/* set.c */
/************************************************************************
Part of the dvipng distribution
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation, either version 3 of the
License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this program. If not, see
<http://www.gnu.org/licenses/>.
Copyright (C) 2002-2015 Jan-�ke Larsson
************************************************************************/
#include "dvipng.h"
#include <math.h>
#ifndef HAVE_GDIMAGECREATETRUECOLOR
#define gdImageColorAllocateAlpha(i,r,g,b,a) gdImageColorAllocate(i,r,g,b)
#define gdImageColorResolveAlpha(i,r,g,b,a) gdImageColorResolve(i,r,g,b)
#define gdImageAlpha(i,c) 0
#define gdAlphaMax 127
#endif
#ifndef HAVE_GDIMAGEPNGEX
#define gdImagePngEx(i,f,z) gdImagePng(i,f)
#endif
/* Persistent color cache. Index is ink thickness,
0=no ink, 127=total coverage */
static int ColorCache[gdAlphaMax+1];
void CreateImage(pixels x_width,pixels y_width)
{
if (page_imagep)
gdImageDestroy(page_imagep);
if (x_width <= 0) x_width=1;
if (y_width <= 0) y_width=1;
#ifdef HAVE_GDIMAGECREATETRUECOLOR
/* GIFs are 256-color */
if ((option_flags & FORCE_TRUECOLOR
|| page_flags & PAGE_TRUECOLOR)
&& ~option_flags & GIF_OUTPUT
&& ~option_flags & FORCE_PALETTE)
page_imagep=gdImageCreateTrueColor(x_width,y_width);
else
#endif
page_imagep=gdImageCreate(x_width,y_width);
/* Set bg color. GIFs cannot handle an alpha channel, resort to
transparent color index, set in WriteImage */
if (!page_imagep)
Fatal("cannot allocate GD image for DVI");
ColorCache[0]
= gdImageColorAllocateAlpha(page_imagep,
cstack[0].red,
cstack[0].green,
cstack[0].blue,
(option_flags & BG_TRANSPARENT_ALPHA
&& ~option_flags & GIF_OUTPUT) ? 127 : 0);
ColorCache[gdAlphaMax]=-1;
#ifdef HAVE_GDIMAGECREATETRUECOLOR
/* Alpha blending in libgd is only performed for truecolor images.
We need it for palette images also. Turn libgd alpha blending off
and calculate color blending where needed. We turn it back on
briefly for image inclusion. */
gdImageAlphaBlending(page_imagep, 0);
if (option_flags & BG_TRANSPARENT_ALPHA)
gdImageSaveAlpha(page_imagep, 1);
if (page_imagep->trueColor)
/* Truecolor: there is no background color index, fill image instead. */
gdImageFilledRectangle(page_imagep, 0, 0,
x_width-1, y_width-1, ColorCache[0]);
#endif
}
static void ChangeColor(gdImagePtr imagep,int x1,int y1,
int x2,int y2,int color1,int color2)
/* In the given rectangle, change color1 to color2 */
{
int x,y;
for( y=y1; y<=y2; y++) {
for( x=x1; x<=x2; x++) {
if (gdImageGetPixel(imagep, x, y)==color1)
gdImageSetPixel(imagep, x, y, color2);
}
}
}
void WriteImage(char *pngname, int pagenum)
{
char* pos, *freeme=NULL;
FILE* outfp=NULL;
/* Set transparent background. Maybe alpha is not available or
perhaps we are producing GIFs, so test for BG_TRANSPARENT_ALPHA
too */
if (option_flags & (BG_TRANSPARENT|BG_TRANSPARENT_ALPHA))
gdImageColorTransparent(page_imagep,ColorCache[0]);
/* Transparent border */
if (borderwidth>0) {
int Transparent;
pixels x_width,y_width;
x_width=gdImageSX(page_imagep);
y_width=gdImageSY(page_imagep);
/* Set ANOTHER bg color, transparent this time */
/* No semi-transparency here, given the motivation for this code
* (box cursor visibility in Emacs) */
if (userbordercolor)
Transparent = gdImageColorAllocate(page_imagep,
bordercolor.red,
bordercolor.green,
bordercolor.blue);
else
Transparent = gdImageColorAllocate(page_imagep,
gdImageRed(page_imagep,ColorCache[0]),
gdImageGreen(page_imagep,ColorCache[0]),
gdImageBlue(page_imagep,ColorCache[0]));
gdImageColorTransparent(page_imagep,Transparent);
ChangeColor(page_imagep,0,0,x_width-1,borderwidth-1,
ColorCache[0],Transparent);
ChangeColor(page_imagep,0,0,borderwidth-1,y_width-1,
ColorCache[0],Transparent);
ChangeColor(page_imagep,x_width-borderwidth,0,x_width-1,y_width-1,
ColorCache[0],Transparent);
ChangeColor(page_imagep,0,y_width-borderwidth,x_width-1,y_width-1,
ColorCache[0],Transparent);
}
if ((pos=strchr(pngname,'%')) != NULL) {
if (strchr(++pos,'%'))
Fatal("too many %%s in output file name");
if (*pos == 'd'
|| (*pos=='0' && pos[1]>='1' && pos[1]<='9' && pos[2]=='d')) {
/* %d -> pagenumber, so add 9 string positions
since pagenumber max +-2^31 or +-2*10^9 */
if ((freeme = malloc(strlen(pngname)+9))==NULL)
Fatal("cannot allocate memory for output file name");
sprintf(freeme,pngname,pagenum);
pngname = freeme;
} else {
Fatal("unacceptable format spec in output file name");
}
}
#ifdef HAVE_GDIMAGEGIF
if (option_flags & GIF_OUTPUT && (pos=strrchr(pngname,'.')) != NULL
&& strcmp(pos,".png")==0) {
*(pos+1)='g';
*(pos+2)='i';
*(pos+3)='f';
}
#endif
if ((outfp = fopen(pngname,"wb")) == NULL)
Fatal("cannot open output file %s",pngname);
#ifdef HAVE_GDIMAGEGIF
if (option_flags & GIF_OUTPUT)
gdImageGif(page_imagep,outfp);
else
#endif
gdImagePngEx(page_imagep,outfp,compression);
fclose(outfp);
DEBUG_PRINT(DEBUG_DVI,("\n WROTE: \t%s\n",pngname));
if (freeme)
free(freeme);
DestroyImage();
}
void DestroyImage(void)
{
gdImageDestroy(page_imagep);
page_imagep=NULL;
}
static int gammatable[]=
{0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,
20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,
40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,
60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,
80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,
100,101,102,103,104,105,106,107,108,109,
110,111,112,113,114,115,116,117,118,119,
120,121,122,123,124,125,126,127};
void Gamma(double gamma)
{
int i=0;
while (i<=gdAlphaMax) {
gammatable[i]=gdAlphaMax-
(int)(pow((gdAlphaMax-i)/((double)gdAlphaMax),gamma)*gdAlphaMax);
DEBUG_PRINT(DEBUG_GLYPH,
("\n GAMMA GREYSCALE: %d -> %d ",i,gammatable[i]));
i++;
}
}
dviunits SetGlyph(struct char_entry *ptr, int32_t hh,int32_t vv)
/* gdImageChar can only do monochrome glyphs */
{
int dst_alpha,dst_weight,tot_weight,alpha;
int x,y,pos=0;
int bgColor,pixelgrey,pixelcolor;
hh -= ptr->xOffset/shrinkfactor;
vv -= ptr->yOffset/shrinkfactor;
/* Initialize persistent color cache. Perhaps this should be in
color.c? */
pixelcolor=gdImageColorResolve(page_imagep,
cstack[csp].red,
cstack[csp].green,
cstack[csp].blue);
if (ColorCache[gdAlphaMax]!=pixelcolor) {
for( x=1; x<gdAlphaMax; x++ )
ColorCache[x]=-1;
ColorCache[gdAlphaMax]=pixelcolor;
}
for( y=0; y<ptr->h; y++) {
for( x=0; x<ptr->w; x++) {
if (ptr->data[pos]>0) {
pixelgrey=gammatable[(int)ptr->data[pos]/2];
bgColor = gdImageGetPixel(page_imagep, hh + x, vv + y);
if (ColorCache[0]!=bgColor || ColorCache[pixelgrey]==-1) {
DEBUG_PRINT(DEBUG_GLYPH,("\n GAMMA GREYSCALE: %d -> %d ",
ptr->data[pos]/2,pixelgrey));
alpha = gdAlphaMax-pixelgrey;
dst_alpha = gdImageAlpha(page_imagep,bgColor);
dst_weight = (gdAlphaMax - dst_alpha) * alpha / gdAlphaMax;
tot_weight = pixelgrey + dst_weight;
pixelcolor = gdImageColorResolveAlpha(page_imagep,
(cstack[csp].red*pixelgrey
+ gdImageRed(page_imagep,bgColor)*dst_weight)/tot_weight,
(cstack[csp].green*pixelgrey
+ gdImageGreen(page_imagep,bgColor)*dst_weight)/tot_weight,
(cstack[csp].blue*pixelgrey
+ gdImageBlue(page_imagep,bgColor)*dst_weight)/tot_weight,
alpha*dst_alpha/gdAlphaMax);
if (ColorCache[0]==bgColor)
ColorCache[pixelgrey]=pixelcolor;
} else
pixelcolor=ColorCache[pixelgrey];
gdImageSetPixel(page_imagep, hh + x, vv + y, pixelcolor);
}
pos++;
}
}
return(ptr->tfmw);
}
dviunits SetRule(dviunits a, dviunits b, subpixels hh,subpixels vv)
{
/* This routine will draw a \rule */
int Color;
pixels width=0, height=0;
if ( a > 0 && b > 0 ) {
/* Calculate width and height, round up */
width = (b+dvi->conv*shrinkfactor-1)/dvi->conv/shrinkfactor;
height = (a+dvi->conv*shrinkfactor-1)/dvi->conv/shrinkfactor;
}
if (page_imagep != NULL) {
if ((height>0) && (width>0)) {
/* This code produces too dark rules. But what the hell. Grey
* rules look fuzzy. */
Color = gdImageColorResolve(page_imagep,
cstack[csp].red,
cstack[csp].green,
cstack[csp].blue);
/* +1 and -1 are because the Rectangle coords include last pixels */
gdImageFilledRectangle(page_imagep,hh,vv-height+1,hh+width-1,vv,Color);
DEBUG_PRINT(DEBUG_DVI,("\n RULE \t%dx%d at (%d,%d)",
width, height, hh, vv));
}
} else {
/* The +1's are because things are cut _at_that_coordinate_. */
min(x_min,hh);
min(y_min,vv-height+1);
max(x_max,hh+width);
max(y_max,vv+1);
}
return(b);
}