diff options
Diffstat (limited to 'src/bmp.c')
-rw-r--r-- | src/bmp.c | 378 |
1 files changed, 378 insertions, 0 deletions
diff --git a/src/bmp.c b/src/bmp.c new file mode 100644 index 000000000..c2bd91270 --- /dev/null +++ b/src/bmp.c @@ -0,0 +1,378 @@ +/* $Id$ */ + +#include "stdafx.h" +#include "openttd.h" +#include "gfx.h" +#include "bmp.h" +#include "macros.h" + +void BmpInitializeBuffer(BmpBuffer *buffer, FILE *file) { + buffer->pos = -1; + buffer->file = file; + buffer->read = 0; + buffer->real_pos = ftell(file); +} + +static inline void AdvanceBuffer(BmpBuffer *buffer) +{ + buffer->read = (int)fread(buffer->data, 1, BMP_BUFFER_SIZE, buffer->file); + buffer->pos = 0; +} + +static inline bool EndOfBuffer(BmpBuffer *buffer) +{ + if (buffer->pos == buffer->read || buffer->pos < 0) AdvanceBuffer(buffer); + return buffer->pos == buffer->read; +} + +static inline byte ReadByte(BmpBuffer *buffer) +{ + if (buffer->pos == buffer->read || buffer->pos < 0) AdvanceBuffer(buffer); + buffer->real_pos++; + return buffer->data[buffer->pos++]; +} + +static inline uint16 ReadWord(BmpBuffer *buffer) +{ + uint16 var = ReadByte(buffer); + return var | (ReadByte(buffer) << 8); +} + +static inline uint32 ReadDword(BmpBuffer *buffer) +{ + uint32 var = ReadWord(buffer); + return var | (ReadWord(buffer) << 16); +} + +static inline void SkipBytes(BmpBuffer *buffer, int bytes) +{ + int i; + for (i = 0; i < bytes; i++) ReadByte(buffer); +} + +static inline void SetStreamOffset(BmpBuffer *buffer, int offset) +{ + fseek(buffer->file, offset, SEEK_SET); + buffer->pos = -1; + buffer->real_pos = offset; + AdvanceBuffer(buffer); +} + +/** + * Reads a 1 bpp uncompressed bitmap + * The bitmap is converted to a 8 bpp bitmap + */ +static inline bool BmpRead1(BmpBuffer *buffer, BmpInfo *info, BmpData *data) +{ + uint x, y, i; + byte pad = GB(4 - info->width / 8, 0, 2); + byte *pixel_row; + byte b; + for (y = info->height; y > 0; y--) { + x = 0; + pixel_row = &data->bitmap[(y - 1) * info->width]; + while (x < info->width) { + if (EndOfBuffer(buffer)) return false; // the file is shorter than expected + b = ReadByte(buffer); + for (i = 8; i > 0; i--) { + if (x < info->width) *pixel_row++ = GB(b, i - 1, 1); + x++; + } + } + /* Padding for 32 bit align */ + SkipBytes(buffer, pad); + } + return true; +} + +/** + * Reads a 4 bpp uncompressed bitmap + * The bitmap is converted to a 8 bpp bitmap + */ +static inline bool BmpRead4(BmpBuffer *buffer, BmpInfo *info, BmpData *data) +{ + uint x, y; + byte pad = GB(4 - info->width / 2, 0, 2); + byte *pixel_row; + byte b; + for (y = info->height; y > 0; y--) { + x = 0; + pixel_row = &data->bitmap[(y - 1) * info->width]; + while (x < info->width) { + if (EndOfBuffer(buffer)) return false; // the file is shorter than expected + b = ReadByte(buffer); + *pixel_row++ = GB(b, 4, 4); + x++; + if (x < info->width) { + *pixel_row++ = GB(b, 0, 4); + x++; + } + } + /* Padding for 32 bit align */ + SkipBytes(buffer, pad); + } + return true; +} + +/** + * Reads a 4-bit RLE compressed bitmap + * The bitmap is converted to a 8 bpp bitmap + */ +static inline bool BmpRead4Rle(BmpBuffer *buffer, BmpInfo *info, BmpData *data) +{ + uint i; + uint x = 0; + uint y = info->height - 1; + byte n, c, b; + byte *pixel = &data->bitmap[y * info->width]; + while (y != 0 || x < info->width) { + if (EndOfBuffer(buffer)) return false; // the file is shorter than expected + n = ReadByte(buffer); + c = ReadByte(buffer); + if (n == 0) { + switch (c) { + case 0: // end of line + x = 0; + pixel = &data->bitmap[--y * info->width]; + break; + case 1: // end of bitmap + x = info->width; + y = 0; + pixel = NULL; + break; + case 2: // delta + x += ReadByte(buffer); + i = ReadByte(buffer); + if (x >= info->width || (y == 0 && i > 0)) return false; + y -= i; + pixel = &data->bitmap[y * info->width + x]; + break; + default: // uncompressed + i = 0; + while (i++ < c) { + if (EndOfBuffer(buffer) || x >= info->width) return false; + b = ReadByte(buffer); + *pixel++ = GB(b, 4, 4); + x++; + if (x < info->width && i++ < c) { + *pixel++ = GB(b, 0, 4); + x++; + } + } + /* Padding for 16 bit align */ + SkipBytes(buffer, ((c + 1) / 2) % 2); + break; + } + } else { + i = 0; + while (i++ < n) { + if (EndOfBuffer(buffer) || x >= info->width) return false; + *pixel++ = GB(c, 4, 4); + x++; + if (x < info->width && i++ < n) { + *pixel++ = GB(c, 0, 4); + x++; + } + } + } + } + return true; +} + +/** + * Reads a 8 bpp bitmap + */ +static inline bool BmpRead8(BmpBuffer *buffer, BmpInfo *info, BmpData *data) +{ + uint i; + uint y; + byte pad = GB(4 - info->width, 0, 2); + byte *pixel; + for (y = info->height; y > 0; y--) { + if (EndOfBuffer(buffer)) return false; // the file is shorter than expected + pixel = &data->bitmap[(y - 1) * info->width]; + for (i = 0; i < info->width; i++) *pixel++ = ReadByte(buffer); + /* Padding for 32 bit align */ + SkipBytes(buffer, pad); + } + return true; +} + +/** + * Reads a 8-bit RLE compressed bpp bitmap + */ +static inline bool BmpRead8Rle(BmpBuffer *buffer, BmpInfo *info, BmpData *data) +{ + uint i; + uint x = 0; + uint y = info->height - 1; + byte n, c; + byte *pixel = &data->bitmap[y * info->width]; + while (y != 0 || x < info->width) { + if (EndOfBuffer(buffer)) return false; // the file is shorter than expected + n = ReadByte(buffer); + c = ReadByte(buffer); + if (n == 0) { + switch (c) { + case 0: // end of line + x = 0; + pixel = &data->bitmap[--y * info->width]; + break; + case 1: // end of bitmap + x = info->width; + y = 0; + pixel = NULL; + break; + case 2: // delta + x += ReadByte(buffer); + i = ReadByte(buffer); + if (x >= info->width || (y == 0 && i > 0)) return false; + y -= i; + pixel = &data->bitmap[y * info->width + x]; + break; + default: // uncompressed + if ((x += c) > info->width) return false; + for (i = 0; i < c; i++) *pixel++ = ReadByte(buffer); + /* Padding for 16 bit align */ + SkipBytes(buffer, c % 2); + break; + } + } else { + for (i = 0; i < n; i++) { + if (x >= info->width) return false; + *pixel++ = c; + x++; + } + } + } + return true; +} + +/** + * Reads a 24 bpp uncompressed bitmap + */ +static inline bool BmpRead24(BmpBuffer *buffer, BmpInfo *info, BmpData *data) +{ + uint x, y; + byte pad = GB(4 - info->width * 3, 0, 2); + byte *pixel_row; + for (y = info->height; y > 0; y--) { + pixel_row = &data->bitmap[(y - 1) * info->width * 3]; + for (x = 0; x < info->width; x++) { + if (EndOfBuffer(buffer)) return false; // the file is shorter than expected + *(pixel_row + 2) = ReadByte(buffer); // green + *(pixel_row + 1) = ReadByte(buffer); // blue + *pixel_row = ReadByte(buffer); // red + pixel_row += 3; + } + /* Padding for 32 bit align */ + SkipBytes(buffer, pad); + } + return true; +} + +/* + * Reads bitmap headers, and palette (if any) + */ +bool BmpReadHeader(BmpBuffer *buffer, BmpInfo *info, BmpData *data) +{ + uint32 header_size; + assert(info != NULL); + + /* Reading BMP header */ + if (ReadWord(buffer) != 0x4D42) return false; // signature should be 'BM' + SkipBytes(buffer, 8); // skip file size and reserved + info->offset = ReadDword(buffer); + + /* Reading info header */ + header_size = ReadDword(buffer); + if (header_size < 12) return false; // info header should be at least 12 bytes long + + info->os2_bmp = (header_size == 12); // OS/2 1.x or windows 2.x info header is 12 bytes long + + if (info->os2_bmp) { + info->width = ReadWord(buffer); + info->height = ReadWord(buffer); + header_size -= 8; + } else { + info->width = ReadDword(buffer); + info->height = ReadDword(buffer); + header_size -= 12; + } + + if (ReadWord(buffer) != 1) return false; // BMP can have only 1 plane + + info->bpp = ReadWord(buffer); + if (info->bpp != 1 && info->bpp != 4 && info->bpp != 8 && info->bpp != 24) { + /* Only 1 bpp, 4 bpp, 8bpp and 24 bpp bitmaps are supported */ + return false; + } + + /* Reads compression method if available in info header*/ + if ((header_size -= 4) >= 4) { + info->compression = ReadDword(buffer); + header_size -= 4; + } + + /* Only 4-bit and 8-bit rle compression is supported */ + if (info->compression > 2 || (info->compression > 0 && !(info->bpp == 4 || info->bpp == 8))) return false; + + if (info->bpp <= 8) { + uint i; + + /* Reads number of colors if available in info header */ + if (header_size >= 16) { + SkipBytes(buffer, 12); // skip image size and resolution + info->palette_size = ReadDword(buffer); // number of colors in palette + SkipBytes(buffer, header_size - 16); // skip the end of info header + } + if (info->palette_size == 0) info->palette_size = 1 << info->bpp; + + data->palette = calloc(info->palette_size, sizeof(*(data->palette))); + if (data->palette == NULL) return false; + + for (i = 0; i < info->palette_size; i++) { + data->palette[i].b = ReadByte(buffer); + data->palette[i].g = ReadByte(buffer); + data->palette[i].r = ReadByte(buffer); + if (!info->os2_bmp) SkipBytes(buffer, 1); // unused + } + } + + return buffer->real_pos <= info->offset; +} + +/* + * Reads the bitmap + * 1 bpp and 4 bpp bitmaps are converted to 8 bpp bitmaps + */ +bool BmpReadBitmap(BmpBuffer *buffer, BmpInfo *info, BmpData *data) +{ + assert(info != NULL && data != NULL); + + data->bitmap = calloc(info->width * info->height, ((info->bpp == 24) ? 3 : 1) * sizeof(byte)); + if (data->bitmap == NULL) return false; + + /* Load image */ + SetStreamOffset(buffer, info->offset); + switch (info->compression) { + case 0: // no compression + switch (info->bpp) { + case 1: return BmpRead1(buffer, info, data); + case 4: return BmpRead4(buffer, info, data); + case 8: return BmpRead8(buffer, info, data); + case 24: return BmpRead24(buffer, info, data); + default: NOT_REACHED(); return false; + } + case 1: return BmpRead8Rle(buffer, info, data); // 8-bit RLE compression + case 2: return BmpRead4Rle(buffer, info, data); // 4-bit RLE compression + default: NOT_REACHED(); return false; + } +} + +void BmpDestroyData(BmpData *data) +{ + assert(data != NULL); + free(data->palette); + free(data->bitmap); +} |