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+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkEncodedInfo_DEFINED
+#define SkEncodedInfo_DEFINED
+
+#include "SkImageInfo.h"
+
+class SkColorSpace;
+
+struct SkEncodedInfo {
+public:
+
+ enum Alpha {
+ kOpaque_Alpha,
+ kUnpremul_Alpha,
+
+ // Each pixel is either fully opaque or fully transparent.
+ // There is no difference between requesting kPremul or kUnpremul.
+ kBinary_Alpha,
+ };
+
+ /*
+ * We strive to make the number of components per pixel obvious through
+ * our naming conventions.
+ * Ex: kRGB has 3 components. kRGBA has 4 components.
+ *
+ * This sometimes results in redundant Alpha and Color information.
+ * Ex: kRGB images must also be kOpaque.
+ */
+ enum Color {
+ // PNG, WBMP
+ kGray_Color,
+
+ // PNG
+ kGrayAlpha_Color,
+
+ // PNG, GIF, BMP
+ kPalette_Color,
+
+ // PNG, RAW
+ kRGB_Color,
+ kRGBA_Color,
+
+ // BMP
+ kBGR_Color,
+ kBGRX_Color,
+ kBGRA_Color,
+
+ // JPEG, WEBP
+ kYUV_Color,
+
+ // WEBP
+ kYUVA_Color,
+
+ // JPEG
+ // Photoshop actually writes inverted CMYK data into JPEGs, where zero
+ // represents 100% ink coverage. For this reason, we treat CMYK JPEGs
+ // as having inverted CMYK. libjpeg-turbo warns that this may break
+ // other applications, but the CMYK JPEGs we see on the web expect to
+ // be treated as inverted CMYK.
+ kInvertedCMYK_Color,
+ kYCCK_Color,
+ };
+
+ static SkEncodedInfo Make(Color color, Alpha alpha, int bitsPerComponent) {
+ SkASSERT(1 == bitsPerComponent ||
+ 2 == bitsPerComponent ||
+ 4 == bitsPerComponent ||
+ 8 == bitsPerComponent ||
+ 16 == bitsPerComponent);
+
+ switch (color) {
+ case kGray_Color:
+ SkASSERT(kOpaque_Alpha == alpha);
+ break;
+ case kGrayAlpha_Color:
+ SkASSERT(kOpaque_Alpha != alpha);
+ break;
+ case kPalette_Color:
+ SkASSERT(16 != bitsPerComponent);
+ break;
+ case kRGB_Color:
+ case kBGR_Color:
+ case kBGRX_Color:
+ SkASSERT(kOpaque_Alpha == alpha);
+ SkASSERT(bitsPerComponent >= 8);
+ break;
+ case kYUV_Color:
+ case kInvertedCMYK_Color:
+ case kYCCK_Color:
+ SkASSERT(kOpaque_Alpha == alpha);
+ SkASSERT(8 == bitsPerComponent);
+ break;
+ case kRGBA_Color:
+ SkASSERT(kOpaque_Alpha != alpha);
+ SkASSERT(bitsPerComponent >= 8);
+ break;
+ case kBGRA_Color:
+ case kYUVA_Color:
+ SkASSERT(kOpaque_Alpha != alpha);
+ SkASSERT(8 == bitsPerComponent);
+ break;
+ default:
+ SkASSERT(false);
+ break;
+ }
+
+ return SkEncodedInfo(color, alpha, bitsPerComponent);
+ }
+
+ /*
+ * Returns an SkImageInfo with Skia color and alpha types that are the
+ * closest possible match to the encoded info.
+ */
+ SkImageInfo makeImageInfo(int width, int height, sk_sp<SkColorSpace> colorSpace) const {
+ auto ct = kGray_Color == fColor ? kGray_8_SkColorType :
+ kN32_SkColorType ;
+ auto alpha = kOpaque_Alpha == fAlpha ? kOpaque_SkAlphaType
+ : kUnpremul_SkAlphaType;
+ return SkImageInfo::Make(width, height, ct, alpha, std::move(colorSpace));
+ }
+
+ Color color() const { return fColor; }
+ Alpha alpha() const { return fAlpha; }
+ bool opaque() const { return fAlpha == kOpaque_Alpha; }
+
+ uint8_t bitsPerComponent() const { return fBitsPerComponent; }
+
+ uint8_t bitsPerPixel() const {
+ switch (fColor) {
+ case kGray_Color:
+ return fBitsPerComponent;
+ case kGrayAlpha_Color:
+ return 2 * fBitsPerComponent;
+ case kPalette_Color:
+ return fBitsPerComponent;
+ case kRGB_Color:
+ case kBGR_Color:
+ case kYUV_Color:
+ return 3 * fBitsPerComponent;
+ case kRGBA_Color:
+ case kBGRA_Color:
+ case kBGRX_Color:
+ case kYUVA_Color:
+ case kInvertedCMYK_Color:
+ case kYCCK_Color:
+ return 4 * fBitsPerComponent;
+ default:
+ SkASSERT(false);
+ return 0;
+ }
+ }
+
+private:
+
+ SkEncodedInfo(Color color, Alpha alpha, uint8_t bitsPerComponent)
+ : fColor(color)
+ , fAlpha(alpha)
+ , fBitsPerComponent(bitsPerComponent)
+ {}
+
+ Color fColor;
+ Alpha fAlpha;
+ uint8_t fBitsPerComponent;
+};
+
+#endif