diff options
Diffstat (limited to 'grub-core/video/readers/png.c')
| -rw-r--r-- | grub-core/video/readers/png.c | 1166 |
1 files changed, 1166 insertions, 0 deletions
diff --git a/grub-core/video/readers/png.c b/grub-core/video/readers/png.c new file mode 100644 index 0000000..0157ff7 --- /dev/null +++ b/grub-core/video/readers/png.c @@ -0,0 +1,1166 @@ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2008,2009 Free Software Foundation, Inc. + * + * GRUB 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, either version 3 of the License, or + * (at your option) any later version. + * + * GRUB 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. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GRUB. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <grub/bitmap.h> +#include <grub/types.h> +#include <grub/normal.h> +#include <grub/dl.h> +#include <grub/mm.h> +#include <grub/misc.h> +#include <grub/bufio.h> +#include <grub/safemath.h> + +GRUB_MOD_LICENSE ("GPLv3+"); + +/* Uncomment following define to enable PNG debug. */ +//#define PNG_DEBUG + +enum + { + PNG_COLOR_TYPE_GRAY = 0, + PNG_COLOR_MASK_PALETTE = 1, + PNG_COLOR_MASK_COLOR = 2, + PNG_COLOR_MASK_ALPHA = 4, + PNG_COLOR_TYPE_PALETTE = (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE), + }; + +#define PNG_COMPRESSION_BASE 0 + +#define PNG_INTERLACE_NONE 0 +#define PNG_INTERLACE_ADAM7 1 + +#define PNG_FILTER_TYPE_BASE 0 + +#define PNG_FILTER_VALUE_NONE 0 +#define PNG_FILTER_VALUE_SUB 1 +#define PNG_FILTER_VALUE_UP 2 +#define PNG_FILTER_VALUE_AVG 3 +#define PNG_FILTER_VALUE_PAETH 4 +#define PNG_FILTER_VALUE_LAST 5 + +enum + { + PNG_CHUNK_IHDR = 0x49484452, + PNG_CHUNK_IDAT = 0x49444154, + PNG_CHUNK_IEND = 0x49454e44, + PNG_CHUNK_PLTE = 0x504c5445 + }; + +#define Z_DEFLATED 8 +#define Z_FLAG_DICT 32 + +#define INFLATE_STORED 0 +#define INFLATE_FIXED 1 +#define INFLATE_DYNAMIC 2 + +#define WSIZE 0x8000 + +#define DEFLATE_HCLEN_BASE 4 +#define DEFLATE_HCLEN_MAX 19 +#define DEFLATE_HLIT_BASE 257 +#define DEFLATE_HLIT_MAX 288 +#define DEFLATE_HDIST_BASE 1 +#define DEFLATE_HDIST_MAX 30 + +#define DEFLATE_HUFF_LEN 16 + +#ifdef PNG_DEBUG +static grub_command_t cmd; +#endif + +struct huff_table +{ + int *values, *maxval, *offset; + int num_values, max_length; +}; + +struct grub_png_data +{ + grub_file_t file; + struct grub_video_bitmap **bitmap; + + int bit_count, bit_save; + + grub_uint32_t next_offset; + + unsigned image_width, image_height; + int bpp, is_16bit; + int raw_bytes, is_gray, is_alpha, is_palette; + int row_bytes, color_bits; + grub_uint8_t *image_data; + + int inside_idat, idat_remain; + + int code_values[DEFLATE_HLIT_MAX]; + int code_maxval[DEFLATE_HUFF_LEN]; + int code_offset[DEFLATE_HUFF_LEN]; + + int dist_values[DEFLATE_HDIST_MAX]; + int dist_maxval[DEFLATE_HUFF_LEN]; + int dist_offset[DEFLATE_HUFF_LEN]; + + grub_uint8_t palette[256][3]; + + struct huff_table code_table; + struct huff_table dist_table; + + grub_uint8_t slide[WSIZE]; + int wp; + + grub_uint8_t *cur_rgb; + + int cur_column, cur_filter, first_line; +}; + +static grub_uint32_t +grub_png_get_dword (struct grub_png_data *data) +{ + grub_uint32_t r; + + r = 0; + grub_file_read (data->file, &r, sizeof (grub_uint32_t)); + + return grub_be_to_cpu32 (r); +} + +static grub_uint8_t +grub_png_get_byte (struct grub_png_data *data) +{ + grub_uint8_t r; + + if ((data->inside_idat) && (data->idat_remain == 0)) + { + grub_uint32_t len, type; + + do + { + /* Skip crc checksum. */ + grub_png_get_dword (data); + + if (data->file->offset != data->next_offset) + { + grub_error (GRUB_ERR_BAD_FILE_TYPE, + "png: chunk size error"); + return 0; + } + + len = grub_png_get_dword (data); + type = grub_png_get_dword (data); + if (type != PNG_CHUNK_IDAT) + { + grub_error (GRUB_ERR_BAD_FILE_TYPE, + "png: unexpected end of data"); + return 0; + } + + data->next_offset = data->file->offset + len + 4; + } + while (len == 0); + data->idat_remain = len; + } + + r = 0; + grub_file_read (data->file, &r, 1); + + if (data->inside_idat) + data->idat_remain--; + + return r; +} + +static int +grub_png_get_bits (struct grub_png_data *data, int num) +{ + int code, shift; + + if (data->bit_count == 0) + { + data->bit_save = grub_png_get_byte (data); + data->bit_count = 8; + } + + code = 0; + shift = 0; + while (grub_errno == 0) + { + int n; + + n = data->bit_count; + if (n > num) + n = num; + + code += (int) (data->bit_save & ((1 << n) - 1)) << shift; + num -= n; + if (!num) + { + data->bit_count -= n; + data->bit_save >>= n; + break; + } + + shift += n; + + data->bit_save = grub_png_get_byte (data); + data->bit_count = 8; + } + + return code; +} + +static grub_err_t +grub_png_decode_image_palette (struct grub_png_data *data, + unsigned len) +{ + unsigned i = 0, j; + + if (len == 0) + return GRUB_ERR_NONE; + + for (i = 0; 3 * i < len && i < 256; i++) + for (j = 0; j < 3; j++) + data->palette[i][j] = grub_png_get_byte (data); + for (i *= 3; i < len; i++) + grub_png_get_byte (data); + + grub_png_get_dword (data); + + return GRUB_ERR_NONE; +} + +static grub_err_t +grub_png_decode_image_header (struct grub_png_data *data) +{ + int color_type; + int color_bits; + enum grub_video_blit_format blt; + + data->image_width = grub_png_get_dword (data); + data->image_height = grub_png_get_dword (data); + + if ((!data->image_height) || (!data->image_width)) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, "png: invalid image size"); + + color_bits = grub_png_get_byte (data); + data->is_16bit = (color_bits == 16); + + color_type = grub_png_get_byte (data); + + /* According to PNG spec, no other types are valid. */ + if ((color_type & ~(PNG_COLOR_MASK_ALPHA | PNG_COLOR_MASK_COLOR)) + && (color_type != PNG_COLOR_TYPE_PALETTE)) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, + "png: color type not supported"); + if (color_type == PNG_COLOR_TYPE_PALETTE) + data->is_palette = 1; + if (data->is_16bit && data->is_palette) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, + "png: color type not supported"); + if (color_type & PNG_COLOR_MASK_ALPHA) + blt = GRUB_VIDEO_BLIT_FORMAT_RGBA_8888; + else + blt = GRUB_VIDEO_BLIT_FORMAT_RGB_888; + if (data->is_palette) + data->bpp = 1; + else if (color_type & PNG_COLOR_MASK_COLOR) + data->bpp = 3; + else + { + data->is_gray = 1; + data->bpp = 1; + } + + if ((color_bits != 8) && (color_bits != 16) + && (color_bits != 4 + || !(data->is_gray || data->is_palette))) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, + "png: bit depth must be 8 or 16"); + + if (color_type & PNG_COLOR_MASK_ALPHA) + data->bpp++; + + if (grub_video_bitmap_create (data->bitmap, data->image_width, + data->image_height, + blt)) + return grub_errno; + + if (data->is_16bit) + data->bpp <<= 1; + + data->color_bits = color_bits; + + if (grub_mul (data->image_width, data->bpp, &data->row_bytes)) + return grub_error (GRUB_ERR_OUT_OF_RANGE, N_("overflow is detected")); + + if (data->color_bits <= 4) + { + if (grub_mul (data->image_width, data->color_bits + 7, &data->row_bytes)) + return grub_error (GRUB_ERR_OUT_OF_RANGE, N_("overflow is detected")); + + data->row_bytes >>= 3; + } + +#ifndef GRUB_CPU_WORDS_BIGENDIAN + if (data->is_16bit || data->is_gray || data->is_palette) +#endif + { + data->image_data = grub_calloc (data->image_height, data->row_bytes); + if (grub_errno) + return grub_errno; + + data->cur_rgb = data->image_data; + } +#ifndef GRUB_CPU_WORDS_BIGENDIAN + else + { + data->image_data = 0; + data->cur_rgb = (*data->bitmap)->data; + } +#endif + + data->raw_bytes = data->image_height * (data->row_bytes + 1); + + data->cur_column = 0; + data->first_line = 1; + + if (grub_png_get_byte (data) != PNG_COMPRESSION_BASE) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, + "png: compression method not supported"); + + if (grub_png_get_byte (data) != PNG_FILTER_TYPE_BASE) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, + "png: filter method not supported"); + + if (grub_png_get_byte (data) != PNG_INTERLACE_NONE) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, + "png: interlace method not supported"); + + /* Skip crc checksum. */ + grub_png_get_dword (data); + + return grub_errno; +} + +/* Order of the bit length code lengths. */ +static const grub_uint8_t bitorder[] = { + 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 +}; + +/* Copy lengths for literal codes 257..285. */ +static const int cplens[] = { + 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, + 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0 +}; + +/* Extra bits for literal codes 257..285. */ +static const grub_uint8_t cplext[] = { + 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, + 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99 +}; /* 99==invalid */ + +/* Copy offsets for distance codes 0..29. */ +static const int cpdist[] = { + 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, + 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, + 8193, 12289, 16385, 24577 +}; + +/* Extra bits for distance codes. */ +static const grub_uint8_t cpdext[] = { + 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, + 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, + 12, 12, 13, 13 +}; + +static void +grub_png_init_huff_table (struct huff_table *ht, int cur_maxlen, + int *cur_values, int *cur_maxval, int *cur_offset) +{ + ht->values = cur_values; + ht->maxval = cur_maxval; + ht->offset = cur_offset; + ht->num_values = 0; + ht->max_length = cur_maxlen; + grub_memset (cur_maxval, 0, sizeof (int) * cur_maxlen); +} + +static void +grub_png_insert_huff_item (struct huff_table *ht, int code, int len) +{ + int i, n; + + if (len == 0) + return; + + if (len > ht->max_length) + { + grub_error (GRUB_ERR_BAD_FILE_TYPE, "png: invalid code length"); + return; + } + + n = 0; + for (i = len; i < ht->max_length; i++) + n += ht->maxval[i]; + + for (i = 0; i < n; i++) + ht->values[ht->num_values - i] = ht->values[ht->num_values - i - 1]; + + ht->values[ht->num_values - n] = code; + ht->num_values++; + ht->maxval[len - 1]++; +} + +static void +grub_png_build_huff_table (struct huff_table *ht) +{ + int base, ofs, i; + + base = 0; + ofs = 0; + for (i = 0; i < ht->max_length; i++) + { + base += ht->maxval[i]; + ofs += ht->maxval[i]; + + ht->maxval[i] = base; + ht->offset[i] = ofs - base; + + base <<= 1; + } +} + +static int +grub_png_get_huff_code (struct grub_png_data *data, struct huff_table *ht) +{ + int code, i; + + code = 0; + for (i = 0; i < ht->max_length; i++) + { + code = (code << 1) + grub_png_get_bits (data, 1); + if (code < ht->maxval[i]) + return ht->values[code + ht->offset[i]]; + } + return 0; +} + +static grub_err_t +grub_png_init_fixed_block (struct grub_png_data *data) +{ + int i; + + grub_png_init_huff_table (&data->code_table, DEFLATE_HUFF_LEN, + data->code_values, data->code_maxval, + data->code_offset); + + for (i = 0; i < 144; i++) + grub_png_insert_huff_item (&data->code_table, i, 8); + + for (; i < 256; i++) + grub_png_insert_huff_item (&data->code_table, i, 9); + + for (; i < 280; i++) + grub_png_insert_huff_item (&data->code_table, i, 7); + + for (; i < DEFLATE_HLIT_MAX; i++) + grub_png_insert_huff_item (&data->code_table, i, 8); + + grub_png_build_huff_table (&data->code_table); + + grub_png_init_huff_table (&data->dist_table, DEFLATE_HUFF_LEN, + data->dist_values, data->dist_maxval, + data->dist_offset); + + for (i = 0; i < DEFLATE_HDIST_MAX; i++) + grub_png_insert_huff_item (&data->dist_table, i, 5); + + grub_png_build_huff_table (&data->dist_table); + + return grub_errno; +} + +static grub_err_t +grub_png_init_dynamic_block (struct grub_png_data *data) +{ + int nl, nd, nb, i, prev; + struct huff_table cl; + int cl_values[sizeof (bitorder)]; + int cl_maxval[8]; + int cl_offset[8]; + grub_uint8_t lens[DEFLATE_HCLEN_MAX]; + + nl = DEFLATE_HLIT_BASE + grub_png_get_bits (data, 5); + nd = DEFLATE_HDIST_BASE + grub_png_get_bits (data, 5); + nb = DEFLATE_HCLEN_BASE + grub_png_get_bits (data, 4); + + if ((nl > DEFLATE_HLIT_MAX) || (nd > DEFLATE_HDIST_MAX) || + (nb > DEFLATE_HCLEN_MAX)) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, "png: too much data"); + + grub_png_init_huff_table (&cl, 8, cl_values, cl_maxval, cl_offset); + + for (i = 0; i < nb; i++) + lens[bitorder[i]] = grub_png_get_bits (data, 3); + + for (; i < DEFLATE_HCLEN_MAX; i++) + lens[bitorder[i]] = 0; + + for (i = 0; i < DEFLATE_HCLEN_MAX; i++) + grub_png_insert_huff_item (&cl, i, lens[i]); + + grub_png_build_huff_table (&cl); + + grub_png_init_huff_table (&data->code_table, DEFLATE_HUFF_LEN, + data->code_values, data->code_maxval, + data->code_offset); + + grub_png_init_huff_table (&data->dist_table, DEFLATE_HUFF_LEN, + data->dist_values, data->dist_maxval, + data->dist_offset); + + prev = 0; + for (i = 0; i < nl + nd; i++) + { + int n, code; + struct huff_table *ht; + + if (grub_errno) + return grub_errno; + + if (i < nl) + { + ht = &data->code_table; + code = i; + } + else + { + ht = &data->dist_table; + code = i - nl; + } + + n = grub_png_get_huff_code (data, &cl); + if (n < 16) + { + grub_png_insert_huff_item (ht, code, n); + prev = n; + } + else if (n == 16) + { + int c; + + c = 3 + grub_png_get_bits (data, 2); + while (c > 0) + { + grub_png_insert_huff_item (ht, code++, prev); + i++; + c--; + } + i--; + } + else if (n == 17) + i += 3 + grub_png_get_bits (data, 3) - 1; + else + i += 11 + grub_png_get_bits (data, 7) - 1; + } + + grub_png_build_huff_table (&data->code_table); + grub_png_build_huff_table (&data->dist_table); + + return grub_errno; +} + +static grub_err_t +grub_png_output_byte (struct grub_png_data *data, grub_uint8_t n) +{ + if (--data->raw_bytes < 0) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, "image size overflown"); + + if (data->cur_column == 0) + { + if (n >= PNG_FILTER_VALUE_LAST) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, "invalid filter value"); + + data->cur_filter = n; + } + else + *data->cur_rgb++ = n; + + data->cur_column++; + if (data->cur_column == data->row_bytes + 1) + { + grub_uint8_t *blank_line = NULL; + grub_uint8_t *cur = data->cur_rgb - data->row_bytes; + grub_uint8_t *left = cur; + grub_uint8_t *up; + + if (data->first_line) + { + blank_line = grub_zalloc (data->row_bytes); + if (blank_line == NULL) + return grub_errno; + + up = blank_line; + } + else + up = cur - data->row_bytes; + + switch (data->cur_filter) + { + case PNG_FILTER_VALUE_SUB: + { + int i; + + cur += data->bpp; + for (i = data->bpp; i < data->row_bytes; i++, cur++, left++) + *cur += *left; + + break; + } + case PNG_FILTER_VALUE_UP: + { + int i; + + for (i = 0; i < data->row_bytes; i++, cur++, up++) + *cur += *up; + + break; + } + case PNG_FILTER_VALUE_AVG: + { + int i; + + for (i = 0; i < data->bpp; i++, cur++, up++) + *cur += *up >> 1; + + for (; i < data->row_bytes; i++, cur++, up++, left++) + *cur += ((int) *up + (int) *left) >> 1; + + break; + } + case PNG_FILTER_VALUE_PAETH: + { + int i; + grub_uint8_t *upper_left = up; + + for (i = 0; i < data->bpp; i++, cur++, up++) + *cur += *up; + + for (; i < data->row_bytes; i++, cur++, up++, left++, upper_left++) + { + int a, b, c, pa, pb, pc; + + a = *left; + b = *up; + c = *upper_left; + + pa = b - c; + pb = a - c; + pc = pa + pb; + + if (pa < 0) + pa = -pa; + + if (pb < 0) + pb = -pb; + + if (pc < 0) + pc = -pc; + + *cur += ((pa <= pb) && (pa <= pc)) ? a : (pb <= pc) ? b : c; + } + } + } + + grub_free (blank_line); + + data->cur_column = 0; + data->first_line = 0; + } + + return grub_errno; +} + +static grub_err_t +grub_png_read_dynamic_block (struct grub_png_data *data) +{ + while (grub_errno == 0) + { + int n; + + n = grub_png_get_huff_code (data, &data->code_table); + if (n < 256) + { + data->slide[data->wp] = n; + grub_png_output_byte (data, n); + + data->wp++; + if (data->wp >= WSIZE) + data->wp = 0; + } + else if (n == 256) + break; + else + { + int len, dist, pos; + + n -= 257; + len = cplens[n]; + if (cplext[n]) + len += grub_png_get_bits (data, cplext[n]); + + n = grub_png_get_huff_code (data, &data->dist_table); + dist = cpdist[n]; + if (cpdext[n]) + dist += grub_png_get_bits (data, cpdext[n]); + + pos = data->wp - dist; + if (pos < 0) + pos += WSIZE; + + while (len > 0) + { + data->slide[data->wp] = data->slide[pos]; + grub_png_output_byte (data, data->slide[data->wp]); + + data->wp++; + if (data->wp >= WSIZE) + data->wp = 0; + + pos++; + if (pos >= WSIZE) + pos = 0; + + len--; + } + } + } + + return grub_errno; +} + +static grub_err_t +grub_png_decode_image_data (struct grub_png_data *data) +{ + grub_uint8_t cmf, flg; + int final; + + cmf = grub_png_get_byte (data); + flg = grub_png_get_byte (data); + + if ((cmf & 0xF) != Z_DEFLATED) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, + "png: only support deflate compression method"); + + if (flg & Z_FLAG_DICT) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, + "png: dictionary not supported"); + + do + { + int block_type; + + final = grub_png_get_bits (data, 1); + block_type = grub_png_get_bits (data, 2); + + switch (block_type) + { + case INFLATE_STORED: + { + grub_uint16_t i, len; + + data->bit_count = 0; + len = grub_png_get_byte (data); + len += ((grub_uint16_t) grub_png_get_byte (data)) << 8; + + /* Skip NLEN field. */ + grub_png_get_byte (data); + grub_png_get_byte (data); + + for (i = 0; i < len; i++) + grub_png_output_byte (data, grub_png_get_byte (data)); + + break; + } + + case INFLATE_FIXED: + grub_png_init_fixed_block (data); + grub_png_read_dynamic_block (data); + break; + + case INFLATE_DYNAMIC: + grub_png_init_dynamic_block (data); + grub_png_read_dynamic_block (data); + break; + + default: + return grub_error (GRUB_ERR_BAD_FILE_TYPE, + "png: unknown block type"); + } + } + while ((!final) && (grub_errno == 0)); + + /* Skip adler checksum. */ + grub_png_get_dword (data); + + /* Skip crc checksum. */ + grub_png_get_dword (data); + + return grub_errno; +} + +static const grub_uint8_t png_magic[8] = + { 0x89, 0x50, 0x4e, 0x47, 0xd, 0xa, 0x1a, 0x0a }; + +static void +grub_png_convert_image (struct grub_png_data *data) +{ + unsigned i; + grub_uint8_t *d1, *d2; + + d1 = (*data->bitmap)->data; + d2 = data->image_data + data->is_16bit; + +#ifndef GRUB_CPU_WORDS_BIGENDIAN +#define R4 3 +#define G4 2 +#define B4 1 +#define A4 0 +#define R3 2 +#define G3 1 +#define B3 0 +#else +#define R4 0 +#define G4 1 +#define B4 2 +#define A4 3 +#define R3 0 +#define G3 1 +#define B3 2 +#endif + + if (data->color_bits <= 4) + { + grub_uint8_t palette[16][3]; + grub_uint8_t *d1c, *d2c; + int shift; + int mask = (1 << data->color_bits) - 1; + unsigned j; + if (data->is_gray) + { + /* Generic formula is + (0xff * i) / ((1U << data->color_bits) - 1) + but for allowed bit depth of 1, 2 and for it's + equivalent to + (0xff / ((1U << data->color_bits) - 1)) * i + Precompute the multipliers to avoid division. + */ + + const grub_uint8_t multipliers[5] = { 0xff, 0xff, 0x55, 0x24, 0x11 }; + for (i = 0; i < (1U << data->color_bits); i++) + { + grub_uint8_t col = multipliers[data->color_bits] * i; + palette[i][0] = col; + palette[i][1] = col; + palette[i][2] = col; + } + } + else + grub_memcpy (palette, data->palette, 3 << data->color_bits); + d1c = d1; + d2c = d2; + for (j = 0; j < data->image_height; j++, d1c += data->image_width * 3, + d2c += data->row_bytes) + { + d1 = d1c; + d2 = d2c; + shift = 8 - data->color_bits; + for (i = 0; i < data->image_width; i++, d1 += 3) + { + grub_uint8_t col = (d2[0] >> shift) & mask; + d1[R3] = data->palette[col][2]; + d1[G3] = data->palette[col][1]; + d1[B3] = data->palette[col][0]; + shift -= data->color_bits; + if (shift < 0) + { + d2++; + shift += 8; + } + } + } + return; + } + + if (data->is_palette) + { + for (i = 0; i < (data->image_width * data->image_height); + i++, d1 += 3, d2++) + { + d1[R3] = data->palette[d2[0]][2]; + d1[G3] = data->palette[d2[0]][1]; + d1[B3] = data->palette[d2[0]][0]; + } + return; + } + + if (data->is_gray) + { + switch (data->bpp) + { + case 4: + /* 16-bit gray with alpha. */ + for (i = 0; i < (data->image_width * data->image_height); + i++, d1 += 4, d2 += 4) + { + d1[R4] = d2[3]; + d1[G4] = d2[3]; + d1[B4] = d2[3]; + d1[A4] = d2[1]; + } + break; + case 2: + if (data->is_16bit) + /* 16-bit gray without alpha. */ + { + for (i = 0; i < (data->image_width * data->image_height); + i++, d1 += 4, d2 += 2) + { + d1[R3] = d2[1]; + d1[G3] = d2[1]; + d1[B3] = d2[1]; + } + } + else + /* 8-bit gray with alpha. */ + { + for (i = 0; i < (data->image_width * data->image_height); + i++, d1 += 4, d2 += 2) + { + d1[R4] = d2[1]; + d1[G4] = d2[1]; + d1[B4] = d2[1]; + d1[A4] = d2[0]; + } + } + break; + /* 8-bit gray without alpha. */ + case 1: + for (i = 0; i < (data->image_width * data->image_height); + i++, d1 += 3, d2++) + { + d1[R3] = d2[0]; + d1[G3] = d2[0]; + d1[B3] = d2[0]; + } + break; + } + return; + } + + { + /* Only copy the upper 8 bit. */ +#ifndef GRUB_CPU_WORDS_BIGENDIAN + for (i = 0; i < (data->image_width * data->image_height * data->bpp >> 1); + i++, d1++, d2 += 2) + *d1 = *d2; +#else + switch (data->bpp) + { + /* 16-bit with alpha. */ + case 8: + for (i = 0; i < (data->image_width * data->image_height); + i++, d1 += 4, d2+=8) + { + d1[0] = d2[7]; + d1[1] = d2[5]; + d1[2] = d2[3]; + d1[3] = d2[1]; + } + break; + /* 16-bit without alpha. */ + case 6: + for (i = 0; i < (data->image_width * data->image_height); + i++, d1 += 3, d2+=6) + { + d1[0] = d2[5]; + d1[1] = d2[3]; + d1[2] = d2[1]; + } + break; + case 4: + /* 8-bit with alpha. */ + for (i = 0; i < (data->image_width * data->image_height); + i++, d1 += 4, d2 += 4) + { + d1[0] = d2[3]; + d1[1] = d2[2]; + d1[2] = d2[1]; + d1[3] = d2[0]; + } + break; + /* 8-bit without alpha. */ + case 3: + for (i = 0; i < (data->image_width * data->image_height); + i++, d1 += 3, d2 += 3) + { + d1[0] = d2[2]; + d1[1] = d2[1]; + d1[2] = d2[0]; + } + break; + } +#endif + } + +} + +static grub_err_t +grub_png_decode_png (struct grub_png_data *data) +{ + grub_uint8_t magic[8]; + + if (grub_file_read (data->file, &magic[0], 8) != 8) + return grub_errno; + + if (grub_memcmp (magic, png_magic, sizeof (png_magic))) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, "png: not a png file"); + + while (1) + { + grub_uint32_t len, type; + + len = grub_png_get_dword (data); + type = grub_png_get_dword (data); + data->next_offset = data->file->offset + len + 4; + + switch (type) + { + case PNG_CHUNK_IHDR: + grub_png_decode_image_header (data); + break; + + case PNG_CHUNK_PLTE: + grub_png_decode_image_palette (data, len); + break; + + case PNG_CHUNK_IDAT: + data->inside_idat = 1; + data->idat_remain = len; + data->bit_count = 0; + + grub_png_decode_image_data (data); + + data->inside_idat = 0; + break; + + case PNG_CHUNK_IEND: + if (data->image_data) + grub_png_convert_image (data); + + return grub_errno; + + default: + grub_file_seek (data->file, data->file->offset + len + 4); + } + + if (grub_errno) + break; + + if (data->file->offset != data->next_offset) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, + "png: chunk size error"); + } + + return grub_errno; +} + +static grub_err_t +grub_video_reader_png (struct grub_video_bitmap **bitmap, + const char *filename) +{ + grub_file_t file; + struct grub_png_data *data; + + file = grub_buffile_open (filename, GRUB_FILE_TYPE_PIXMAP, 0); + if (!file) + return grub_errno; + + data = grub_zalloc (sizeof (*data)); + if (data != NULL) + { + data->file = file; + data->bitmap = bitmap; + + grub_png_decode_png (data); + + grub_free (data->image_data); + grub_free (data); + } + + if (grub_errno != GRUB_ERR_NONE) + { + grub_video_bitmap_destroy (*bitmap); + *bitmap = 0; + } + + grub_file_close (file); + return grub_errno; +} + +#if defined(PNG_DEBUG) +static grub_err_t +grub_cmd_pngtest (grub_command_t cmd_d __attribute__ ((unused)), + int argc, char **args) +{ + struct grub_video_bitmap *bitmap = 0; + + if (argc != 1) + return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected")); + + grub_video_reader_png (&bitmap, args[0]); + if (grub_errno != GRUB_ERR_NONE) + return grub_errno; + + grub_video_bitmap_destroy (bitmap); + + return GRUB_ERR_NONE; +} +#endif + +static struct grub_video_bitmap_reader png_reader = { + .extension = ".png", + .reader = grub_video_reader_png, + .next = 0 +}; + +GRUB_MOD_INIT (png) +{ + grub_video_bitmap_reader_register (&png_reader); +#if defined(PNG_DEBUG) + cmd = grub_register_command ("pngtest", grub_cmd_pngtest, + "FILE", + "Tests loading of PNG bitmap."); +#endif +} + +GRUB_MOD_FINI (png) +{ +#if defined(PNG_DEBUG) + grub_unregister_command (cmd); +#endif + grub_video_bitmap_reader_unregister (&png_reader); +} |