Fix text disappearing on GL when RGB-path is taken (no transformation)

When there is no transformation on a glyph in the GL texture glyph
cache, it will take the RGB code path to support subpixel antialiasing.
In this code path we would ask glTextImage2D() to convert from a
GL_ALPHA buffer to an internal format of GL_RGBA. This is not supported
on OpenGL ES 2, and would cause missing text for some drivers.

The change also fixes a typo in an #ifdef.

Task-number: QTBUG-15789
Reviewed-by: Kim

1 files changed, 11 insertions, 8 deletions

diff --git a/src/opengl/gl2paintengineex/qtextureglyphcache_gl.cpp b/src/opengl/gl2paintengineex/qtextureglyphcache_gl.cpp
index 705ad09..66445cd 100644
--- a/src/opengl/gl2paintengineex/qtextureglyphcache_gl.cpp
+++ b/src/opengl/gl2paintengineex/qtextureglyphcache_gl.cpp
@@ -128,14 +128,17 @@ void QGLTextureGlyphCache::createTextureData(int width, int height)
     m_width = width;
     m_height = height;
 
-    QVarLengthArray<uchar> data(width * height);
-    for (int i = 0; i < data.size(); ++i)
-        data[i] = 0;
-
-    if (m_type == QFontEngineGlyphCache::Raster_RGBMask)
-        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_ALPHA, GL_UNSIGNED_BYTE, &data[0]);
-    else
+    if (m_type == QFontEngineGlyphCache::Raster_RGBMask) {
+        QVarLengthArray<uchar> data(width * height * 4);
+        for (int i = 0; i < data.size(); ++i)
+            data[i] = 0;
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, &data[0]);
+    } else {
+        QVarLengthArray<uchar> data(width * height);
+        for (int i = 0; i < data.size(); ++i)
+            data[i] = 0;
         glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, width, height, 0, GL_ALPHA, GL_UNSIGNED_BYTE, &data[0]);
+    }
 
     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
@@ -287,7 +290,7 @@ void QGLTextureGlyphCache::fillTexture(const Coord &c, glyph_t glyph)
     if (mask.format() == QImage::Format_RGB32) {
         glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y, maskWidth, maskHeight, GL_BGRA, GL_UNSIGNED_BYTE, mask.bits());
     } else {
-#ifdef QT_OPENGL_ES2
+#ifdef QT_OPENGL_ES_2
         glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y, maskWidth, maskHeight, GL_ALPHA, GL_UNSIGNED_BYTE, mask.bits());
 #else
         // glTexSubImage2D() might cause some garbage to appear in the texture if the mask width is