SkBitmap now really stores SkImageInfo -- config is just a ruse

include/core/SkImageInfo.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkImageInfo_DEFINED
 #define SkImageInfo_DEFINED
 
-#include "SkTypes.h"
+#include "SkMath.h"
 #include "SkSize.h"
 
 class SkWriteBuffer;
 class SkReadBuffer;
 
 /**
  *  Describes how to interpret the alpha compoent of a pixel.
  */
 enum SkAlphaType {
     /**
@@ skipping 30 matching lines @@
 };
 
 static inline bool SkAlphaTypeIsOpaque(SkAlphaType at) {
     SK_COMPILE_ASSERT(kIgnore_SkAlphaType < kOpaque_SkAlphaType, bad_alphatype_order);
     SK_COMPILE_ASSERT(kPremul_SkAlphaType > kOpaque_SkAlphaType, bad_alphatype_order);
     SK_COMPILE_ASSERT(kUnpremul_SkAlphaType > kOpaque_SkAlphaType, bad_alphatype_order);
 
     return (unsigned)at <= kOpaque_SkAlphaType;
 }
 
+static inline bool SkAlphaTypeIsValid(unsigned value) {

[scroggo, 2014/02/10 21:45:44]

Does this need to be unsigned? It seems like all the callers pass in an
SkAlphaType (similar question for SkColorTypeIsValid)?

[reed1, 2014/02/10 21:59:51]

Yea, I wanted to explicitly not let the compiler make this a no-op. If I call
the param the enum, then it seems like it could do that.

+    return value >= kIgnore_SkAlphaType && value <= kLastEnum_SkAlphaType;
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 /**
  *  Describes how to interpret the components of a pixel.
  */
 enum SkColorType {
+    kUnknown_SkColorType,
     kAlpha_8_SkColorType,
     kRGB_565_SkColorType,
     kARGB_4444_SkColorType,
     kRGBA_8888_SkColorType,
     kBGRA_8888_SkColorType,
     kIndex_8_SkColorType,
 
     kLastEnum_SkColorType = kIndex_8_SkColorType,
 
 #if SK_PMCOLOR_BYTE_ORDER(B,G,R,A)
     kPMColor_SkColorType = kBGRA_8888_SkColorType
 #elif SK_PMCOLOR_BYTE_ORDER(R,G,B,A)
     kPMColor_SkColorType = kRGBA_8888_SkColorType
 #else
 #error "SK_*32_SHFIT values must correspond to BGRA or RGBA byte order"
 #endif
 };
 
 static int SkColorTypeBytesPerPixel(SkColorType ct) {
     static const uint8_t gSize[] = {
+        0,  // Unknown
         1,  // Alpha_8
         2,  // RGB_565
         2,  // ARGB_4444
         4,  // RGBA_8888
         4,  // BGRA_8888
         1,  // kIndex_8
     };
     SK_COMPILE_ASSERT(SK_ARRAY_COUNT(gSize) == (size_t)(kLastEnum_SkColorType + 1),
                       size_mismatch_with_SkColorType_enum);
 
     SkASSERT((size_t)ct < SK_ARRAY_COUNT(gSize));
     return gSize[ct];
 }
 
+static inline size_t SkColorTypeMinRowBytes(SkColorType ct, int width) {
+    return width * SkColorTypeBytesPerPixel(ct);
+}
+
+static inline bool SkColorTypeIsValid(unsigned value) {
+    return value >= kUnknown_SkColorType && value <= kLastEnum_SkColorType;
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 /**
  *  Describe an image's dimensions and pixel type.
  */
 struct SkImageInfo {
     int         fWidth;
     int         fHeight;
     SkColorType fColorType;
     SkAlphaType fAlphaType;
@@ skipping 40 matching lines @@
 
     static SkImageInfo MakeA8(int width, int height) {
         SkASSERT(width >= 0);
         SkASSERT(height >= 0);
         SkImageInfo info = {
             width, height, kAlpha_8_SkColorType, kPremul_SkAlphaType
         };
         return info;
     }
 
+    int width() const { return fWidth; }

[scroggo, 2014/02/10 21:45:44]

I find it interesting that we have const accessors to fields that are publicly
accessible. Is the plan to make fWidth etc private?

[reed1, 2014/02/10 21:59:51]

Yes, I want to make them private.

+    int height() const { return fHeight; }
+    SkColorType colorType() const { return fColorType; }
+    SkAlphaType alphaType() const { return fAlphaType; }
+
+    bool isEmpty() const { return fWidth <= 0 || fHeight <= 0; }
+
     bool isOpaque() const {
         return SkAlphaTypeIsOpaque(fAlphaType);
     }
 
+    SkISize dimensions() const { return SkISize::Make(fWidth, fHeight); }
+
     int bytesPerPixel() const {
         return SkColorTypeBytesPerPixel(fColorType);
     }
 
+    uint64_t minRowBytes64() const {
+        return sk_64_mul(fWidth, this->bytesPerPixel());
+    }
+    
     size_t minRowBytes() const {
-        return fWidth * this->bytesPerPixel();
+        return (size_t)this->minRowBytes64();
     }
-
+    
     bool operator==(const SkImageInfo& other) const {
         return 0 == memcmp(this, &other, sizeof(other));
     }
     bool operator!=(const SkImageInfo& other) const {
         return 0 != memcmp(this, &other, sizeof(other));
     }
 
     void unflatten(SkReadBuffer&);
     void flatten(SkWriteBuffer&) const;
 
-    size_t getSafeSize(size_t rowBytes) const {
+    int64_t getSafeSize64(size_t rowBytes) const {
         if (0 == fHeight) {
             return 0;
         }
-        return (fHeight - 1) * rowBytes + fWidth * this->bytesPerPixel();
+        return sk_64_mul(fHeight - 1, rowBytes) + fWidth * this->bytesPerPixel();
     }
+
+    size_t getSafeSize(size_t rowBytes) const {
+        return (size_t)this->getSafeSize64(rowBytes);
+    }
+
+    bool validRowBytes(size_t rowBytes) const {
+        uint64_t rb = sk_64_mul(fWidth, this->bytesPerPixel());
+        return rowBytes >= rb;
+    }
+
+    SkDEBUGCODE(void validate() const;)
 };
 
 #endif