remove GetGammaFlag from SkFontHost

prep for retooling of gamma support



git-svn-id: http://skia.googlecode.com/svn/trunk@2730 2bbb7eff-a529-9590-31e7-b0007b416f81

2 files changed, 38 insertions, 35 deletions

diff --git a/src/core/SkPaint.cpp b/src/core/SkPaint.cpp
index 06201d3694..e89e281406 100644
--- a/src/core/SkPaint.cpp
+++ b/src/core/SkPaint.cpp
@@ -1266,6 +1266,43 @@ static SkPaint::Hinting computeHinting(const SkPaint& paint) {
     return h;
 }
 
+// return true if the paint is just a single color (i.e. not a shader). If its
+// a shader, then we can't compute a const luminance for it :(
+static bool justAColor(const SkPaint& paint, SkColor* color) {
+    if (paint.getShader()) {
+        return false;
+    }
+    SkColor c = paint.getColor();
+    if (paint.getColorFilter()) {
+        c = paint.getColorFilter()->filterColor(c);
+    }
+    if (color) {
+        *color = c;
+    }
+    return true;
+}
+
+// returns 0..kLuminance_Max
+static unsigned computeGammaFlag(const SkPaint& paint) {
+    SkColor c;
+    if (justAColor(paint, &c)) {
+        int r = SkColorGetR(c);
+        int g = SkColorGetG(c);
+        int b = SkColorGetB(c);
+        // compute luminance to 11 bits (0..0x3F)
+        int luminance = r * 2 + g * 5 + b >> 3;
+
+        if (luminance <= 0x40) {
+            return SkScalerContext::kGammaForBlack_Flag;
+        }
+        if (luminance >= 0xA0) {
+            return SkScalerContext::kGammaForWhite_Flag;
+        }
+    }
+    // if we're not a single color, return the middle of the luminance range
+    return 0;
+}
+
 // Beyond this size, LCD doesn't appreciably improve quality, but it always
 // cost more RAM and draws slower, so we set a cap.
 #ifndef SK_MAX_SIZE_FOR_LCDTEXT
@@ -1317,7 +1354,7 @@ void SkScalerContext::MakeRec(const SkPaint& paint,
     SkPaint::Style  style = paint.getStyle();
     SkScalar        strokeWidth = paint.getStrokeWidth();
 
-    unsigned flags = SkFontHost::ComputeGammaFlag(paint);
+    unsigned flags = computeGammaFlag(paint);
 
     if (paint.isFakeBoldText()) {
 #ifdef SK_USE_FREETYPE_EMBOLDEN
diff --git a/src/core/SkScalerContext.cpp b/src/core/SkScalerContext.cpp
index 27481f8a1f..8727bb7a17 100644
--- a/src/core/SkScalerContext.cpp
+++ b/src/core/SkScalerContext.cpp
@@ -21,9 +21,6 @@
 
 #define ComputeBWRowBytes(width)        (((unsigned)(width) + 7) >> 3)
 
-static const uint8_t* gBlackGammaTable;
-static const uint8_t* gWhiteGammaTable;
-
 void SkGlyph::toMask(SkMask* mask) const {
     SkASSERT(mask);
 
@@ -77,15 +74,6 @@ static SkFlattenable* load_flattenable(const SkDescriptor* desc, uint32_t tag) {
 SkScalerContext::SkScalerContext(const SkDescriptor* desc)
     : fPathEffect(NULL), fMaskFilter(NULL)
 {
-    static bool gHaveGammaTables;
-    if (!gHaveGammaTables) {
-        const uint8_t* tables[2];
-        SkFontHost::GetGammaTables(tables);
-        gBlackGammaTable = tables[0];
-        gWhiteGammaTable = tables[1];
-        gHaveGammaTables = true;
-    }
-
     fBaseGlyphCount = 0;
     fNextContext = NULL;
 
@@ -563,28 +551,6 @@ void SkScalerContext::getImage(const SkGlyph& origGlyph) {
             SkMask::FreeImage(dstM.fImage);
         }
     }
-
-    // check to see if we should filter the alpha channel
-
-    if (NULL == fMaskFilter &&
-        fRec.fMaskFormat != SkMask::kBW_Format &&
-        fRec.fMaskFormat != SkMask::kLCD16_Format &&
-        fRec.fMaskFormat != SkMask::kLCD32_Format &&
-        (fRec.fFlags & (kGammaForBlack_Flag | kGammaForWhite_Flag)) != 0)
-    {
-        const uint8_t* table = (fRec.fFlags & kGammaForBlack_Flag) ? gBlackGammaTable : gWhiteGammaTable;
-        if (NULL != table) {
-            uint8_t* dst = (uint8_t*)origGlyph.fImage;
-            unsigned rowBytes = origGlyph.rowBytes();
-
-            for (int y = origGlyph.fHeight - 1; y >= 0; --y) {
-                for (int x = origGlyph.fWidth - 1; x >= 0; --x) {
-                    dst[x] = table[dst[x]];
-                }
-                dst += rowBytes;
-            }
-        }
-    }
 }
 
 void SkScalerContext::getPath(const SkGlyph& glyph, SkPath* path) {