Fixes: Use the blit/multisample FBO API in the framebuffer object example.

RevBy:    Trond

2 files changed, 26 insertions, 5 deletions

diff --git a/examples/opengl/framebufferobject/glwidget.cpp b/examples/opengl/framebufferobject/glwidget.cpp
index d3591d6..3cb3929 100644
--- a/examples/opengl/framebufferobject/glwidget.cpp
+++ b/examples/opengl/framebufferobject/glwidget.cpp
@@ -53,7 +53,18 @@ GLWidget::GLWidget(QWidget *parent)
 {
     setWindowTitle(tr("OpenGL framebuffer objects"));
     makeCurrent();
-    fbo = new QGLFramebufferObject(1024, 1024);
+
+    if (QGLFramebufferObject::hasOpenGLFramebufferBlit()) {
+        QGLFramebufferObjectFormat format;
+        format.setSamples(4);
+
+        render_fbo = new QGLFramebufferObject(512, 512, format);
+        texture_fbo = new QGLFramebufferObject(512, 512);
+    } else {
+        render_fbo = new QGLFramebufferObject(1024, 1024);
+        texture_fbo = render_fbo;
+    }
+
     rot_x = rot_y = rot_z = 0.0f;
     scale = 0.1f;
     anim = new QTimeLine(750, this);
@@ -113,7 +124,9 @@ GLWidget::~GLWidget()
 {
     delete[] wave;
     glDeleteLists(tile_list, 1);
-    delete fbo;
+    delete texture_fbo;
+    if (render_fbo != texture_fbo)
+        delete render_fbo;
 }
 
 void GLWidget::paintEvent(QPaintEvent *)
@@ -129,10 +142,16 @@ void GLWidget::draw()
     saveGLState();
 
     // render the 'bubbles.svg' file into our framebuffer object
-    QPainter fbo_painter(fbo);
+    QPainter fbo_painter(render_fbo);
     svg_renderer->render(&fbo_painter);
     fbo_painter.end();
 
+    if (render_fbo != texture_fbo) {
+        QRect rect(0, 0, render_fbo->width(), render_fbo->height());
+        QGLFramebufferObject::blitFramebuffer(texture_fbo, rect,
+                                              render_fbo, rect);
+    }
+
     // draw into the GL widget
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
     glMatrixMode(GL_PROJECTION);
@@ -145,8 +164,9 @@ void GLWidget::draw()
     glEnable(GL_BLEND);
     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 
-    glBindTexture(GL_TEXTURE_2D, fbo->texture());
+    glBindTexture(GL_TEXTURE_2D, texture_fbo->texture());
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
     glEnable(GL_TEXTURE_2D);
     glEnable(GL_MULTISAMPLE);
     glEnable(GL_CULL_FACE);
diff --git a/examples/opengl/framebufferobject/glwidget.h b/examples/opengl/framebufferobject/glwidget.h
index b64cfa8..d97ef78 100644
--- a/examples/opengl/framebufferobject/glwidget.h
+++ b/examples/opengl/framebufferobject/glwidget.h
@@ -77,6 +77,7 @@ private:
     QImage logo;
     QTimeLine *anim;
     QSvgRenderer *svg_renderer;
-    QGLFramebufferObject *fbo;
+    QGLFramebufferObject *render_fbo;
+    QGLFramebufferObject *texture_fbo;
 };