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#include "../engine/client/pnglite/pnglite.c"
typedef struct pixel_t
{
unsigned char r, g, b, a;
} pixel;
static int clamp(int v, int min, int max)
{
if(v > max)
return max;
if(v < min)
return min;
return v;
}
static void dilate(int w, int h, pixel *src, pixel *dst)
{
int x, y, k, m, c;
int ix, iy;
m = 0;
for(y = 0; y < h; y++)
{
for(x = 0; x < w; x++, m++)
{
dst[m] = src[m];
if(src[m].a)
continue;
const int xo[] = {0, -1, 1, 0};
const int yo[] = {-1, 0, 0, 1};
for(c = 0; c < 4; c++)
{
ix = clamp(x + xo[c], 0, w-1);
iy = clamp(y + yo[c], 0, h-1);
k = iy*w+ix;
if(src[k].a)
{
dst[m] = src[k];
dst[m].a = 255;
break;
}
}
}
}
}
static void copy_alpha(int w, int h, pixel *src, pixel *dst)
{
int x, y, m;
for(y = 0; y < h; y++)
for(x = 0; x < w; x++, m++)
dst[m].a = src[m].a;
}
int main(int argc, char **argv)
{
png_t png;
pixel *buffer[3] = {0,0,0};
int i, w, h;
png_init(0,0);
png_open_file(&png, argv[1]);
if(png.color_type != PNG_TRUECOLOR_ALPHA)
{
printf("not an RGBA image\n");
return -1;
}
buffer[0] = (pixel*)malloc(png.width*png.height*sizeof(pixel));
buffer[1] = (pixel*)malloc(png.width*png.height*sizeof(pixel));
buffer[2] = (pixel*)malloc(png.width*png.height*sizeof(pixel));
png_get_data(&png, (unsigned char *)buffer[0]);
png_close_file(&png);
w = png.width;
h = png.height;
dilate(w, h, buffer[0], buffer[1]);
for(i = 0; i < 5; i++)
{
dilate(w, h, buffer[1], buffer[2]);
dilate(w, h, buffer[2], buffer[1]);
}
copy_alpha(w, h, buffer[0], buffer[1]);
// save here
png_open_file_write(&png, argv[1]);
png_set_data(&png, w, h, 8, PNG_TRUECOLOR_ALPHA, (unsigned char *)buffer[1]);
png_close_file(&png);
return 0;
}
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