rulimine/common/lib/bmp.c

64 lines
1.6 KiB
C

#include <stdint.h>
#include <fs/file.h>
#include <lib/image.h>
#include <lib/bmp.h>
#include <lib/libc.h>
#include <lib/misc.h>
#include <mm/pmm.h>
struct bmp_header {
uint16_t bf_signature;
uint32_t bf_size;
uint32_t reserved;
uint32_t bf_offset;
uint32_t bi_size;
uint32_t bi_width;
uint32_t bi_height;
uint16_t bi_planes;
uint16_t bi_bpp;
uint32_t bi_compression;
uint32_t bi_image_size;
uint32_t bi_xcount;
uint32_t bi_ycount;
uint32_t bi_clr_used;
uint32_t bi_clr_important;
uint32_t red_mask;
uint32_t green_mask;
uint32_t blue_mask;
} __attribute__((packed));
bool bmp_open_image(struct image *image, struct file_handle *file) {
struct bmp_header header;
fread(file, &header, 0, sizeof(struct bmp_header));
if (memcmp(&header.bf_signature, "BM", 2) != 0)
return false;
// We don't support bpp lower than 8
if (header.bi_bpp % 8 != 0)
return false;
image->img = ext_mem_alloc(header.bf_size);
uint32_t bf_size;
if (header.bf_offset + header.bf_size > file->size) {
bf_size = file->size - header.bf_offset;
} else {
bf_size = header.bf_size;
}
fread(file, image->img, header.bf_offset, bf_size);
image->allocated_size = header.bf_size;
image->x_size = header.bi_width;
image->y_size = header.bi_height;
image->pitch = ALIGN_UP(header.bi_width * header.bi_bpp, 32) / 8;
image->bpp = header.bi_bpp;
image->img_width = header.bi_width;
image->img_height = header.bi_height;
return true;
}