From e88d645e01f3bfbdbeb965f49a091887ead04ab1 Mon Sep 17 00:00:00 2001
From: Nickolay V. Shmyrev <nshmyrev@src.gnome.org>
Date: Sat, 09 Apr 2005 19:30:47 +0000
Subject: Dvi thumbnails and improved antialiasing of dvi rules. Fix compilation

warnings.
---
(limited to 'dvi/mdvi-lib/color.c')

diff --git a/dvi/mdvi-lib/color.c b/dvi/mdvi-lib/color.c
new file mode 100644
index 0000000..ae63a87
--- /dev/null
+++ b/dvi/mdvi-lib/color.c
@@ -0,0 +1,135 @@
+/*
+ * Copyright (C) 2000, Matias Atria
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "mdvi.h"
+#include "color.h"
+
+void	mdvi_set_color(DviContext *dvi, Ulong fg, Ulong bg)
+{
+	if(dvi->curr_fg != fg || dvi->curr_bg != bg) {
+		DEBUG((DBG_DEVICE, "setting color to (%lu,%lu)\n", fg, bg));
+		if(dvi->device.set_color)
+			dvi->device.set_color(dvi->device.device_data, fg, bg);
+		dvi->curr_fg = fg;
+		dvi->curr_bg = bg;
+	}
+}
+
+void	mdvi_push_color(DviContext *dvi, Ulong fg, Ulong bg)
+{
+	if(dvi->color_top == dvi->color_size) {
+		dvi->color_size += 32;
+		dvi->color_stack = xrealloc(dvi->color_stack,
+			dvi->color_size * sizeof(DviColorPair));
+	}
+	dvi->color_stack[dvi->color_top].fg = dvi->curr_fg;
+	dvi->color_stack[dvi->color_top].bg = dvi->curr_bg;
+	dvi->color_top++;
+	mdvi_set_color(dvi, fg, bg);
+}
+
+void	mdvi_pop_color(DviContext *dvi)
+{
+	Ulong	fg, bg;
+	
+	if(dvi->color_top == 0)
+		return;
+	dvi->color_top--;
+	fg = dvi->color_stack[dvi->color_top].fg;
+	bg = dvi->color_stack[dvi->color_top].bg;
+	mdvi_set_color(dvi, fg, bg);
+}
+
+void	mdvi_reset_color(DviContext *dvi)
+{
+	dvi->color_top = 0;
+	mdvi_set_color(dvi, dvi->params.fg, dvi->params.bg);
+}
+
+/* cache for color tables, to avoid creating them for every glyph */
+typedef struct {
+	Ulong	fg;
+	Ulong	bg;
+	Uint	nlevels;
+	Ulong	*pixels;
+	int	density;
+	double	gamma;
+	Uint	hits;
+} ColorCache;
+
+#define CCSIZE		256
+static ColorCache	color_cache[CCSIZE];
+static int		cc_entries;
+
+#define GAMMA_DIFF	0.005
+
+
+/* create a color table */
+Ulong	*get_color_table(DviDevice *dev, 
+			 int nlevels, Ulong fg, Ulong bg, double gamma, int density)
+{
+	ColorCache	*cc, *tofree;
+	int		lohits;
+	Ulong		*pixels;
+	int		status;
+
+	lohits = color_cache[0].hits;
+	tofree = &color_cache[0];
+	/* look in the cache and see if we have one that matches this request */
+	for(cc = &color_cache[0]; cc < &color_cache[cc_entries]; cc++) {
+		if(cc->hits < lohits) {
+			lohits = cc->hits;
+			tofree = cc;
+		}
+		if(cc->fg == fg && cc->bg == bg && cc->density == density &&
+		   cc->nlevels == nlevels && fabs(cc->gamma - gamma) <= GAMMA_DIFF)
+		   	break;
+	}
+
+	if(cc < &color_cache[cc_entries]) {
+		cc->hits++;
+		return cc->pixels;
+	}
+
+	DEBUG((DBG_DEVICE, "Adding color table to cache (fg=%lu, bg=%lu, n=%d)\n",
+		fg, bg, nlevels));
+		
+	/* no entry was found in the cache, create a new one */
+	if(cc_entries < CCSIZE) {
+		cc = &color_cache[cc_entries++];
+		cc->pixels = NULL;
+	} else {
+		cc = tofree;
+		xfree(cc->pixels);
+	}
+	pixels = xnalloc(Ulong, nlevels);
+	status = dev->alloc_colors(dev->device_data, 
+		pixels, nlevels, fg, bg, gamma, density);
+	if(status < 0) {
+		xfree(pixels);
+		return NULL;
+	}
+	cc->fg = fg;
+	cc->bg = bg;
+	cc->gamma = gamma;
+	cc->density = density;
+	cc->nlevels = nlevels;
+	cc->pixels = pixels;
+	cc->hits = 1;
+	return pixels;	
+}
--
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