ugfx/3rdparty/tinygl-0.4-ugfx/src/image_util.c

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2014-08-19 15:36:33 +00:00
#include "zgl.h"
/*
* image conversion
*/
void gl_convertRGB_to_5R6G5B(unsigned short *pixmap,unsigned char *rgb,
int xsize,int ysize)
{
int i,n;
unsigned char *p;
p=rgb;
n=xsize*ysize;
for(i=0;i<n;i++) {
pixmap[i]=((p[0]&0xF8)<<8) | ((p[1]&0xFC)<<3) | ((p[2]&0xF8)>>3);
p+=3;
}
}
void gl_convertRGB_to_8A8R8G8B(unsigned int *pixmap, unsigned char *rgb,
int xsize, int ysize)
{
int i,n;
unsigned char *p;
p=rgb;
n=xsize*ysize;
for(i=0;i<n;i++) {
pixmap[i]=(((unsigned int)p[0])<<16) |
(((unsigned int)p[1])<<8) |
(((unsigned int)p[2]));
p+=3;
}
}
/*
* linear interpolation with xf,yf normalized to 2^16
*/
#define INTERP_NORM_BITS 16
#define INTERP_NORM (1 << INTERP_NORM_BITS)
static inline int interpolate(int v00,int v01,int v10,int xf,int yf)
{
return v00+(((v01-v00)*xf + (v10-v00)*yf) >> INTERP_NORM_BITS);
}
/*
* TODO: more accurate resampling
*/
void gl_resizeImage(unsigned char *dest,int xsize_dest,int ysize_dest,
unsigned char *src,int xsize_src,int ysize_src)
{
unsigned char *pix,*pix_src;
float x1,y1,x1inc,y1inc;
int xi,yi,j,xf,yf,x,y;
pix=dest;
pix_src=src;
x1inc=(float) (xsize_src - 1) / (float) (xsize_dest - 1);
y1inc=(float) (ysize_src - 1) / (float) (ysize_dest - 1);
y1=0;
for(y=0;y<ysize_dest;y++) {
x1=0;
for(x=0;x<xsize_dest;x++) {
xi=(int) x1;
yi=(int) y1;
xf=(int) ((x1 - floor(x1)) * INTERP_NORM);
yf=(int) ((y1 - floor(y1)) * INTERP_NORM);
if ((xf+yf) <= INTERP_NORM) {
for(j=0;j<3;j++) {
pix[j]=interpolate(pix_src[(yi*xsize_src+xi)*3+j],
pix_src[(yi*xsize_src+xi+1)*3+j],
pix_src[((yi+1)*xsize_src+xi)*3+j],
xf,yf);
}
} else {
xf=INTERP_NORM - xf;
yf=INTERP_NORM - yf;
for(j=0;j<3;j++) {
pix[j]=interpolate(pix_src[((yi+1)*xsize_src+xi+1)*3+j],
pix_src[((yi+1)*xsize_src+xi)*3+j],
pix_src[(yi*xsize_src+xi+1)*3+j],
xf,yf);
}
}
pix+=3;
x1+=x1inc;
}
y1+=y1inc;
}
}
#define FRAC_BITS 16
/* resizing with no interlating nor nearest pixel */
void gl_resizeImageNoInterpolate(unsigned char *dest,int xsize_dest,int ysize_dest,
unsigned char *src,int xsize_src,int ysize_src)
{
unsigned char *pix,*pix_src,*pix1;
int x1,y1,x1inc,y1inc;
int xi,yi,x,y;
pix=dest;
pix_src=src;
x1inc=(int)((float) ((xsize_src)<<FRAC_BITS) / (float) (xsize_dest));
y1inc=(int)((float) ((ysize_src)<<FRAC_BITS) / (float) (ysize_dest));
y1=0;
for(y=0;y<ysize_dest;y++) {
x1=0;
for(x=0;x<xsize_dest;x++) {
xi=x1 >> FRAC_BITS;
yi=y1 >> FRAC_BITS;
pix1=pix_src+(yi*xsize_src+xi)*3;
pix[0]=pix1[0];
pix[1]=pix1[1];
pix[2]=pix1[2];
pix+=3;
x1+=x1inc;
}
y1+=y1inc;
}
}