diff options
author | msarett <msarett@google.com> | 2015-11-13 06:11:09 -0800 |
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committer | Commit bot <commit-bot@chromium.org> | 2015-11-13 06:11:09 -0800 |
commit | 506e19a4c8395178e8da81576b3c37616593e560 (patch) | |
tree | 0877d660a91ef6322059269e7020988459e91ded /src/android/SkBitmapRegionDecoderPriv.h | |
parent | 9c8605144a0f15e3e69a4e1dcd5d3e63f339380e (diff) |
Move SkBitmapRegionDecoder to include/android and src/android
This will expose the BitmapRegionDecoder API as a public include
and move the implementation to src.
This makes this code more naturally exposed in Android and easier
to test in DM and nanobench.
BUG=skia:
Review URL: https://codereview.chromium.org/1438873002
Diffstat (limited to 'src/android/SkBitmapRegionDecoderPriv.h')
-rw-r--r-- | src/android/SkBitmapRegionDecoderPriv.h | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/src/android/SkBitmapRegionDecoderPriv.h b/src/android/SkBitmapRegionDecoderPriv.h new file mode 100644 index 0000000000..d7423b05fd --- /dev/null +++ b/src/android/SkBitmapRegionDecoderPriv.h @@ -0,0 +1,63 @@ +/* + * Copyright 2015 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#ifndef SkBitmapRegionDecoderPriv_DEFINED +#define SkBitmapRegionDecoderPriv_DEFINED + +inline float get_scale_from_sample_size(uint32_t sampleSize) { + return 1.0f / (float) sampleSize; +} + +enum SubsetType { + kFullyInside_SubsetType, + kPartiallyInside_SubsetType, + kOutside_SubsetType, +}; + +/* + * Corrects image subset offsets and dimensions in order to perform a valid decode. + * Also indicates if the image subset should be placed at an offset within the + * output bitmap. + * + * Values of output variables are undefined if the SubsetType is kInvalid. + * + * @param imageDims Original image dimensions. + * @param subset As input, the subset that the client requested. + * As output, the image subset that we will decode. + * @param outX The left offset of the image subset within the output bitmap. + * @param outY The top offset of the image subset within the output bitmap. + * + * @return An indication of how the subset is contained in the image. + * If the return value is kInvalid, values of output variables are undefined. + */ +inline SubsetType adjust_subset_rect(const SkISize& imageDims, SkIRect* subset, int* outX, + int* outY) { + // These must be at least zero, we can't start decoding the image at a negative coordinate. + int left = SkTMax(0, subset->fLeft); + int top = SkTMax(0, subset->fTop); + + // If input offsets are less than zero, we decode to an offset location in the output bitmap. + *outX = left - subset->fLeft; + *outY = top - subset->fTop; + + // Make sure we don't decode pixels past the edge of the image or past the edge of the subset. + int width = SkTMin(imageDims.width() - left, subset->width() - *outX); + int height = SkTMin(imageDims.height() - top, subset->height() - *outY); + if (width <= 0 || height <= 0) { + return SubsetType::kOutside_SubsetType; + } + + subset->setXYWH(left, top, width, height); + if ((*outX != 0) || (*outY != 0) || (width != subset->width()) || + (height != subset->height())) { + return SubsetType::kPartiallyInside_SubsetType; + } + + return SubsetType::kFullyInside_SubsetType; +} + +#endif // SkBitmapRegionDecoderPriv_DEFINED |