// license:BSD-3-Clause // copyright-holders:Vas Crabb /*************************************************************************** msdib.h Microsoft Device-Independent Bitmap file loading. ***************************************************************************/ #include "msdib.h" #include "eminline.h" #include #include #include #define LOG_GENERAL (1U << 0) #define LOG_DIB (1U << 1) //#define VERBOSE (LOG_GENERAL | LOG_DIB) #define LOG_OUTPUT_FUNC osd_printf_verbose #ifndef VERBOSE #define VERBOSE 0 #endif #define LOGMASKED(mask, ...) do { if (VERBOSE & (mask)) (LOG_OUTPUT_FUNC)(__VA_ARGS__); } while (false) #define LOG(...) LOGMASKED(LOG_GENERAL, __VA_ARGS__) namespace util { namespace { // DIB compression schemes enum : std::uint32_t { DIB_COMP_NONE = 0, DIB_COMP_RLE8 = 1, DIB_COMP_RLE4 = 2, DIB_COMP_BITFIELDS = 3 }; // file header doesn't use natural alignment using bitmap_file_header = std::uint8_t [14]; // old-style DIB header struct bitmap_core_header { std::uint32_t size; // size of the header (12, 16 or 64) std::int16_t width; // width of bitmap in pixels std::int16_t height; // height of the image in pixels std::uint16_t planes; // number of colour planes (must be 1) std::uint16_t bpp; // bits per pixel }; // new-style DIB header struct bitmap_info_header { std::uint32_t size; // size of the header std::int32_t width; // width of bitmap in pixels std::int32_t height; // height of bitmap in pixels std::uint16_t planes; // number of colour planes (must be 1) std::uint16_t bpp; // bits per pixel std::uint32_t comp; // compression method std::uint32_t rawsize; // size of bitmap data after decompression or 0 if uncompressed std::int32_t hres; // horizontal resolution in pixels/metre std::int32_t vres; // horizontal resolution in pixels/metre std::uint32_t colors; // number of colours or 0 for 1 << bpp std::uint32_t important; // number of important colours or 0 if all important std::uint32_t red; // red field mask - must be contiguous std::uint32_t green; // green field mask - must be contiguous std::uint32_t blue; // blue field mask - must be contiguous std::uint32_t alpha; // alpha field mask - must be contiguous }; union bitmap_headers { bitmap_core_header core; bitmap_info_header info; }; bool dib_parse_mask(uint32_t mask, unsigned &shift, unsigned &bits) { shift = count_leading_zeros(mask); mask <<= shift; bits = count_leading_ones(mask); mask <<= shift; shift = 32 - shift - bits; return !mask; } void dib_truncate_channel(unsigned &shift, unsigned &bits) { if (8U < bits) { unsigned const excess(bits - 8); shift += excess; bits -= excess; } } uint8_t dib_splat_sample(uint8_t val, unsigned bits) { assert(8U >= bits); for (val <<= (8U - bits); bits && (8U > bits); bits <<= 1) val |= val >> bits; return val; } msdib_error dib_read_file_header(core_file &fp, std::uint32_t &filelen) { // the bitmap file header doesn't use natural alignment bitmap_file_header file_header; if (fp.read(file_header, sizeof(file_header)) != sizeof(file_header)) { LOG("Error reading DIB file header\n"); return msdib_error::FILE_TRUNCATED; } // only support Windows bitmaps for now if ((0x42 != file_header[0]) || (0x4d != file_header[1])) return msdib_error::BAD_SIGNATURE; // do a very basic check on the file length std::uint32_t const file_length( (std::uint32_t(file_header[2]) << 0) | (std::uint32_t(file_header[3]) << 8) | (std::uint32_t(file_header[4]) << 16) | (std::uint32_t(file_header[5]) << 24)); if ((sizeof(file_header) + sizeof(bitmap_core_header)) > file_length) return msdib_error::FILE_CORRUPT; // check that the offset to the pixel data looks half sane std::uint32_t const pixel_offset( (std::uint32_t(file_header[10]) << 0) | (std::uint32_t(file_header[11]) << 8) | (std::uint32_t(file_header[12]) << 16) | (std::uint32_t(file_header[13]) << 24)); if (((sizeof(file_header) + sizeof(bitmap_core_header)) > pixel_offset) || (file_length < pixel_offset)) return msdib_error::FILE_CORRUPT; // looks OK enough filelen = file_length; return msdib_error::NONE; } msdib_error dib_read_bitmap_header( core_file &fp, bitmap_headers &header, unsigned &palette_bytes, bool &indexed, std::size_t &palette_entries, std::size_t &palette_size, std::size_t &row_bytes, std::uint32_t length) { // check that these things haven't been padded somehow static_assert(sizeof(bitmap_core_header) == 12U, "compiler has applied padding to bitmap_core_header"); static_assert(sizeof(bitmap_info_header) == 56U, "compiler has applied padding to bitmap_info_header"); // ensure the header fits in the space for the image data assert(&header.core.size == &header.info.size); if (sizeof(header.core) > length) return msdib_error::FILE_TRUNCATED; std::memset(&header, 0, sizeof(header)); if (fp.read(&header.core.size, sizeof(header.core.size)) != sizeof(header.core.size)) { LOG("Error reading DIB header size (length %u)\n", length); return msdib_error::FILE_TRUNCATED; } header.core.size = little_endianize_int32(header.core.size); if (length < header.core.size) { LOG("DIB image data (%u bytes) is too small for DIB header (%u bytes)\n", length, header.core.size); return msdib_error::FILE_CORRUPT; } // identify and read the header - convert OS/2 headers to Windows 3 format palette_bytes = 4U; switch (header.core.size) { case 16U: case 64U: // extended OS/2 bitmap header with support for compression LOG( "DIB image data (%u bytes) uses unsupported OS/2 DIB header (size %u)\n", length, header.core.size); return msdib_error::UNSUPPORTED_FORMAT; case 12U: // introduced in OS/2 and Windows 2.0 { palette_bytes = 3U; std::uint32_t const header_read(std::min(header.core.size, sizeof(header.core)) - sizeof(header.core.size)); if (fp.read(&header.core.width, header_read) != header_read) { LOG("Error reading DIB core header from image data (%u bytes)\n", length); return msdib_error::FILE_TRUNCATED; } fp.seek(header.core.size - sizeof(header.core.size) - header_read, SEEK_CUR); header.core.width = little_endianize_int16(header.core.width); header.core.height = little_endianize_int16(header.core.height); header.core.planes = little_endianize_int16(header.core.planes); header.core.bpp = little_endianize_int16(header.core.bpp); LOGMASKED( LOG_DIB, "Read DIB core header from image data : %d*%d, %u planes, %u bpp\n", header.core.width, header.core.height, header.core.planes, header.core.bpp); // this works because the core header only aliases the width/height of the info header header.info.bpp = header.core.bpp; header.info.planes = header.core.planes; header.info.height = header.core.height; header.info.width = header.core.width; header.info.size = 40U; } break; default: // the next version will be longer if (124U >= header.core.size) { LOG( "DIB image data (%u bytes) uses unsupported DIB header format (size %u)\n", length, header.core.size); return msdib_error::UNSUPPORTED_FORMAT; } // fall through case 40U: case 52U: case 56U: case 108U: case 124U: // the Windows 3 bitmap header with optional extensions { palette_bytes = 4U; std::uint32_t const header_read(std::min(header.info.size, sizeof(header.info)) - sizeof(header.info.size)); if (fp.read(&header.info.width, header_read) != header_read) { LOG("Error reading DIB info header from image data (%u bytes)\n", length); return msdib_error::FILE_TRUNCATED; } fp.seek(header.info.size - sizeof(header.info.size) - header_read, SEEK_CUR); header.info.width = little_endianize_int32(header.info.width); header.info.height = little_endianize_int32(header.info.height); header.info.planes = little_endianize_int16(header.info.planes); header.info.bpp = little_endianize_int16(header.info.bpp); header.info.comp = little_endianize_int32(header.info.comp); header.info.rawsize = little_endianize_int32(header.info.rawsize); header.info.hres = little_endianize_int32(header.info.hres); header.info.vres = little_endianize_int32(header.info.vres); header.info.colors = little_endianize_int32(header.info.colors); header.info.important = little_endianize_int32(header.info.important); header.info.red = little_endianize_int32(header.info.red); header.info.green = little_endianize_int32(header.info.green); header.info.blue = little_endianize_int32(header.info.blue); header.info.alpha = little_endianize_int32(header.info.alpha); LOGMASKED( LOG_DIB, "Read DIB info header from image data: %d*%d (%d*%d ppm), %u planes, %u bpp %u/%s%u colors\n", header.info.width, header.info.height, header.info.hres, header.info.vres, header.info.planes, header.info.bpp, header.info.important, header.info.colors ? "" : "2^", header.info.colors ? header.info.colors : header.info.bpp); } break; } // check for unsupported planes/bit depth if ((1U != header.info.planes) || !header.info.bpp || (32U < header.info.bpp) || ((8U < header.info.bpp) ? (header.info.bpp % 8) : (8 % header.info.bpp))) { LOG("DIB image data uses unsupported planes/bits per pixel %u*%u\n", header.info.planes, header.info.bpp); return msdib_error::UNSUPPORTED_FORMAT; } // check dimensions if ((0 >= header.info.width) || (0 == header.info.height)) { LOG("DIB image data has invalid dimensions %u*%u\n", header.info.width, header.info.height); return msdib_error::FILE_CORRUPT; } // ensure compression scheme is supported bool no_palette(false); indexed = true; switch (header.info.comp) { case DIB_COMP_NONE: // uncompressed - direct colour with implied bitfields if more than eight bits/pixel indexed = 8U >= header.info.bpp; if (indexed) { if ((1U << header.info.bpp) < header.info.colors) { osd_printf_verbose( "DIB image data has oversized palette with %u entries for %u bits per pixel\n", header.info.colors, header.info.bpp); } } if (!indexed) { no_palette = true; switch(header.info.bpp) { case 16U: header.info.red = 0x00007c00; header.info.green = 0x000003e0; header.info.blue = 0x0000001f; header.info.alpha = 0x00000000; break; case 24U: case 32U: header.info.red = 0x00ff0000; header.info.green = 0x0000ff00; header.info.blue = 0x000000ff; header.info.alpha = 0x00000000; break; } } break; case DIB_COMP_BITFIELDS: // uncompressed direct colour with explicitly-specified bitfields indexed = false; if (offsetof(bitmap_info_header, alpha) > header.info.size) { osd_printf_verbose( "DIB image data specifies bit masks but is too small (size %u)\n", header.info.size); return msdib_error::FILE_CORRUPT; } break; default: LOG("DIB image data uses unsupported compression scheme %u\n", header.info.comp); return msdib_error::UNSUPPORTED_FORMAT; } // we can now calculate the size of the palette and row data palette_entries = indexed ? ((1U == header.info.bpp) ? 2U : header.info.colors ? header.info.colors : (1U << header.info.bpp)) : (no_palette ? 0U : header.info.colors); palette_size = palette_bytes * palette_entries; row_bytes = ((31 + (header.info.width * header.info.bpp)) >> 5) << 2; // header looks OK return msdib_error::NONE; } } // anonymous namespace msdib_error msdib_verify_header(core_file &fp) { msdib_error err; // file header std::uint32_t file_length; err = dib_read_file_header(fp, file_length); if (msdib_error::NONE != err) return err; // bitmap header bitmap_headers header; unsigned palette_bytes; bool indexed; std::size_t palette_entries, palette_size, row_bytes; err = dib_read_bitmap_header( fp, header, palette_bytes, indexed, palette_entries, palette_size, row_bytes, file_length - sizeof(bitmap_file_header)); if (msdib_error::NONE != err) return err; // check length std::size_t const required_size( sizeof(bitmap_file_header) + header.info.size + palette_size + (row_bytes * std::abs(header.info.height))); if (required_size > file_length) return msdib_error::FILE_TRUNCATED; // good chance this file is supported return msdib_error::NONE; } msdib_error msdib_read_bitmap(core_file &fp, bitmap_argb32 &bitmap) { std::uint32_t file_length; msdib_error const headerr(dib_read_file_header(fp, file_length)); if (msdib_error::NONE != headerr) return headerr; return msdib_read_bitmap_data(fp, bitmap, file_length - sizeof(bitmap_file_header), 0U); } msdib_error msdib_read_bitmap_data(core_file &fp, bitmap_argb32 &bitmap, std::uint32_t length, std::uint32_t dirheight) { // read the bitmap header bitmap_headers header; unsigned palette_bytes; bool indexed; std::size_t palette_entries, palette_size, row_bytes; msdib_error const head_error(dib_read_bitmap_header(fp, header, palette_bytes, indexed, palette_entries, palette_size, row_bytes, length)); if (msdib_error::NONE != head_error) return head_error; // check dimensions bool const top_down(0 > header.info.height); if (top_down) header.info.height = -header.info.height; bool have_and_mask((2 * dirheight) == header.info.height); if (!have_and_mask && (0 < dirheight) && (dirheight != header.info.height)) { osd_printf_verbose( "DIB image data height %d doesn't match directory height %u with or without AND mask\n", header.info.height, dirheight); return msdib_error::UNSUPPORTED_FORMAT; } if (have_and_mask) header.info.height >>= 1; // we can now calculate the size of the image data std::size_t const mask_row_bytes(((31 + header.info.width) >> 5) << 2); std::size_t const required_size( header.info.size + palette_size + ((row_bytes + (have_and_mask ? mask_row_bytes : 0U)) * header.info.height)); if (required_size > length) { LOG("DIB image data (%u bytes) smaller than calculated DIB data size (%u bytes)\n", length, required_size); return msdib_error::FILE_TRUNCATED; } // load the palette for indexed colour formats or the shifts for direct colour formats unsigned red_shift(0), green_shift(0), blue_shift(0), alpha_shift(0); unsigned red_bits(0), green_bits(0), blue_bits(0), alpha_bits(0); std::unique_ptr palette; if (indexed) { // read palette and convert std::unique_ptr palette_data; try { palette_data.reset(new std::uint8_t [palette_size]); } catch (std::bad_alloc const &) { return msdib_error::OUT_OF_MEMORY; } if (fp.read(palette_data.get(), palette_size) != palette_size) { LOG("Error reading palette from DIB image data (%u bytes)\n", length); return msdib_error::FILE_TRUNCATED; } std::size_t const palette_usable(std::min(palette_entries, std::size_t(1) << header.info.bpp)); try { palette.reset(new rgb_t [palette_usable]); } catch (std::bad_alloc const &) { return msdib_error::OUT_OF_MEMORY; } std::uint8_t const *ptr(palette_data.get()); for (std::size_t i = 0; palette_usable > i; ++i, ptr += palette_bytes) palette[i] = rgb_t(ptr[2], ptr[1], ptr[0]); } else { // skip over the palette if necessary if (palette_entries) fp.seek(palette_bytes * palette_entries, SEEK_CUR); // convert masks to shifts bool const masks_contiguous( dib_parse_mask(header.info.red, red_shift, red_bits) && dib_parse_mask(header.info.green, green_shift, green_bits) && dib_parse_mask(header.info.blue, blue_shift, blue_bits) && dib_parse_mask(header.info.alpha, alpha_shift, alpha_bits)); if (!masks_contiguous) { osd_printf_verbose( "DIB image data specifies non-contiguous channel masks 0x%x | 0x%x | 0x%x | 0x%x\n", header.info.red, header.info.green, header.info.blue, header.info.alpha); } if ((32U != header.info.bpp) && ((header.info.red | header.info.green | header.info.blue | header.info.alpha) >> header.info.bpp)) { LOG( "DIB image data specifies channel masks 0x%x | 0x%x | 0x%x | 0x%x that exceed %u bits per pixel\n", header.info.red, header.info.green, header.info.blue, header.info.alpha, header.info.bpp); return msdib_error::FILE_CORRUPT; } LOGMASKED( LOG_DIB, "DIB image data using channels: R((x >> %2$u) & 0x%3$0*1$x) G((x >> %4$u) & 0x%5$0*1$x) B((x >> %6$u) & 0x%7$0*1$x) A((x >> %8$u) & 0x%9$0*1$x)\n", (header.info.bpp + 3) >> 2, red_shift, (std::uint32_t(1) << red_bits) - 1, green_shift, (std::uint32_t(1) << green_bits) - 1, blue_shift, (std::uint32_t(1) << blue_bits) - 1, alpha_shift, (std::uint32_t(1) << alpha_bits) - 1); // the MAME bitmap only supports 8 bits/sample maximum dib_truncate_channel(red_shift, red_bits); dib_truncate_channel(green_shift, green_bits); dib_truncate_channel(blue_shift, blue_bits); dib_truncate_channel(alpha_shift, alpha_bits); } // allocate the bitmap and process row data std::unique_ptr row_data; try {row_data.reset(new std::uint8_t [row_bytes]); } catch (std::bad_alloc const &) { return msdib_error::OUT_OF_MEMORY; } bitmap.allocate(header.info.width, header.info.height); int const y_inc(top_down ? 1 : -1); for (std::int32_t i = 0, y = top_down ? 0 : (header.info.height - 1); header.info.height > i; ++i, y += y_inc) { if (fp.read(row_data.get(), row_bytes) != row_bytes) { LOG("Error reading DIB row %d data from image data\n", i); return msdib_error::FILE_TRUNCATED; } std::uint8_t *src(row_data.get()); std::uint32_t *dest(&bitmap.pix(y)); unsigned shift(0U); for (std::int32_t x = 0; header.info.width > x; ++x, ++dest) { // extract or compose a pixel std::uint32_t pix(0U); if (8U >= header.info.bpp) { assert(8U > shift); pix = *src >> (8U - header.info.bpp); *src <<= header.info.bpp; shift += header.info.bpp; if (8U <= shift) { shift = 0U; ++src; } } else for (shift = 0; header.info.bpp > shift; shift += 8U, ++src) { pix |= std::uint32_t(*src) << shift; } // convert to RGB if (indexed) { if (palette_entries > pix) { *dest = palette[pix]; } else { *dest = rgb_t::transparent(); osd_printf_verbose( "DIB image data has out-of-range color %u at (%d, %d) with %u palette entries\n", pix, x, y, palette_entries); } } else { std::uint8_t r(dib_splat_sample((pix >> red_shift) & ((std::uint32_t(1) << red_bits) - 1), red_bits)); std::uint8_t g(dib_splat_sample((pix >> green_shift) & ((std::uint32_t(1) << green_bits) - 1), green_bits)); std::uint8_t b(dib_splat_sample((pix >> blue_shift) & ((std::uint32_t(1) << blue_bits) - 1), blue_bits)); std::uint8_t a(dib_splat_sample((pix >> alpha_shift) & ((std::uint32_t(1) << alpha_bits) - 1), alpha_bits)); *dest = rgb_t(alpha_bits ? a : 255, r, g, b); } } } // process the AND mask if present if (have_and_mask) { for (std::int32_t i = 0, y = top_down ? 0 : (header.info.height - 1); header.info.height > i; ++i, y += y_inc) { if (fp.read(row_data.get(), mask_row_bytes) != mask_row_bytes) { LOG("Error reading DIB mask row %d data from image data\n", i); return msdib_error::FILE_TRUNCATED; } std::uint8_t *src(row_data.get()); std::uint32_t *dest(&bitmap.pix(y)); unsigned shift(0U); for (std::int32_t x = 0; header.info.width > x; ++x, ++dest) { assert(8U > shift); rgb_t pix(*dest); *dest = pix.set_a(BIT(*src, 7U - shift) ? 0U : pix.a()); if (8U <= ++shift) { shift = 0U; ++src; } } } } // we're done! return msdib_error::NONE; } } // namespace util