410 lines
11 KiB
C++
410 lines
11 KiB
C++
/* $Id$ */
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/*
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* This file is part of OpenTTD.
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* OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
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* OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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* See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
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*/
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/** @file bmp.cpp Read and write support for bmps. */
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#include "stdafx.h"
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#include "bmp.h"
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#include "core/bitmath_func.hpp"
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#include "core/alloc_func.hpp"
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#include "core/mem_func.hpp"
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void BmpInitializeBuffer(BmpBuffer *buffer, FILE *file)
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{
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buffer->pos = -1;
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buffer->file = file;
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buffer->read = 0;
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buffer->real_pos = ftell(file);
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}
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static inline void AdvanceBuffer(BmpBuffer *buffer)
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{
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buffer->read = (int)fread(buffer->data, 1, BMP_BUFFER_SIZE, buffer->file);
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buffer->pos = 0;
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}
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static inline bool EndOfBuffer(BmpBuffer *buffer)
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{
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if (buffer->pos == buffer->read || buffer->pos < 0) AdvanceBuffer(buffer);
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return buffer->pos == buffer->read;
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}
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static inline byte ReadByte(BmpBuffer *buffer)
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{
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if (buffer->pos == buffer->read || buffer->pos < 0) AdvanceBuffer(buffer);
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buffer->real_pos++;
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return buffer->data[buffer->pos++];
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}
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static inline uint16 ReadWord(BmpBuffer *buffer)
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{
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uint16 var = ReadByte(buffer);
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return var | (ReadByte(buffer) << 8);
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}
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static inline uint32 ReadDword(BmpBuffer *buffer)
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{
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uint32 var = ReadWord(buffer);
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return var | (ReadWord(buffer) << 16);
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}
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static inline void SkipBytes(BmpBuffer *buffer, int bytes)
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{
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int i;
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for (i = 0; i < bytes; i++) ReadByte(buffer);
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}
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static inline void SetStreamOffset(BmpBuffer *buffer, int offset)
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{
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fseek(buffer->file, offset, SEEK_SET);
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buffer->pos = -1;
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buffer->real_pos = offset;
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AdvanceBuffer(buffer);
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}
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/**
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* Reads a 1 bpp uncompressed bitmap
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* The bitmap is converted to a 8 bpp bitmap
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*/
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static inline bool BmpRead1(BmpBuffer *buffer, BmpInfo *info, BmpData *data)
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{
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uint x, y, i;
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byte pad = GB(4 - info->width / 8, 0, 2);
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byte *pixel_row;
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byte b;
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for (y = info->height; y > 0; y--) {
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x = 0;
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pixel_row = &data->bitmap[(y - 1) * info->width];
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while (x < info->width) {
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if (EndOfBuffer(buffer)) return false; // the file is shorter than expected
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b = ReadByte(buffer);
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for (i = 8; i > 0; i--) {
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if (x < info->width) *pixel_row++ = GB(b, i - 1, 1);
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x++;
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}
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}
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/* Padding for 32 bit align */
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SkipBytes(buffer, pad);
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}
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return true;
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}
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/**
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* Reads a 4 bpp uncompressed bitmap
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* The bitmap is converted to a 8 bpp bitmap
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*/
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static inline bool BmpRead4(BmpBuffer *buffer, BmpInfo *info, BmpData *data)
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{
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uint x, y;
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byte pad = GB(4 - info->width / 2, 0, 2);
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byte *pixel_row;
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byte b;
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for (y = info->height; y > 0; y--) {
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x = 0;
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pixel_row = &data->bitmap[(y - 1) * info->width];
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while (x < info->width) {
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if (EndOfBuffer(buffer)) return false; // the file is shorter than expected
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b = ReadByte(buffer);
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*pixel_row++ = GB(b, 4, 4);
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x++;
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if (x < info->width) {
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*pixel_row++ = GB(b, 0, 4);
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x++;
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}
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}
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/* Padding for 32 bit align */
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SkipBytes(buffer, pad);
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}
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return true;
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}
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/**
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* Reads a 4-bit RLE compressed bitmap
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* The bitmap is converted to a 8 bpp bitmap
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*/
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static inline bool BmpRead4Rle(BmpBuffer *buffer, BmpInfo *info, BmpData *data)
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{
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uint x = 0;
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uint y = info->height - 1;
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byte *pixel = &data->bitmap[y * info->width];
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while (y != 0 || x < info->width) {
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if (EndOfBuffer(buffer)) return false; // the file is shorter than expected
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byte n = ReadByte(buffer);
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byte c = ReadByte(buffer);
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if (n == 0) {
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switch (c) {
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case 0: // end of line
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x = 0;
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if (y == 0) return false;
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pixel = &data->bitmap[--y * info->width];
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break;
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case 1: // end of bitmap
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return true;
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case 2: { // delta
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if (EndOfBuffer(buffer)) return false;
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byte dx = ReadByte(buffer);
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byte dy = ReadByte(buffer);
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/* Check for over- and underflow. */
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if (x + dx >= info->width || x + dx < x || dy > y) return false;
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x += dx;
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y -= dy;
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pixel = &data->bitmap[y * info->width + x];
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break;
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}
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default: { // uncompressed
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uint i = 0;
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while (i++ < c) {
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if (EndOfBuffer(buffer) || x >= info->width) return false;
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byte b = ReadByte(buffer);
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*pixel++ = GB(b, 4, 4);
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x++;
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if (i++ < c) {
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if (x >= info->width) return false;
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*pixel++ = GB(b, 0, 4);
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x++;
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}
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}
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/* Padding for 16 bit align */
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SkipBytes(buffer, ((c + 1) / 2) % 2);
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break;
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}
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}
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} else {
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/* Apparently it is common to encounter BMPs where the count of
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* pixels to be written is higher than the remaining line width.
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* Ignore the superfluous pixels instead of reporting an error. */
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uint i = 0;
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while (x < info->width && i++ < n) {
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*pixel++ = GB(c, 4, 4);
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x++;
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if (x < info->width && i++ < n) {
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*pixel++ = GB(c, 0, 4);
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x++;
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}
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}
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}
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}
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return true;
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}
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/**
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* Reads a 8 bpp bitmap
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*/
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static inline bool BmpRead8(BmpBuffer *buffer, BmpInfo *info, BmpData *data)
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{
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uint i;
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uint y;
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byte pad = GB(4 - info->width, 0, 2);
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byte *pixel;
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for (y = info->height; y > 0; y--) {
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if (EndOfBuffer(buffer)) return false; // the file is shorter than expected
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pixel = &data->bitmap[(y - 1) * info->width];
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for (i = 0; i < info->width; i++) *pixel++ = ReadByte(buffer);
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/* Padding for 32 bit align */
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SkipBytes(buffer, pad);
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}
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return true;
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}
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/**
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* Reads a 8-bit RLE compressed bpp bitmap
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*/
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static inline bool BmpRead8Rle(BmpBuffer *buffer, BmpInfo *info, BmpData *data)
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{
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uint x = 0;
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uint y = info->height - 1;
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byte *pixel = &data->bitmap[y * info->width];
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while (y != 0 || x < info->width) {
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if (EndOfBuffer(buffer)) return false; // the file is shorter than expected
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byte n = ReadByte(buffer);
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byte c = ReadByte(buffer);
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if (n == 0) {
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switch (c) {
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case 0: // end of line
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x = 0;
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if (y == 0) return false;
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pixel = &data->bitmap[--y * info->width];
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break;
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case 1: // end of bitmap
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return true;
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case 2: { // delta
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if (EndOfBuffer(buffer)) return false;
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byte dx = ReadByte(buffer);
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byte dy = ReadByte(buffer);
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/* Check for over- and underflow. */
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if (x + dx >= info->width || x + dx < x || dy > y) return false;
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x += dx;
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y -= dy;
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pixel = &data->bitmap[y * info->width + x];
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break;
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}
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default: { // uncompressed
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for (uint i = 0; i < c; i++) {
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if (EndOfBuffer(buffer) || x >= info->width) return false;
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*pixel++ = ReadByte(buffer);
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x++;
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}
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/* Padding for 16 bit align */
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SkipBytes(buffer, c % 2);
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break;
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}
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}
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} else {
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/* Apparently it is common to encounter BMPs where the count of
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* pixels to be written is higher than the remaining line width.
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* Ignore the superfluous pixels instead of reporting an error. */
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for (uint i = 0; x < info->width && i < n; i++) {
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*pixel++ = c;
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x++;
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}
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}
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}
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return true;
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}
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/**
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* Reads a 24 bpp uncompressed bitmap
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*/
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static inline bool BmpRead24(BmpBuffer *buffer, BmpInfo *info, BmpData *data)
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{
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uint x, y;
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byte pad = GB(4 - info->width * 3, 0, 2);
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byte *pixel_row;
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for (y = info->height; y > 0; y--) {
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pixel_row = &data->bitmap[(y - 1) * info->width * 3];
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for (x = 0; x < info->width; x++) {
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if (EndOfBuffer(buffer)) return false; // the file is shorter than expected
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*(pixel_row + 2) = ReadByte(buffer); // green
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*(pixel_row + 1) = ReadByte(buffer); // blue
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*pixel_row = ReadByte(buffer); // red
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pixel_row += 3;
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}
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/* Padding for 32 bit align */
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SkipBytes(buffer, pad);
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}
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return true;
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}
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/*
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* Reads bitmap headers, and palette (if any)
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*/
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bool BmpReadHeader(BmpBuffer *buffer, BmpInfo *info, BmpData *data)
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{
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uint32 header_size;
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assert(info != NULL);
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MemSetT(info, 0);
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/* Reading BMP header */
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if (ReadWord(buffer) != 0x4D42) return false; // signature should be 'BM'
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SkipBytes(buffer, 8); // skip file size and reserved
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info->offset = ReadDword(buffer);
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/* Reading info header */
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header_size = ReadDword(buffer);
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if (header_size < 12) return false; // info header should be at least 12 bytes long
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info->os2_bmp = (header_size == 12); // OS/2 1.x or windows 2.x info header is 12 bytes long
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if (info->os2_bmp) {
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info->width = ReadWord(buffer);
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info->height = ReadWord(buffer);
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header_size -= 8;
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} else {
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info->width = ReadDword(buffer);
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info->height = ReadDword(buffer);
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header_size -= 12;
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}
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if (ReadWord(buffer) != 1) return false; // BMP can have only 1 plane
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info->bpp = ReadWord(buffer);
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if (info->bpp != 1 && info->bpp != 4 && info->bpp != 8 && info->bpp != 24) {
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/* Only 1 bpp, 4 bpp, 8bpp and 24 bpp bitmaps are supported */
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return false;
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}
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/* Reads compression method if available in info header*/
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if ((header_size -= 4) >= 4) {
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info->compression = ReadDword(buffer);
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header_size -= 4;
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}
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/* Only 4-bit and 8-bit rle compression is supported */
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if (info->compression > 2 || (info->compression > 0 && !(info->bpp == 4 || info->bpp == 8))) return false;
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if (info->bpp <= 8) {
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uint i;
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/* Reads number of colours if available in info header */
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if (header_size >= 16) {
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SkipBytes(buffer, 12); // skip image size and resolution
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info->palette_size = ReadDword(buffer); // number of colours in palette
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SkipBytes(buffer, header_size - 16); // skip the end of info header
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}
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if (info->palette_size == 0) info->palette_size = 1 << info->bpp;
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data->palette = CallocT<Colour>(info->palette_size);
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for (i = 0; i < info->palette_size; i++) {
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data->palette[i].b = ReadByte(buffer);
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data->palette[i].g = ReadByte(buffer);
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data->palette[i].r = ReadByte(buffer);
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if (!info->os2_bmp) SkipBytes(buffer, 1); // unused
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}
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}
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return buffer->real_pos <= info->offset;
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}
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/*
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* Reads the bitmap
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* 1 bpp and 4 bpp bitmaps are converted to 8 bpp bitmaps
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*/
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bool BmpReadBitmap(BmpBuffer *buffer, BmpInfo *info, BmpData *data)
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{
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assert(info != NULL && data != NULL);
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data->bitmap = CallocT<byte>(info->width * info->height * ((info->bpp == 24) ? 3 : 1));
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/* Load image */
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SetStreamOffset(buffer, info->offset);
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switch (info->compression) {
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case 0: // no compression
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switch (info->bpp) {
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case 1: return BmpRead1(buffer, info, data);
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case 4: return BmpRead4(buffer, info, data);
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case 8: return BmpRead8(buffer, info, data);
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case 24: return BmpRead24(buffer, info, data);
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default: NOT_REACHED();
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}
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case 1: return BmpRead8Rle(buffer, info, data); // 8-bit RLE compression
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case 2: return BmpRead4Rle(buffer, info, data); // 4-bit RLE compression
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default: NOT_REACHED();
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}
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}
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void BmpDestroyData(BmpData *data)
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{
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assert(data != NULL);
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free(data->palette);
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free(data->bitmap);
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}
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