87 lines
1.8 KiB
C
87 lines
1.8 KiB
C
#include <libimg.h>
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#include "libimg-internal.h"
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static void img_rotate_90(img_t src, img_t dst)
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{
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if(!img_target(dst, src.height, src.width)) return;
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img_pixel_t *src_px = src.pixels;
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img_pixel_t *dst_px = dst.pixels + src.height - 1;
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for(int y = 0; y < src.height; y++)
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{
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for(int x=0, dy=0; x < src.width; x++, dy+=dst.stride)
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if(src_px[x] != IMG_ALPHA)
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dst_px[dy] = src_px[x];
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src_px += src.stride;
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dst_px--;
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}
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}
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static void img_rotate_180(img_t src, img_t dst)
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{
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if(!img_target(dst, src.width, src.height)) return;
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img_pixel_t *src_px = src.pixels;
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img_pixel_t *dst_px = dst.pixels + (src.height - 1) * dst.stride +
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src.width - 1;
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for(int y = 0; y < src.height; y++)
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{
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for(int x=0; x < src.width; x++)
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if(src_px[x] != IMG_ALPHA)
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dst_px[-x] = src_px[x];
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src_px += src.stride;
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dst_px -= dst.stride;
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}
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}
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static void img_rotate_270(img_t src, img_t dst)
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{
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if(!img_target(dst, src.height, src.width)) return;
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img_pixel_t *src_px = src.pixels;
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img_pixel_t *dst_px = dst.pixels + (src.width - 1) * dst.stride;
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for(int y = 0; y < src.height; y++)
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{
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for(int x=0, dy=0; x < src.width; x++, dy+=dst.stride)
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if(src_px[x] != IMG_ALPHA)
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dst_px[-dy] = src_px[x];
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src_px += src.stride;
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dst_px++;
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}
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}
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void img_rotate(img_t src, img_t dst, int angle)
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{
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if(src.pixels == dst.pixels)
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{
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img_rotate_inplace(src, angle);
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return;
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}
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if(angle == 0)
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{
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if(!img_target(dst, src.width, src.height)) return;
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img_render(src, dst);
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}
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if(angle == 90) img_rotate_90(src, dst);
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if(angle == 180) img_rotate_180(src, dst);
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if(angle == 270) img_rotate_270(src, dst);
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}
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img_t img_rotate_create(img_t src, int angle)
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{
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int w = src.width, h = src.height;
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if(angle == 90 || angle == 270) w = src.height, h = src.width;
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img_t dst = img_create(w, h);
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img_fill(dst, IMG_ALPHA);
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img_rotate(src, dst, angle);
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return dst;
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}
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