Fix textdrawing under GL on N900.

The driver in the N900 doesn't support glCopyTexSubImage
or glReadPixels for FBO's that have a GL_ALPHA or POT
color attachment. The ifdef'ed code in resize() was
a previous attempt to make this work which didn't.

We could have changed the texture to be GL_RGBA and changed
the texture size to be NPOT, but that would have wasted
precious GPU memory and would have been slower, so we
waste a bit of system memory instead, by having a QImage
copy along with the texture.

Reviewed-by: Eskil
Reviewed-by: Trond

1 files changed, 3 insertions, 2 deletions

diff --git a/src/opengl/gl2paintengineex/qtextureglyphcache_gl_p.h b/src/opengl/gl2paintengineex/qtextureglyphcache_gl_p.h
index 75c2bb1..efb7435 100644
--- a/src/opengl/gl2paintengineex/qtextureglyphcache_gl_p.h
+++ b/src/opengl/gl2paintengineex/qtextureglyphcache_gl_p.h
@@ -62,7 +62,7 @@ QT_BEGIN_NAMESPACE
 
 class QGL2PaintEngineExPrivate;
 
-class Q_OPENGL_EXPORT QGLTextureGlyphCache : public QObject, public QTextureGlyphCache
+class Q_OPENGL_EXPORT QGLTextureGlyphCache : public QObject, public QImageTextureGlyphCache
 {
     Q_OBJECT
 public:
@@ -72,7 +72,6 @@ public:
     virtual void createTextureData(int width, int height);
     virtual void resizeTextureData(int width, int height);
     virtual void fillTexture(const Coord &c, glyph_t glyph);
-    virtual int glyphMargin() const;
     virtual int glyphPadding() const;
 
     inline GLuint texture() const { return m_texture; }
@@ -116,6 +115,8 @@ private:
     int m_height;
 
     QGLShaderProgram *m_program;
+
+    bool m_broken_fbo_readback;
 };
 
 QT_END_NAMESPACE