michael@0: /*
michael@0:  * Copyright 2013 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #ifndef SkImageInfo_DEFINED
michael@0: #define SkImageInfo_DEFINED
michael@0: 
michael@0: #include "SkMath.h"
michael@0: #include "SkSize.h"
michael@0: 
michael@0: class SkWriteBuffer;
michael@0: class SkReadBuffer;
michael@0: 
michael@0: /**
michael@0:  *  Describes how to interpret the alpha compoent of a pixel.
michael@0:  */
michael@0: enum SkAlphaType {
michael@0:     /**
michael@0:      *  All pixels should be treated as opaque, regardless of the value stored
michael@0:      *  in their alpha field. Used for legacy images that wrote 0 or garbarge
michael@0:      *  in their alpha field, but intended the RGB to be treated as opaque.
michael@0:      */
michael@0:     kIgnore_SkAlphaType,
michael@0: 
michael@0:     /**
michael@0:      *  All pixels are stored as opaque. This differs slightly from kIgnore in
michael@0:      *  that kOpaque has correct "opaque" values stored in the pixels, while
michael@0:      *  kIgnore may not, but in both cases the caller should treat the pixels
michael@0:      *  as opaque.
michael@0:      */
michael@0:     kOpaque_SkAlphaType,
michael@0: 
michael@0:     /**
michael@0:      *  All pixels have their alpha premultiplied in their color components.
michael@0:      *  This is the natural format for the rendering target pixels.
michael@0:      */
michael@0:     kPremul_SkAlphaType,
michael@0: 
michael@0:     /**
michael@0:      *  All pixels have their color components stored without any regard to the
michael@0:      *  alpha. e.g. this is the default configuration for PNG images.
michael@0:      *
michael@0:      *  This alpha-type is ONLY supported for input images. Rendering cannot
michael@0:      *  generate this on output.
michael@0:      */
michael@0:     kUnpremul_SkAlphaType,
michael@0: 
michael@0:     kLastEnum_SkAlphaType = kUnpremul_SkAlphaType
michael@0: };
michael@0: 
michael@0: static inline bool SkAlphaTypeIsOpaque(SkAlphaType at) {
michael@0:     SK_COMPILE_ASSERT(kIgnore_SkAlphaType < kOpaque_SkAlphaType, bad_alphatype_order);
michael@0:     SK_COMPILE_ASSERT(kPremul_SkAlphaType > kOpaque_SkAlphaType, bad_alphatype_order);
michael@0:     SK_COMPILE_ASSERT(kUnpremul_SkAlphaType > kOpaque_SkAlphaType, bad_alphatype_order);
michael@0: 
michael@0:     return (unsigned)at <= kOpaque_SkAlphaType;
michael@0: }
michael@0: 
michael@0: static inline bool SkAlphaTypeIsValid(unsigned value) {
michael@0:     return value <= kLastEnum_SkAlphaType;
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: /**
michael@0:  *  Describes how to interpret the components of a pixel.
michael@0:  */
michael@0: enum SkColorType {
michael@0:     kUnknown_SkColorType,
michael@0:     kAlpha_8_SkColorType,
michael@0:     kRGB_565_SkColorType,
michael@0:     kARGB_4444_SkColorType,
michael@0:     kRGBA_8888_SkColorType,
michael@0:     kBGRA_8888_SkColorType,
michael@0:     kIndex_8_SkColorType,
michael@0: 
michael@0:     kLastEnum_SkColorType = kIndex_8_SkColorType,
michael@0: 
michael@0: #if SK_PMCOLOR_BYTE_ORDER(B,G,R,A)
michael@0:     kPMColor_SkColorType = kBGRA_8888_SkColorType
michael@0: #elif SK_PMCOLOR_BYTE_ORDER(R,G,B,A)
michael@0:     kPMColor_SkColorType = kRGBA_8888_SkColorType
michael@0: #else
michael@0: #error "SK_*32_SHFIT values must correspond to BGRA or RGBA byte order"
michael@0: #endif
michael@0: };
michael@0: 
michael@0: static int SkColorTypeBytesPerPixel(SkColorType ct) {
michael@0:     static const uint8_t gSize[] = {
michael@0:         0,  // Unknown
michael@0:         1,  // Alpha_8
michael@0:         2,  // RGB_565
michael@0:         2,  // ARGB_4444
michael@0:         4,  // RGBA_8888
michael@0:         4,  // BGRA_8888
michael@0:         1,  // kIndex_8
michael@0:     };
michael@0:     SK_COMPILE_ASSERT(SK_ARRAY_COUNT(gSize) == (size_t)(kLastEnum_SkColorType + 1),
michael@0:                       size_mismatch_with_SkColorType_enum);
michael@0: 
michael@0:     SkASSERT((size_t)ct < SK_ARRAY_COUNT(gSize));
michael@0:     return gSize[ct];
michael@0: }
michael@0: 
michael@0: static inline size_t SkColorTypeMinRowBytes(SkColorType ct, int width) {
michael@0:     return width * SkColorTypeBytesPerPixel(ct);
michael@0: }
michael@0: 
michael@0: static inline bool SkColorTypeIsValid(unsigned value) {
michael@0:     return value <= kLastEnum_SkColorType;
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: /**
michael@0:  *  Describe an image's dimensions and pixel type.
michael@0:  */
michael@0: struct SkImageInfo {
michael@0:     int         fWidth;
michael@0:     int         fHeight;
michael@0:     SkColorType fColorType;
michael@0:     SkAlphaType fAlphaType;
michael@0: 
michael@0:     static SkImageInfo Make(int width, int height, SkColorType ct, SkAlphaType at) {
michael@0:         SkImageInfo info = {
michael@0:             width, height, ct, at
michael@0:         };
michael@0:         return info;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      *  Sets colortype to the native ARGB32 type.
michael@0:      */
michael@0:     static SkImageInfo MakeN32(int width, int height, SkAlphaType at) {
michael@0:         SkImageInfo info = {
michael@0:             width, height, kPMColor_SkColorType, at
michael@0:         };
michael@0:         return info;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      *  Sets colortype to the native ARGB32 type, and the alphatype to premul.
michael@0:      */
michael@0:     static SkImageInfo MakeN32Premul(int width, int height) {
michael@0:         SkImageInfo info = {
michael@0:             width, height, kPMColor_SkColorType, kPremul_SkAlphaType
michael@0:         };
michael@0:         return info;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      *  Sets colortype to the native ARGB32 type, and the alphatype to premul.
michael@0:      */
michael@0:     static SkImageInfo MakeN32Premul(const SkISize& size) {
michael@0:         return MakeN32Premul(size.width(), size.height());
michael@0:     }
michael@0: 
michael@0:     static SkImageInfo MakeA8(int width, int height) {
michael@0:         SkImageInfo info = {
michael@0:             width, height, kAlpha_8_SkColorType, kPremul_SkAlphaType
michael@0:         };
michael@0:         return info;
michael@0:     }
michael@0: 
michael@0:     static SkImageInfo MakeUnknown(int width, int height) {
michael@0:         SkImageInfo info = {
michael@0:             width, height, kUnknown_SkColorType, kIgnore_SkAlphaType
michael@0:         };
michael@0:         return info;
michael@0:     }
michael@0: 
michael@0:     int width() const { return fWidth; }
michael@0:     int height() const { return fHeight; }
michael@0:     SkColorType colorType() const { return fColorType; }
michael@0:     SkAlphaType alphaType() const { return fAlphaType; }
michael@0: 
michael@0:     bool isEmpty() const { return fWidth <= 0 || fHeight <= 0; }
michael@0: 
michael@0:     bool isOpaque() const {
michael@0:         return SkAlphaTypeIsOpaque(fAlphaType);
michael@0:     }
michael@0: 
michael@0:     SkISize dimensions() const { return SkISize::Make(fWidth, fHeight); }
michael@0: 
michael@0:     int bytesPerPixel() const {
michael@0:         return SkColorTypeBytesPerPixel(fColorType);
michael@0:     }
michael@0: 
michael@0:     uint64_t minRowBytes64() const {
michael@0:         return sk_64_mul(fWidth, this->bytesPerPixel());
michael@0:     }
michael@0: 
michael@0:     size_t minRowBytes() const {
michael@0:         return (size_t)this->minRowBytes64();
michael@0:     }
michael@0: 
michael@0:     bool operator==(const SkImageInfo& other) const {
michael@0:         return 0 == memcmp(this, &other, sizeof(other));
michael@0:     }
michael@0:     bool operator!=(const SkImageInfo& other) const {
michael@0:         return 0 != memcmp(this, &other, sizeof(other));
michael@0:     }
michael@0: 
michael@0:     void unflatten(SkReadBuffer&);
michael@0:     void flatten(SkWriteBuffer&) const;
michael@0: 
michael@0:     int64_t getSafeSize64(size_t rowBytes) const {
michael@0:         if (0 == fHeight) {
michael@0:             return 0;
michael@0:         }
michael@0:         return sk_64_mul(fHeight - 1, rowBytes) + fWidth * this->bytesPerPixel();
michael@0:     }
michael@0: 
michael@0:     size_t getSafeSize(size_t rowBytes) const {
michael@0:         return (size_t)this->getSafeSize64(rowBytes);
michael@0:     }
michael@0: 
michael@0:     bool validRowBytes(size_t rowBytes) const {
michael@0:         uint64_t rb = sk_64_mul(fWidth, this->bytesPerPixel());
michael@0:         return rowBytes >= rb;
michael@0:     }
michael@0: 
michael@0:     SkDEBUGCODE(void validate() const;)
michael@0: };
michael@0: 
michael@0: #endif