Support for non-DOM canvases/contexts (backed by bitaps).

runtime/embedders/openglui/common/canvas_state.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "embedders/openglui/common/canvas_state.h"
 
 #include <ctype.h>
 #include <string.h>
 
 #include "embedders/openglui/common/support.h"
@@ skipping 122 matching lines @@
   return baseline;
 }
 
 const char* CanvasState::setTextDirection(const char* direction) {
     // TODO(gram): Add support for this if Skia does.
   return direction;
 }
 
 void CanvasState::setGlobalCompositeOperation(const char* op) {
   SkXfermode::Mode mode;
-  if (strcmp(op, "source-atop") == 0) {
-    mode = SkXfermode::kSrcATop_Mode;
-  } else if (strcmp(op, "source-in") == 0) {
-    mode = SkXfermode::kSrcIn_Mode;
-  } else if (strcmp(op, "source-out") == 0) {
-    mode = SkXfermode::kSrcOut_Mode;
-  } else if (strcmp(op, "source-over") == 0) {
-    mode = SkXfermode::kSrcOver_Mode;  // Default.
-  } else if (strcmp(op, "destination-atop") == 0) {
-    mode = SkXfermode::kDstATop_Mode;
-  } else if (strcmp(op, "destination-in") == 0) {
-    mode = SkXfermode::kDstIn_Mode;
-  } else if (strcmp(op, "destination-out") == 0) {
-    mode = SkXfermode::kDstOut_Mode;
-  } else if (strcmp(op, "destination-over") == 0) {
-    mode = SkXfermode::kDstOver_Mode;
-  } else if (strcmp(op, "lighter") == 0) {
-    mode = SkXfermode::kLighten_Mode;
-  } else if (strcmp(op, "darker") == 0) {
-    mode = SkXfermode::kDarken_Mode;
-  } else if (strcmp(op, "xor") == 0) {
-    mode = SkXfermode::kXor_Mode;
-  } else if (strcmp(op, "copy") == 0) {
-    mode = SkXfermode::kSrc_Mode;
+  static const struct CompositOpToXfermodeMode {
+    const char* mCompositOp;
+    uint8_t m_xfermodeMode;
+  } gMapCompositOpsToXfermodeModes[] = {
+     { "clear",            SkXfermode::kClear_Mode },
+     { "copy",             SkXfermode::kSrc_Mode },
+     { "source-over",      SkXfermode::kSrcOver_Mode },
+     { "source-in",        SkXfermode::kSrcIn_Mode },
+     { "source-out",       SkXfermode::kSrcOut_Mode },
+     { "source-atop",      SkXfermode::kSrcATop_Mode },
+     { "destination-over", SkXfermode::kDstOver_Mode },
+     { "destination-in",   SkXfermode::kDstIn_Mode },
+     { "destination-out",  SkXfermode::kDstOut_Mode },
+     { "destination-atop", SkXfermode::kDstATop_Mode },
+     { "xor",              SkXfermode::kXor_Mode },
+     { "darker",           SkXfermode::kDarken_Mode },
+     { "lighter",          SkXfermode::kPlus_Mode }
+  };
+  for (unsigned i = 0;
+       i < SK_ARRAY_COUNT(gMapCompositOpsToXfermodeModes);
+       i++) {
+    if (strcmp(op, gMapCompositOpsToXfermodeModes[i].mCompositOp) == 0) {
+      mode = (SkXfermode::Mode)gMapCompositOpsToXfermodeModes[i].m_xfermodeMode;
+      paint_.setXfermodeMode(mode);
+      return;
+    }
   }
-  SkXfermode* m = SkXfermode::Create(mode);
-  // It seems we don't need unref() here. Including it causes
-  // a crash. Maybe Skia has a preallocated long-lived set of
-  // instances.
-  paint_.setXfermode(m);
+  LOGE("Unknown CompositeOperator %s\n", op);
+  paint_.setXfermodeMode(SkXfermode::kSrcOver_Mode);  // fall-back
 }
 
 void CanvasState::Arc(float x, float y, float radius,
                       float startAngle, float endAngle,
                       bool antiClockwise) {
   SkRect rect;
   rect.set(x - radius, y - radius, x + radius, y + radius);
   bool doCircle = false;
 
   static float twoPi = 2 * M_PI;
@@ skipping 25 matching lines @@
 int hexDigit(char c) {
   if (c >= '0' && c <= '9') return c - '0';
   if (c <= 'Z') return c - 'A' + 10;
   return c - 'a' + 10;
 }
 
 // Color parser.
 // See http://www.w3.org/TR/CSS21/syndata.html#color-units.
 // There is also another format: hsl(240,100%,100%) (and hsla)
 // TODO(gram): We probably eventually want to use a table rather
-// than a big if statement.
+// than a big if statement; see setGlobalCompositeOperation for
+// an example.
 ColorRGBA CanvasState::GetColor(const char* color) {
   if (color[0] == '#') {
-    int r, g, b;
+    int r = 0, g = 0, b = 0;
     if (strlen(color) == 7) {
       r = hexDigit(color[1]) * 16 + hexDigit(color[2]);
       g = hexDigit(color[3]) * 16 + hexDigit(color[4]);
       b = hexDigit(color[5]) * 16 + hexDigit(color[6]);
     } else if (strlen(color) == 4) {
       r = hexDigit(color[1]) * 16 + hexDigit(color[1]);
       g = hexDigit(color[2]) * 16 + hexDigit(color[2]);
       b = hexDigit(color[3]) * 16 + hexDigit(color[3]);
     }
     return ColorRGBA(r, g, b);
@@ skipping 58 matching lines @@
   if (sw < 0) sw = bm.width();
   if (dw < 0) dw = bm.width();
   if (sh < 0) sh = bm.height();
   if (dh < 0) dh = bm.height();
   SkIRect src = SkIRect::MakeXYWH(sx, sy, sw, sh);
   SkRect dst = SkRect::MakeXYWH(dx, dy, dw, dh);
   LOGI("DrawImage(_,%d,%d,%d,%d,%d,%d,%d,%d)", sx, sy, sw, sh, dx, dy, dw, dh);
   canvas_->drawBitmapRect(bm, &src, dst);
 }