79 lines
1.9 KiB
C
79 lines
1.9 KiB
C
#include <stdint.h>
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#include <fs/file.h>
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#include <lib/image.h>
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#include <lib/bmp.h>
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#include <lib/libc.h>
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#include <lib/blib.h>
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#include <mm/pmm.h>
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struct bmp_header {
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uint16_t bf_signature;
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uint32_t bf_size;
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uint32_t reserved;
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uint32_t bf_offset;
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uint32_t bi_size;
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uint32_t bi_width;
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uint32_t bi_height;
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uint16_t bi_planes;
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uint16_t bi_bpp;
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uint32_t bi_compression;
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uint32_t bi_image_size;
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uint32_t bi_xcount;
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uint32_t bi_ycount;
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uint32_t bi_clr_used;
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uint32_t bi_clr_important;
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uint32_t red_mask;
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uint32_t green_mask;
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uint32_t blue_mask;
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} __attribute__((packed));
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struct bmp_local {
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uint8_t *image;
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uint32_t pitch;
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struct bmp_header header;
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};
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static uint32_t get_pixel(struct image *this, int x, int y) {
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struct bmp_local *local = this->local;
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struct bmp_header *header = &local->header;
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x %= header->bi_width;
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y %= header->bi_height;
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size_t pixel_offset = local->pitch * (header->bi_height - y - 1) + x * (header->bi_bpp / 8);
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uint32_t composite = 0;
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for (int i = 0; i < header->bi_bpp / 8; i++)
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composite |= (uint32_t)local->image[pixel_offset + i] << (i * 8);
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return composite;
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}
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int bmp_open_image(struct image *image, struct file_handle *file) {
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struct bmp_header header;
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fread(file, &header, 0, sizeof(struct bmp_header));
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if (memcmp(&header.bf_signature, "BM", 2) != 0)
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return -1;
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// We don't support bpp lower than 8
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if (header.bi_bpp < 8)
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return -1;
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struct bmp_local *local = ext_mem_alloc(sizeof(struct bmp_local));
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local->image = ext_mem_alloc(header.bf_size);
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fread(file, local->image, header.bf_offset, header.bf_size);
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local->pitch = ALIGN_UP(header.bi_width * header.bi_bpp, 32) / 8;
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local->header = header;
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image->x_size = header.bi_width;
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image->y_size = header.bi_height;
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image->get_pixel = get_pixel;
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image->local = local;
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return 0;
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}
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