffer(m_fbo, r, m_multisampledFbo, r);
+        } else {
+            m_renderer->renderScene(BindableFbo(const_cast<QGLContext *>(QGLContext::currentContext()), m_fbo));
+        }
         if (m_mipmap != None) {
             QGLFramebufferObject::bindDefault();
             glBindTexture(GL_TEXTURE_2D, m_fbo->texture());
@@ -458,7 +487,8 @@ void ShaderEffectSource::updateSizeAndTexture()
             size.setHeight(1);
         if (m_fbo && m_fbo->size() != size) {
             delete m_fbo;
-            m_fbo = 0;
+            delete m_multisampledFbo;
+            m_fbo = m_multisampledFbo = 0;
         }
         if (m_size.width() != size.width()) {
             m_size.setWidth(size.width());
@@ -472,7 +502,8 @@ void ShaderEffectSource::updateSizeAndTexture()
     } else {
         if (m_fbo) {
             delete m_fbo;
-            m_fbo = 0;
+            delete m_multisampledFbo;
+            m_fbo = m_multisampledFbo = 0;
         }
         if (!m_sourceImage.isEmpty()) {
             m_texture = QGLTexture2DPtr(new QGLTexture2D);