Fix glyph positions underflow issue

bug:16450675

Avoid using unsigned ints in math with negative numbers

Change-Id: Icdfb72451f03380dbf78b3703793869b2cd4e751

diff --git a/libs/hwui/font/Font.cpp b/libs/hwui/font/Font.cpp
index 2ea6c8c..ba878ba 100644 (file)
--- a/libs/hwui/font/Font.cpp
+++ b/libs/hwui/font/Font.cpp
@@ -140,12 +140,12 @@ void Font::invalidateTextureCache(CacheTexture* cacheTexture) {
 
 void Font::measureCachedGlyph(CachedGlyphInfo *glyph, int x, int y,
         uint8_t* bitmap, uint32_t bitmapW, uint32_t bitmapH, Rect* bounds, const float* pos) {
-    int nPenX = x + glyph->mBitmapLeft;
-    int nPenY = y + glyph->mBitmapTop;
-
     int width = (int) glyph->mBitmapWidth;
     int height = (int) glyph->mBitmapHeight;
 
+    int nPenX = x + glyph->mBitmapLeft;
+    int nPenY = y + glyph->mBitmapTop;
+
     if (bounds->bottom > nPenY) {
         bounds->bottom = nPenY;
     }
@@ -162,12 +162,12 @@ void Font::measureCachedGlyph(CachedGlyphInfo *glyph, int x, int y,
 
 void Font::drawCachedGlyph(CachedGlyphInfo* glyph, int x, int y,
         uint8_t* bitmap, uint32_t bitmapW, uint32_t bitmapH, Rect* bounds, const float* pos) {
-    float nPenX = x + glyph->mBitmapLeft;
-    float nPenY = y + glyph->mBitmapTop + glyph->mBitmapHeight;
-
     float width = (float) glyph->mBitmapWidth;
     float height = (float) glyph->mBitmapHeight;
 
+    float nPenX = x + glyph->mBitmapLeft;
+    float nPenY = y + glyph->mBitmapTop + height;
+
     float u1 = glyph->mBitmapMinU;
     float u2 = glyph->mBitmapMaxU;
     float v1 = glyph->mBitmapMinV;
@@ -181,10 +181,13 @@ void Font::drawCachedGlyph(CachedGlyphInfo* glyph, int x, int y,
 
 void Font::drawCachedGlyphTransformed(CachedGlyphInfo* glyph, int x, int y,
         uint8_t* bitmap, uint32_t bitmapW, uint32_t bitmapH, Rect* bounds, const float* pos) {
+    float width = (float) glyph->mBitmapWidth;
+    float height = (float) glyph->mBitmapHeight;
+
     SkPoint p[4];
-    p[0].iset(glyph->mBitmapLeft, glyph->mBitmapTop + glyph->mBitmapHeight);
-    p[1].iset(glyph->mBitmapLeft + glyph->mBitmapWidth, glyph->mBitmapTop + glyph->mBitmapHeight);
-    p[2].iset(glyph->mBitmapLeft + glyph->mBitmapWidth, glyph->mBitmapTop);
+    p[0].iset(glyph->mBitmapLeft, glyph->mBitmapTop + height);
+    p[1].iset(glyph->mBitmapLeft + width, glyph->mBitmapTop + height);
+    p[2].iset(glyph->mBitmapLeft + width, glyph->mBitmapTop);
     p[3].iset(glyph->mBitmapLeft, glyph->mBitmapTop);
 
     mDescription.mInverseLookupTransform.mapPoints(p, 4);