ocaml/otherlibs/graph/color.c

231 lines
6.2 KiB
C

/***********************************************************************/
/* */
/* Objective Caml */
/* */
/* Xavier Leroy, projet Cristal, INRIA Rocquencourt */
/* */
/* Copyright 1996 Institut National de Recherche en Informatique et */
/* en Automatique. All rights reserved. This file is distributed */
/* under the terms of the GNU Library General Public License, with */
/* the special exception on linking described in file ../../LICENSE. */
/* */
/***********************************************************************/
/* $Id$ */
#include "libgraph.h"
#include <X11/Xatom.h>
/* Cache to speed up the translation rgb -> pixel value. */
struct color_cache_entry {
int rgb; /* RGB value with format 0xRRGGBB */
unsigned long pixel; /* Pixel value */
};
#define Color_cache_size 512
static struct color_cache_entry color_cache[Color_cache_size];
#define Empty (-1)
#define Hash_rgb(r,g,b) \
((((r) & 0xE0) << 1) + (((g) & 0xE0) >> 2) + (((b) & 0xE0) >> 5))
#define Color_cache_slack 16
static int num_overflows = 0;
/* rgb -> pixel conversion *without* display connection */
Bool direct_rgb = False;
int red_l, red_r;
int green_l, green_r;
int blue_l, blue_r;
unsigned long red_mask, green_mask, blue_mask;
/* rgb -> pixel table */
unsigned long red_vals[256];
unsigned long green_vals[256];
unsigned long blue_vals[256];
void get_shifts( unsigned long mask, int *lsl, int *lsr )
{
int l = 0;
int r = 0;
int bit = 1;
if ( mask == 0 ){ *lsl = -1; *lsr = -1; return; }
for( l = 0; l < 32; l++ ){
if( bit & mask ){ break; }
bit = bit << 1;
}
for( r = l; r < 32; r++ ){
if( ! (bit & mask) ){ break; }
bit = bit << 1;
}
/* fix r */
if ( r == 32 ) { r = 31; }
*lsl = l;
*lsr = 16 - (r - l);
}
void gr_init_direct_rgb_to_pixel(void)
{
Visual *visual;
int i;
visual = DefaultVisual(grdisplay,grscreen);
if ( visual->class == TrueColor || visual->class == DirectColor ){
int lsl, lsr;
red_mask = visual->red_mask;
green_mask = visual->green_mask;
blue_mask = visual->blue_mask;
#ifdef QUICKCOLORDEBUG
fprintf(stderr, "visual %lx %lx %lx\n",
red_mask,
green_mask,
blue_mask);
#endif
get_shifts(red_mask, &red_l, &red_r);
#ifdef QUICKCOLORDEBUG
fprintf(stderr, "red %d %d\n", red_l, red_r);
#endif
for(i=0; i<256; i++){
red_vals[i] = (((i << 8) + i) >> red_r) << red_l;
}
get_shifts(green_mask, &green_l, &green_r);
#ifdef QUICKCOLORDEBUG
fprintf(stderr, "green %d %d\n", green_l, green_r);
#endif
for(i=0; i<256; i++){
green_vals[i] = (((i << 8) + i) >> green_r) << green_l;
}
get_shifts(blue_mask, &blue_l, &blue_r);
#ifdef QUICKCOLORDEBUG
fprintf(stderr, "blue %d %d\n", blue_l, blue_r);
#endif
for(i=0; i<256; i++){
blue_vals[i] = (((i << 8) + i) >> blue_r) << blue_l;
}
if( red_l < 0 || red_r < 0 ||
green_l < 0 || green_r < 0 ||
blue_l < 0 || blue_r < 0 ){
#ifdef QUICKCOLORDEBUG
fprintf(stderr, "Damn, boost failed\n");
#endif
direct_rgb = False;
} else {
#ifdef QUICKCOLORDEBUG
fprintf(stderr, "Boost ok\n");
#endif
direct_rgb = True;
}
} else {
/* we cannot use direct_rgb_to_pixel */
#ifdef QUICKCOLORDEBUG
fprintf(stderr, "No boost!\n");
#endif
direct_rgb = False;
}
}
void gr_init_color_cache(void)
{
int i;
for (i = 0; i < Color_cache_size; i++) color_cache[i].rgb = Empty;
i = Hash_rgb(0, 0, 0);
color_cache[i].rgb = 0;
color_cache[i].pixel = grblack;
i = Hash_rgb(0xFF, 0xFF, 0xFF);
color_cache[i].rgb = 0xFFFFFF;
color_cache[i].pixel = grwhite;
}
unsigned long gr_pixel_rgb(int rgb)
{
unsigned int r, g, b;
int h, i;
XColor color;
unsigned short tmp;
r = (rgb >> 16) & 0xFF;
g = (rgb >> 8) & 0xFF;
b = rgb & 0xFF;
if (direct_rgb){
return red_vals[r] | green_vals[g] | blue_vals[b];
}
h = Hash_rgb(r, g, b);
i = h;
while(1) {
if (color_cache[i].rgb == Empty) break;
if (color_cache[i].rgb == rgb) return color_cache[i].pixel;
i = (i + 1) & (Color_cache_size - 1);
if (i == h) {
/* Cache is full. Instead of inserting at slot h, which causes
thrashing if many colors hash to the same value,
insert at h + n where n is pseudo-random and
smaller than Color_cache_slack */
int slack = num_overflows++ & (Color_cache_slack - 1);
i = (i + slack) & (Color_cache_size - 1);
break;
}
}
color.red = r * 0x101;
color.green = g * 0x101;
color.blue = b * 0x101;
XAllocColor(grdisplay, grcolormap, &color);
color_cache[i].rgb = rgb;
color_cache[i].pixel = color.pixel;
return color.pixel;
}
int gr_rgb_pixel(long unsigned int pixel)
{
register int r,g,b;
XColor color;
int i;
if (direct_rgb) {
r = (((pixel & red_mask) >> red_l) << 8) >> (16 - red_r);
g = (((pixel & green_mask) >> green_l) << 8) >> (16 - green_r);
b = (((pixel & blue_mask) >> blue_l) << 8) >> (16 - blue_r);
return (r << 16) + (g << 8) + b;
}
if (pixel == grblack) return 0;
if (pixel == grwhite) return 0xFFFFFF;
/* Probably faster to do a linear search than to query the X server. */
for (i = 0; i < Color_cache_size; i++) {
if (color_cache[i].rgb != Empty && color_cache[i].pixel == pixel)
return color_cache[i].rgb;
}
color.pixel = pixel;
XQueryColor(grdisplay, grcolormap, &color);
return
((color.red >> 8) << 16) + ((color.green >> 8) << 8) + (color.blue >> 8);
}
value gr_set_color(value vrgb)
{
int xcolor;
gr_check_open();
grcolor = Int_val(vrgb);
if (grcolor >= 0 ){
xcolor = gr_pixel_rgb(Int_val(vrgb));
XSetForeground(grdisplay, grwindow.gc, xcolor);
XSetForeground(grdisplay, grbstore.gc, xcolor);
} else {
XSetForeground(grdisplay, grwindow.gc, grbackground);
XSetForeground(grdisplay, grbstore.gc, grbackground);
}
return Val_unit;
}