8a9618aea2
1. Rename `CelGetFrameStart` to `CelGetFrame`, in line with the other 2 functions with the same name and load the `uint32_t` safely. 2. Remove redundant `FrameHeader`, simply use `LoadLE16`. 3. Document all the functions.
57 lines
1.8 KiB
C++
57 lines
1.8 KiB
C++
#pragma once
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#include <cstdint>
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#include <cstring>
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#include <SDL_endian.h>
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#include "utils/endian.hpp"
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#include "utils/stdcompat/cstddef.hpp"
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namespace devilution {
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/**
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* Returns the pointer to the start of the frame data (often a header).
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*/
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inline byte *CelGetFrame(byte *data, int frame)
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{
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const std::uint32_t begin = LoadLE32(&data[frame * sizeof(std::uint32_t)]);
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return &data[begin];
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}
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/**
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* Returns the pointer to the start of the frame data (often a header) and sets `frameSize` to the size of the data in bytes.
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*/
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inline byte *CelGetFrame(byte *data, int frame, int *frameSize)
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{
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const std::uint32_t begin = LoadLE32(&data[frame * sizeof(std::uint32_t)]);
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*frameSize = static_cast<int>(LoadLE32(&data[(frame + 1) * sizeof(std::uint32_t)]) - begin);
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return &data[begin];
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}
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/**
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* Returns the pointer to the start of the frame data (often a header) and sets `frameSize` to the size of the data in bytes.
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*/
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inline const byte *CelGetFrame(const byte *data, int frame, int *frameSize)
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{
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const std::uint32_t begin = LoadLE32(&data[frame * sizeof(std::uint32_t)]);
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*frameSize = static_cast<int>(LoadLE32(&data[(frame + 1) * sizeof(std::uint32_t)]) - begin);
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return &data[begin];
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}
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/**
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* Returns the pointer to the start of the frame's pixel data and sets `frameSize` to the size of the data in bytes.
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*/
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inline const byte *CelGetFrameClipped(const byte *data, int frame, int *frameSize)
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{
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const byte *frameData = CelGetFrame(data, frame, frameSize);
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// The frame begins with a header that consists of 5 little-endian 16-bit integers
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// pointing to the start of the pixel data for rows 0, 32, 64, 96, and 128.
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const std::uint16_t begin = LoadLE16(frameData);
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*frameSize -= begin;
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return &frameData[begin];
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}
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} // namespace devilution
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