1.1 --- a/src/image.cc	Tue Jul 07 21:56:37 2015 +0300
     1.2 +++ b/src/image.cc	Wed Jul 08 02:31:36 2015 +0300
     1.3 @@ -1,4 +1,5 @@
     1.4  #include <string.h>
     1.5 +#include <alloca.h>
     1.6  #include "opengl.h"
     1.7  #include "image.h"
     1.8  #include "imago2.h"
     1.9 @@ -233,6 +234,119 @@
    1.10  	return true;
    1.11  }
    1.12  
    1.13 +void convolve_horiz_image(Image *dest, float *kern, int ksz, float scale)
    1.14 +{
    1.15 +	if((ksz & 1) == 0) {
    1.16 +		fprintf(stderr, "%s: kernel size (%d) must be odd, skipping last value\n", __FUNCTION__, ksz);
    1.17 +		--ksz;
    1.18 +	}
    1.19 +	if(scale == 0.0) {
    1.20 +		// calculate scale factor
    1.21 +		float sum = 0.0;
    1.22 +		for(int i=0; i<ksz; i++) {
    1.23 +			sum += kern[i];
    1.24 +		}
    1.25 +		scale = 1.0 / sum;
    1.26 +	}
    1.27 +	int krad = ksz / 2;
    1.28 +	float *buf = (float*)alloca(dest->width * 4 * sizeof *buf);
    1.29 +	unsigned char *sptr = dest->pixels;
    1.30 +
    1.31 +	for(int i=0; i<dest->height; i++) {
    1.32 +		float *bptr = buf;
    1.33 +		for(int j=0; j<dest->width * 4; j++) {
    1.34 +			*bptr++ = (float)(sptr[j] / 255.0);
    1.35 +		}
    1.36 +
    1.37 +		for(int j=0; j<dest->width; j++) {
    1.38 +			float col[] = {0, 0, 0, 0};
    1.39 +
    1.40 +			for(int k=0; k<ksz; k++) {
    1.41 +				int idx = j + k - krad;
    1.42 +				if(idx < 0) idx = 0;
    1.43 +				if(idx >= dest->width) idx = dest->width - 1;
    1.44 +
    1.45 +				col[0] += buf[idx * 4] * kern[k];
    1.46 +				col[1] += buf[idx * 4 + 1] * kern[k];
    1.47 +				col[2] += buf[idx * 4 + 2] * kern[k];
    1.48 +				col[3] += buf[idx * 4 + 3] * kern[k];
    1.49 +			}
    1.50 +
    1.51 +			int ri = (int)(col[0] * scale * 255.0);
    1.52 +			int gi = (int)(col[1] * scale * 255.0);
    1.53 +			int bi = (int)(col[2] * scale * 255.0);
    1.54 +			int ai = (int)(col[3] * scale * 255.0);
    1.55 +
    1.56 +			sptr[0] = ri < 0 ? 0 : (ri > 255 ? 255 : ri);
    1.57 +			sptr[1] = gi < 0 ? 0 : (gi > 255 ? 255 : gi);
    1.58 +			sptr[2] = bi < 0 ? 0 : (bi > 255 ? 255 : bi);
    1.59 +			sptr[3] = ai < 0 ? 0 : (ai > 255 ? 255 : ai);
    1.60 +			sptr += 4;
    1.61 +		}
    1.62 +	}
    1.63 +
    1.64 +	dest->invalidate_texture();
    1.65 +}
    1.66 +
    1.67 +void convolve_vert_image(Image *dest, float *kern, int ksz, float scale)
    1.68 +{
    1.69 +	if((ksz & 1) == 0) {
    1.70 +		fprintf(stderr, "%s: kernel size (%d) must be odd, skipping last value\n", __FUNCTION__, ksz);
    1.71 +		--ksz;
    1.72 +	}
    1.73 +	if(scale == 0.0) {
    1.74 +		// calculate scale factor
    1.75 +		float sum = 0.0;
    1.76 +		for(int i=0; i<ksz; i++) {
    1.77 +			sum += kern[i];
    1.78 +		}
    1.79 +		scale = 1.0 / sum;
    1.80 +	}
    1.81 +	int krad = ksz / 2;
    1.82 +	float *buf = (float*)alloca(dest->height * 4 * sizeof *buf);
    1.83 +	unsigned char *sptr = dest->pixels;
    1.84 +
    1.85 +	for(int i=0; i<dest->width; i++) {
    1.86 +		float *bptr = buf;
    1.87 +		sptr = dest->pixels + i * 4;
    1.88 +
    1.89 +		for(int j=0; j<dest->height; j++) {
    1.90 +			for(int k=0; k<4; k++) {
    1.91 +				*bptr++ = (float)(sptr[k] / 255.0);
    1.92 +			}
    1.93 +			sptr += dest->width * 4;
    1.94 +		}
    1.95 +
    1.96 +		sptr = dest->pixels + i * 4;
    1.97 +
    1.98 +		for(int j=0; j<dest->height; j++) {
    1.99 +			float col[] = {0, 0, 0, 0};
   1.100 +
   1.101 +			for(int k=0; k<ksz; k++) {
   1.102 +				int idx = j + k - krad;
   1.103 +				if(idx < 0) idx = 0;
   1.104 +				if(idx >= dest->height) idx = dest->height - 1;
   1.105 +
   1.106 +				col[0] += buf[idx * 4] * kern[k];
   1.107 +				col[1] += buf[idx * 4 + 1] * kern[k];
   1.108 +				col[2] += buf[idx * 4 + 2] * kern[k];
   1.109 +				col[3] += buf[idx * 4 + 3] * kern[k];
   1.110 +			}
   1.111 +
   1.112 +			int ri = (int)(col[0] * scale * 255.0);
   1.113 +			int gi = (int)(col[1] * scale * 255.0);
   1.114 +			int bi = (int)(col[2] * scale * 255.0);
   1.115 +			int ai = (int)(col[3] * scale * 255.0);
   1.116 +
   1.117 +			sptr[0] = ri < 0 ? 0 : (ri > 255 ? 255 : ri);
   1.118 +			sptr[1] = gi < 0 ? 0 : (gi > 255 ? 255 : gi);
   1.119 +			sptr[2] = bi < 0 ? 0 : (bi > 255 ? 255 : bi);
   1.120 +			sptr[3] = ai < 0 ? 0 : (ai > 255 ? 255 : ai);
   1.121 +			sptr += dest->width * 4;
   1.122 +		}
   1.123 +	}
   1.124 +}
   1.125 +
   1.126  static unsigned int next_pow2(unsigned int x)
   1.127  {
   1.128  	x--;