Add support for color glyphs (Emoji) on Mac OS X and iOS

A new glyph type is added to the glyph caches for ARGB bitmap glyphs,
and the raster and OpenGL paint engines have been modified to support
this glyph type for drawCachedGlyphs().

The CoreText font engine implements support for these glyphs through
the CTFontDrawGlyphs API, since CGContextShowGlyphsWithAdvances does
not handle color glyphs.

Change-Id: Idad9ce75a911cae130d65aebe59142772a16fc12
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>

1 files changed, 27 insertions, 17 deletions

diff --git a/src/gui/opengl/qopengltextureglyphcache.cpp b/src/gui/opengl/qopengltextureglyphcache.cpp
index b751629117..83f407575e 100644
--- a/src/gui/opengl/qopengltextureglyphcache.cpp
+++ b/src/gui/opengl/qopengltextureglyphcache.cpp
@@ -120,7 +120,7 @@ void QOpenGLTextureGlyphCache::createTextureData(int width, int height)
     m_textureResource->m_width = width;
     m_textureResource->m_height = height;
 
-    if (m_type == QFontEngineGlyphCache::Raster_RGBMask) {
+    if (m_type == QFontEngineGlyphCache::Raster_RGBMask || m_type == QFontEngineGlyphCache::Raster_ARGB) {
         QVarLengthArray<uchar> data(width * height * 4);
         for (int i = 0; i < data.size(); ++i)
             data[i] = 0;
@@ -314,30 +314,40 @@ void QOpenGLTextureGlyphCache::fillTexture(const Coord &c, glyph_t glyph, QFixed
             for (int x = 0; x < maskWidth; ++x)
                 src[x] = -src[x]; // convert 0 and 1 into 0 and 255
         }
-    } else if (mask.format() == QImage::Format_RGB32) {
-        // Make the alpha component equal to the average of the RGB values.
-        // This is needed when drawing sub-pixel antialiased text on translucent targets.
-        for (int y = 0; y < maskHeight; ++y) {
-            quint32 *src = (quint32 *) mask.scanLine(y);
-            for (int x = 0; x < maskWidth; ++x) {
-                uchar r = src[x] >> 16;
-                uchar g = src[x] >> 8;
-                uchar b = src[x];
-                quint32 avg = (quint32(r) + quint32(g) + quint32(b) + 1) / 3; // "+1" for rounding.
+    } else if (mask.depth() == 32) {
+        if (mask.format() == QImage::Format_RGB32
+            // We need to make the alpha component equal to the average of the RGB values.
+            // This is needed when drawing sub-pixel antialiased text on translucent targets.
+#if defined(QT_OPENGL_ES_2)
+            || !hasBGRA // We need to reverse the bytes
+#endif
+            ) {
+            for (int y = 0; y < maskHeight; ++y) {
+                quint32 *src = (quint32 *) mask.scanLine(y);
+                for (int x = 0; x < maskWidth; ++x) {
+                    uchar r = src[x] >> 16;
+                    uchar g = src[x] >> 8;
+                    uchar b = src[x];
+                    quint32 avg;
+                    if (mask.format() == QImage::Format_RGB32)
+                        avg = (quint32(r) + quint32(g) + quint32(b) + 1) / 3; // "+1" for rounding.
+                    else // Format_ARGB_Premultiplied
+                        avg = src[x] >> 24;
 
 #if defined(QT_OPENGL_ES_2)
-                if (!hasBGRA) {
-                    // Reverse bytes to match GL_RGBA
-                    src[x] = (avg << 24) | (quint32(r) << 0) | (quint32(g) << 8) | (quint32(b) << 16);
-                } else
+                    if (!hasBGRA) {
+                        // Reverse bytes to match GL_RGBA
+                        src[x] = (avg << 24) | (quint32(r) << 0) | (quint32(g) << 8) | (quint32(b) << 16);
+                    } else
 #endif
-                    src[x] = (src[x] & 0x00ffffff) | (avg << 24);
+                        src[x] = (src[x] & 0x00ffffff) | (avg << 24);
+                }
             }
         }
     }
 
     glBindTexture(GL_TEXTURE_2D, m_textureResource->m_texture);
-    if (mask.format() == QImage::Format_RGB32) {
+    if (mask.depth() == 32) {
 #if defined(QT_OPENGL_ES_2)
         glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y, maskWidth, maskHeight, hasBGRA ? GL_BGRA_EXT : GL_RGBA, GL_UNSIGNED_BYTE, mask.bits());
 #else