1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/include/core/SkImageInfo.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,229 @@
1.4 +/*
1.5 + * Copyright 2013 Google Inc.
1.6 + *
1.7 + * Use of this source code is governed by a BSD-style license that can be
1.8 + * found in the LICENSE file.
1.9 + */
1.10 +
1.11 +#ifndef SkImageInfo_DEFINED
1.12 +#define SkImageInfo_DEFINED
1.13 +
1.14 +#include "SkMath.h"
1.15 +#include "SkSize.h"
1.16 +
1.17 +class SkWriteBuffer;
1.18 +class SkReadBuffer;
1.19 +
1.20 +/**
1.21 + * Describes how to interpret the alpha compoent of a pixel.
1.22 + */
1.23 +enum SkAlphaType {
1.24 + /**
1.25 + * All pixels should be treated as opaque, regardless of the value stored
1.26 + * in their alpha field. Used for legacy images that wrote 0 or garbarge
1.27 + * in their alpha field, but intended the RGB to be treated as opaque.
1.28 + */
1.29 + kIgnore_SkAlphaType,
1.30 +
1.31 + /**
1.32 + * All pixels are stored as opaque. This differs slightly from kIgnore in
1.33 + * that kOpaque has correct "opaque" values stored in the pixels, while
1.34 + * kIgnore may not, but in both cases the caller should treat the pixels
1.35 + * as opaque.
1.36 + */
1.37 + kOpaque_SkAlphaType,
1.38 +
1.39 + /**
1.40 + * All pixels have their alpha premultiplied in their color components.
1.41 + * This is the natural format for the rendering target pixels.
1.42 + */
1.43 + kPremul_SkAlphaType,
1.44 +
1.45 + /**
1.46 + * All pixels have their color components stored without any regard to the
1.47 + * alpha. e.g. this is the default configuration for PNG images.
1.48 + *
1.49 + * This alpha-type is ONLY supported for input images. Rendering cannot
1.50 + * generate this on output.
1.51 + */
1.52 + kUnpremul_SkAlphaType,
1.53 +
1.54 + kLastEnum_SkAlphaType = kUnpremul_SkAlphaType
1.55 +};
1.56 +
1.57 +static inline bool SkAlphaTypeIsOpaque(SkAlphaType at) {
1.58 + SK_COMPILE_ASSERT(kIgnore_SkAlphaType < kOpaque_SkAlphaType, bad_alphatype_order);
1.59 + SK_COMPILE_ASSERT(kPremul_SkAlphaType > kOpaque_SkAlphaType, bad_alphatype_order);
1.60 + SK_COMPILE_ASSERT(kUnpremul_SkAlphaType > kOpaque_SkAlphaType, bad_alphatype_order);
1.61 +
1.62 + return (unsigned)at <= kOpaque_SkAlphaType;
1.63 +}
1.64 +
1.65 +static inline bool SkAlphaTypeIsValid(unsigned value) {
1.66 + return value <= kLastEnum_SkAlphaType;
1.67 +}
1.68 +
1.69 +///////////////////////////////////////////////////////////////////////////////
1.70 +
1.71 +/**
1.72 + * Describes how to interpret the components of a pixel.
1.73 + */
1.74 +enum SkColorType {
1.75 + kUnknown_SkColorType,
1.76 + kAlpha_8_SkColorType,
1.77 + kRGB_565_SkColorType,
1.78 + kARGB_4444_SkColorType,
1.79 + kRGBA_8888_SkColorType,
1.80 + kBGRA_8888_SkColorType,
1.81 + kIndex_8_SkColorType,
1.82 +
1.83 + kLastEnum_SkColorType = kIndex_8_SkColorType,
1.84 +
1.85 +#if SK_PMCOLOR_BYTE_ORDER(B,G,R,A)
1.86 + kPMColor_SkColorType = kBGRA_8888_SkColorType
1.87 +#elif SK_PMCOLOR_BYTE_ORDER(R,G,B,A)
1.88 + kPMColor_SkColorType = kRGBA_8888_SkColorType
1.89 +#else
1.90 +#error "SK_*32_SHFIT values must correspond to BGRA or RGBA byte order"
1.91 +#endif
1.92 +};
1.93 +
1.94 +static int SkColorTypeBytesPerPixel(SkColorType ct) {
1.95 + static const uint8_t gSize[] = {
1.96 + 0, // Unknown
1.97 + 1, // Alpha_8
1.98 + 2, // RGB_565
1.99 + 2, // ARGB_4444
1.100 + 4, // RGBA_8888
1.101 + 4, // BGRA_8888
1.102 + 1, // kIndex_8
1.103 + };
1.104 + SK_COMPILE_ASSERT(SK_ARRAY_COUNT(gSize) == (size_t)(kLastEnum_SkColorType + 1),
1.105 + size_mismatch_with_SkColorType_enum);
1.106 +
1.107 + SkASSERT((size_t)ct < SK_ARRAY_COUNT(gSize));
1.108 + return gSize[ct];
1.109 +}
1.110 +
1.111 +static inline size_t SkColorTypeMinRowBytes(SkColorType ct, int width) {
1.112 + return width * SkColorTypeBytesPerPixel(ct);
1.113 +}
1.114 +
1.115 +static inline bool SkColorTypeIsValid(unsigned value) {
1.116 + return value <= kLastEnum_SkColorType;
1.117 +}
1.118 +
1.119 +///////////////////////////////////////////////////////////////////////////////
1.120 +
1.121 +/**
1.122 + * Describe an image's dimensions and pixel type.
1.123 + */
1.124 +struct SkImageInfo {
1.125 + int fWidth;
1.126 + int fHeight;
1.127 + SkColorType fColorType;
1.128 + SkAlphaType fAlphaType;
1.129 +
1.130 + static SkImageInfo Make(int width, int height, SkColorType ct, SkAlphaType at) {
1.131 + SkImageInfo info = {
1.132 + width, height, ct, at
1.133 + };
1.134 + return info;
1.135 + }
1.136 +
1.137 + /**
1.138 + * Sets colortype to the native ARGB32 type.
1.139 + */
1.140 + static SkImageInfo MakeN32(int width, int height, SkAlphaType at) {
1.141 + SkImageInfo info = {
1.142 + width, height, kPMColor_SkColorType, at
1.143 + };
1.144 + return info;
1.145 + }
1.146 +
1.147 + /**
1.148 + * Sets colortype to the native ARGB32 type, and the alphatype to premul.
1.149 + */
1.150 + static SkImageInfo MakeN32Premul(int width, int height) {
1.151 + SkImageInfo info = {
1.152 + width, height, kPMColor_SkColorType, kPremul_SkAlphaType
1.153 + };
1.154 + return info;
1.155 + }
1.156 +
1.157 + /**
1.158 + * Sets colortype to the native ARGB32 type, and the alphatype to premul.
1.159 + */
1.160 + static SkImageInfo MakeN32Premul(const SkISize& size) {
1.161 + return MakeN32Premul(size.width(), size.height());
1.162 + }
1.163 +
1.164 + static SkImageInfo MakeA8(int width, int height) {
1.165 + SkImageInfo info = {
1.166 + width, height, kAlpha_8_SkColorType, kPremul_SkAlphaType
1.167 + };
1.168 + return info;
1.169 + }
1.170 +
1.171 + static SkImageInfo MakeUnknown(int width, int height) {
1.172 + SkImageInfo info = {
1.173 + width, height, kUnknown_SkColorType, kIgnore_SkAlphaType
1.174 + };
1.175 + return info;
1.176 + }
1.177 +
1.178 + int width() const { return fWidth; }
1.179 + int height() const { return fHeight; }
1.180 + SkColorType colorType() const { return fColorType; }
1.181 + SkAlphaType alphaType() const { return fAlphaType; }
1.182 +
1.183 + bool isEmpty() const { return fWidth <= 0 || fHeight <= 0; }
1.184 +
1.185 + bool isOpaque() const {
1.186 + return SkAlphaTypeIsOpaque(fAlphaType);
1.187 + }
1.188 +
1.189 + SkISize dimensions() const { return SkISize::Make(fWidth, fHeight); }
1.190 +
1.191 + int bytesPerPixel() const {
1.192 + return SkColorTypeBytesPerPixel(fColorType);
1.193 + }
1.194 +
1.195 + uint64_t minRowBytes64() const {
1.196 + return sk_64_mul(fWidth, this->bytesPerPixel());
1.197 + }
1.198 +
1.199 + size_t minRowBytes() const {
1.200 + return (size_t)this->minRowBytes64();
1.201 + }
1.202 +
1.203 + bool operator==(const SkImageInfo& other) const {
1.204 + return 0 == memcmp(this, &other, sizeof(other));
1.205 + }
1.206 + bool operator!=(const SkImageInfo& other) const {
1.207 + return 0 != memcmp(this, &other, sizeof(other));
1.208 + }
1.209 +
1.210 + void unflatten(SkReadBuffer&);
1.211 + void flatten(SkWriteBuffer&) const;
1.212 +
1.213 + int64_t getSafeSize64(size_t rowBytes) const {
1.214 + if (0 == fHeight) {
1.215 + return 0;
1.216 + }
1.217 + return sk_64_mul(fHeight - 1, rowBytes) + fWidth * this->bytesPerPixel();
1.218 + }
1.219 +
1.220 + size_t getSafeSize(size_t rowBytes) const {
1.221 + return (size_t)this->getSafeSize64(rowBytes);
1.222 + }
1.223 +
1.224 + bool validRowBytes(size_t rowBytes) const {
1.225 + uint64_t rb = sk_64_mul(fWidth, this->bytesPerPixel());
1.226 + return rowBytes >= rb;
1.227 + }
1.228 +
1.229 + SkDEBUGCODE(void validate() const;)
1.230 +};
1.231 +
1.232 +#endif
