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Removed blur.cc since it is currently not used

v1.x
Tj Holowaychuk 14 years ago
parent
commit
c95cf16053
  1. 72
      src/blur.cc

72
src/blur.cc

@ -1,72 +0,0 @@
#include <math.h>
#include <memory.h>
#include <stdint.h>
#include <stdlib.h>
#include <cairo.h>
#include "canvas.h"
void
Canvas::blur(cairo_surface_t *surface, int radius) {
// Steve Hanov, 2009
// Released into the public domain.
// get width, height
int width = cairo_image_surface_get_width( surface );
int height = cairo_image_surface_get_height( surface );
unsigned char* dst = (unsigned char*)malloc(width*height*4);
unsigned* precalc =
(unsigned*)malloc(width*height*sizeof(unsigned));
unsigned char* src = cairo_image_surface_get_data( surface );
double mul=1.f/((radius*2)*(radius*2));
int channel;
// The number of times to perform the averaging. According to wikipedia,
// three iterations is good enough to pass for a gaussian.
const int MAX_ITERATIONS = 3;
int iteration;
memcpy( dst, src, width*height*4 );
for ( iteration = 0; iteration < MAX_ITERATIONS; iteration++ ) {
for( channel = 0; channel < 4; channel++ ) {
int x,y;
// precomputation step.
unsigned char* pix = src;
unsigned* pre = precalc;
pix += channel;
for (y=0;y<height;y++) {
for (x=0;x<width;x++) {
int tot=pix[0];
if (x>0) tot+=pre[-1];
if (y>0) tot+=pre[-width];
if (x>0 && y>0) tot-=pre[-width-1];
*pre++=tot;
pix += 4;
}
}
// blur step.
pix = dst + (int)radius * width * 4 + (int)radius * 4 + channel;
for (y=radius;y<height-radius;y++) {
for (x=radius;x<width-radius;x++) {
int l = x < radius ? 0 : x - radius;
int t = y < radius ? 0 : y - radius;
int r = x + radius >= width ? width - 1 : x + radius;
int b = y + radius >= height ? height - 1 : y + radius;
int tot = precalc[r+b*width] + precalc[l+t*width] -
precalc[l+b*width] - precalc[r+t*width];
*pix=(unsigned char)(tot*mul);
pix += 4;
}
pix += (int)radius * 2 * 4;
}
}
memcpy( src, dst, width*height*4 );
}
free( dst );
free( precalc );
}
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