root/lib/gfximage.c

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DEFINITIONS

This source file includes following definitions.
  1. gfximage_new
  2. gfximage_save_jpeg
  3. gfximage_save_png
  4. make_scale_lookup
  5. encodeMonochromeImage
  6. decodeMonochromeImage
  7. blurImage
  8. swf_ImageGetNumberOfPaletteEntries2
  9. gfximage_rescale
  10. gfximage_free

#include <stdlib.h>
#include <math.h>
#include <memory.h>
#include "jpeg.h"
#include "png.h"
#include "mem.h"
#include "gfximage.h"
#include "types.h"

gfximage_t*gfximage_new(int width, int height)
{
    gfximage_t*i = rfx_calloc(sizeof(gfximage_t));
    i->data = rfx_calloc(width*height*4);
    i->width = width;
    i->height = height;
    return i;
}

void gfximage_save_jpeg(gfximage_t*img, const char*filename, int quality)
{
    int x,y;
    int l = img->width*img->height;
    unsigned char*data = (unsigned char*)rfx_alloc(img->width*img->height*3);
    int s,t;
    for(t=0,s=0;t<l;s+=3,t++) {
        data[s+0] = img->data[t].r;
        data[s+1] = img->data[t].g;
        data[s+2] = img->data[t].b;
    }
    jpeg_save(data, img->width, img->height, quality, filename);
    free(data);
}

void gfximage_save_png(gfximage_t*image, const char*filename)
{
    writePNG(filename, (void*)image->data, image->width, image->height);
}

typedef struct scale_lookup {
    int pos;
    unsigned int weight;
} scale_lookup_t;

typedef struct rgba_int {
    unsigned int r,g,b,a;
} rgba_int_t;

static int bicubic = 0;

static scale_lookup_t**make_scale_lookup(int width, int newwidth)
{
    scale_lookup_t*lookupx = (scale_lookup_t*)rfx_alloc((width>newwidth?width:newwidth)*2*sizeof(scale_lookup_t));
    scale_lookup_t**lblockx = (scale_lookup_t**)rfx_alloc((newwidth+1)*sizeof(scale_lookup_t**));
    double fx = ((double)width)/((double)newwidth);
    double px = 0;
    int x;
    scale_lookup_t*p_x = lookupx;

    if(newwidth<=width) {
        for(x=0;x<newwidth;x++) {
            double ex = px + fx;
            int fromx = (int)px;
            int tox = (int)ex;
            double rem = fromx+1-px;
            int i = (int)(256/fx);
            int xweight = (int)(rem*256/fx);
            int xx;
            int w = 0;
            lblockx[x] = p_x;
            if(tox>=width) tox = width-1;
            for(xx=fromx;xx<=tox;xx++) {
                if(xx==fromx && xx==tox) p_x->weight = 256;
                else if(xx==fromx) p_x->weight = xweight;
                else if(xx==tox) p_x->weight = 256-w;
                else p_x->weight = i;
                w+=p_x->weight;
                p_x->pos = xx;
                p_x++;
            }
            px = ex;
        }
    } else {
        for(x=0;x<newwidth;x++) {
            int ix1 = (int)px;
            int ix2 = ((int)px)+1;
            double r = px-ix1;
            if(ix2>=width) ix2=width-1;
            lblockx[x] = p_x;
            if(bicubic)
                r = -2*r*r*r+3*r*r;
            p_x[0].weight = (int)(256*(1-r));
            p_x[0].pos = ix1;
            p_x[1].weight = 256-p_x[0].weight;
            p_x[1].pos = ix2;
            p_x+=2;
            px += fx;
        }
    }
    lblockx[newwidth] = p_x;
    return lblockx;
}

static void encodeMonochromeImage(gfxcolor_t*data, int width, int height, gfxcolor_t*colors)
{
    int t;
    int len = width*height;

    U32* img = (U32*)data;
    U32 color1 = img[0];
    U32 color2 = 0;
    for(t=1;t<len;t++) {
        if(img[t] != color1) {
            color2 = img[t];
            break;
        }
    }
    *(U32*)&colors[0] = color1;
    *(U32*)&colors[1] = color2;
    for(t=0;t<len;t++) {
        if(img[t] == color1) {
            img[t] = 0;
        } else {
            img[t] = 0xffffffff;
        }
    }
}

static void decodeMonochromeImage(gfxcolor_t*data, int width, int height, gfxcolor_t*colors)
{
    int t;
    int len = width*height;

    for(t=0;t<len;t++) {
        U32 m = data[t].r;
        data[t].r = (colors[0].r * (255-m) + colors[1].r * m) >> 8;
        data[t].g = (colors[0].g * (255-m) + colors[1].g * m) >> 8;
        data[t].b = (colors[0].b * (255-m) + colors[1].b * m) >> 8;
        data[t].a = (colors[0].a * (255-m) + colors[1].a * m) >> 8;
    }
}

void blurImage(gfxcolor_t*src, int width, int height, int r)  __attribute__ ((noinline));

void blurImage(gfxcolor_t*src, int width, int height, int r)
{
    int e = 2; // r times e is the sampling interval
    double*gauss = (double*)rfx_alloc(r*e*sizeof(double));
    double sum=0;
    int x;
    for(x=0;x<r*e;x++) {
        double t = (x - r*e/2.0)/r;
        gauss[x] = exp(-0.5*t*t);
        sum += gauss[x];
    }
    int*weights = (int*)rfx_alloc(r*e*sizeof(int));
    for(x=0;x<r*e;x++) {
        weights[x] = (int)(gauss[x]*65536.0001/sum);
    }
    int range = r*e/2;

    gfxcolor_t*tmp = rfx_alloc(sizeof(gfxcolor_t)*width*height);

    int y;
    for(y=0;y<height;y++) {
        gfxcolor_t*s = &src[y*width];
        gfxcolor_t*d = &tmp[y*width];
        for(x=0;x<range && x<width;x++) {
            d[x] = s[x];
        }
        for(;x<width-range;x++) {
            int r=0;
            int g=0;
            int b=0;
            int a=0;
            int*f = weights;
            int xx;
            for(xx=x-range;xx<x+range;xx++) {
                r += s[xx].r * f[0];
                g += s[xx].g * f[0];
                b += s[xx].b * f[0];
                a += s[xx].a * f[0];
                f++;
            }
            d[x].r = r >> 16;
            d[x].g = g >> 16;
            d[x].b = b >> 16;
            d[x].a = a >> 16;
        }
        for(;x<width;x++) {
            d[x] = s[x];
        }
    }

    for(x=0;x<width;x++) {
        gfxcolor_t*s = &tmp[x];
        gfxcolor_t*d = &src[x];
        int yy=0;
        for(y=0;y<range&&y<height;y++) {
            d[yy] = s[yy];
            yy+=width;
        }
        for(;y<height-range;y++) {
            int r=0;
            int g=0;
            int b=0;
            int a=0;
            int*f = weights;
            int cy,cyy=yy-range*width;
            for(cy=y-range;cy<y+range;cy++) {
                r += s[cyy].r * f[0];
                g += s[cyy].g * f[0];
                b += s[cyy].b * f[0];
                a += s[cyy].a * f[0];
                cyy += width;
                f++;
            }
            d[yy].r = r >> 16;
            d[yy].g = g >> 16;
            d[yy].b = b >> 16;
            d[yy].a = a >> 16;
            yy += width;
        }
        for(;y<height;y++) {
            d[yy] = s[yy];
            yy += width;
        }
    }

    rfx_free(tmp);
    rfx_free(weights);
    rfx_free(gauss);
}

int swf_ImageGetNumberOfPaletteEntries2(gfxcolor_t*_img, int width, int height)
{
    int len = width*height;
    int t;
    U32* img = (U32*)_img;
    U32 color1 = img[0];
    U32 color2 = 0;
    for(t=1;t<len;t++) {
        if(img[t] != color1) {
            color2 = img[t];
            break;
        }
    }
    if(t==len)
        return 1;

    for(;t<len;t++) {
        if(img[t] != color1 && img[t] != color2) {
            return width*height;
        }
    }
    return 2;
}

gfximage_t* gfximage_rescale(gfximage_t*image, int newwidth, int newheight)
{
    int x,y;
    gfxcolor_t* newdata; 
    scale_lookup_t *p, **lblockx,**lblocky;
    rgba_int_t*tmpline;
    int monochrome = 0;
    gfxcolor_t monochrome_colors[2];
   
    if(newwidth<1)
        newwidth=1;
    if(newheight<1)
        newheight=1;

    int width = image->width;
    int height = image->height;
    gfxcolor_t*data = image->data;

    if(swf_ImageGetNumberOfPaletteEntries2(data, width, height) == 2) {
        monochrome=1;
        encodeMonochromeImage(data, width, height, monochrome_colors);
        int r1 = width / newwidth;
        int r2 = height / newheight;
        int r = r1<r2?r1:r2;
        if(r>4) {
            /* high-resolution monochrome images are usually dithered, so 
               low-pass filter them first to get rid of any moire patterns */
            blurImage(data, width, height, r+1);
        }
    }

    tmpline = (rgba_int_t*)rfx_alloc(width*sizeof(rgba_int_t));
    newdata = (gfxcolor_t*)rfx_alloc(newwidth*newheight*sizeof(gfxcolor_t));
  
    lblockx = make_scale_lookup(width, newwidth);
    lblocky = make_scale_lookup(height, newheight);

    for(p=lblocky[0];p<lblocky[newheight];p++)
        p->pos*=width;

    for(y=0;y<newheight;y++) {
        gfxcolor_t*destline = &newdata[y*newwidth];
        
        /* create lookup table for y */
        rgba_int_t*l = tmpline;
        scale_lookup_t*p_y,*p_x;
        memset(tmpline, 0, width*sizeof(rgba_int_t));
        for(p_y=lblocky[y];p_y<lblocky[y+1];p_y++) {
            gfxcolor_t*line = &data[p_y->pos];
            scale_lookup_t*p_x;
            int weight = p_y->weight;
            for(x=0;x<width;x++) {
                tmpline[x].r += line[x].r*weight;
                tmpline[x].g += line[x].g*weight;
                tmpline[x].b += line[x].b*weight;
                tmpline[x].a += line[x].a*weight;
            }
        }

        /* process x direction */
        p_x = lblockx[0];
        for(x=0;x<newwidth;x++) {
            unsigned int r=0,g=0,b=0,a=0;
            scale_lookup_t*p_x_to = lblockx[x+1];
            do { 
                rgba_int_t* col = &tmpline[p_x->pos];
                unsigned int weight = p_x->weight;
                r += col->r*weight;
                g += col->g*weight;
                b += col->b*weight;
                a += col->a*weight;
                p_x++;
            } while (p_x<p_x_to);

            destline->r = r >> 16;
            destline->g = g >> 16;
            destline->b = b >> 16;
            destline->a = a >> 16;
           
            destline++;
        }
    }

    if(monochrome)
        decodeMonochromeImage(newdata, newwidth, newheight, monochrome_colors);

    rfx_free(tmpline);
    rfx_free(*lblockx);
    rfx_free(lblockx);
    rfx_free(*lblocky);
    rfx_free(lblocky);

    gfximage_t*image2 = (gfximage_t*)malloc(sizeof(gfximage_t));
    image2->data = newdata;
    image2->width = newwidth;
    image2->height = newheight;
    return image2;
}

void gfximage_free(gfximage_t*b)
{
    free(b->data);
    b->data = 0;
    free(b);
}


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