dockapps/wmglobe/src/mycontext.c

/* WMGlobe 0.5 -  All the Earth on a WMaker Icon
 * mycontext.c - an adaptation of wrlib for use in wmglobe
 * initial source taken in WindowMaker-0.20.3/wrlib :
 */
/* context.c - X context management
 *  Raster graphics library
 *
 *  Copyright (c) 1997 Alfredo K. Kojima
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 * #include <config.h>
 */
#include "wmglobe.h"

/*
 * #include <X11/Xlib.h>
 * #include <X11/Xutil.h>
 * #include <X11/Xatom.h>
 *
 * #include <stdio.h>
 * #include <stdlib.h>
 * #include <string.h>
 * #include <assert.h>
 *
 * #include <math.h>
 *
 * #include "wraster.h"
 */

static Bool bestContext(Display * dpy, int screen_number, RContext * context);

static RContextAttributes DEFAULT_CONTEXT_ATTRIBS =
{
	RC_DefaultVisual,	/* flags */
	0,			/* render_mode */
	0,			/* colors_per_channel */
	0,
	0,
	0,
	0,
	0			/* NO use_shared_memory */
};


static XColor *
 allocatePseudoColor(RContext * ctx)
{
	XColor *colors;
	XColor avcolors[256];
	int avncolors;
	int i, ncolors, r, g, b;
	int retries;
	int cpc = ctx->attribs->colors_per_channel;

	ncolors = cpc * cpc * cpc;

	if (ncolors > (1 << ctx->depth)) {
		/* reduce colormap size */
		cpc = ctx->attribs->colors_per_channel = 1 << ((int) ctx->depth / 3);
		ncolors = cpc * cpc * cpc;
	}
	assert(cpc >= 2 && ncolors <= (1 << ctx->depth));

	colors = malloc(sizeof(XColor) * ncolors);
	if (!colors) {
		RErrorCode = RERR_NOMEMORY;
		return NULL;
	}
	i = 0;

	if ((ctx->attribs->flags & RC_GammaCorrection) && ctx->attribs->rgamma > 0
	    && ctx->attribs->ggamma > 0 && ctx->attribs->bgamma > 0) {
		double rg, gg, bg;
		double tmp;

		/* do gamma correction */
		rg = 1.0 / ctx->attribs->rgamma;
		gg = 1.0 / ctx->attribs->ggamma;
		bg = 1.0 / ctx->attribs->bgamma;
		for (r = 0; r < cpc; r++) {
			for (g = 0; g < cpc; g++) {
				for (b = 0; b < cpc; b++) {
					colors[i].red = (r * 0xffff) / (cpc - 1);
					colors[i].green = (g * 0xffff) / (cpc - 1);
					colors[i].blue = (b * 0xffff) / (cpc - 1);
					colors[i].flags = DoRed | DoGreen | DoBlue;

					tmp = (double) colors[i].red / 65536.0;
					colors[i].red = (unsigned short) (65536.0 * pow(tmp, rg));

					tmp = (double) colors[i].green / 65536.0;
					colors[i].green = (unsigned short) (65536.0 * pow(tmp, gg));

					tmp = (double) colors[i].blue / 65536.0;
					colors[i].blue = (unsigned short) (65536.0 * pow(tmp, bg));

					i++;
				}
			}
		}

	} else {
		for (r = 0; r < cpc; r++) {
			for (g = 0; g < cpc; g++) {
				for (b = 0; b < cpc; b++) {
					colors[i].red = (r * 0xffff) / (cpc - 1);
					colors[i].green = (g * 0xffff) / (cpc - 1);
					colors[i].blue = (b * 0xffff) / (cpc - 1);
					colors[i].flags = DoRed | DoGreen | DoBlue;
					i++;
				}
			}
		}
	}
	/* try to allocate the colors */
	for (i = 0; i < ncolors; i++) {
		if (!XAllocColor(ctx->dpy, ctx->cmap, &(colors[i]))) {
			colors[i].flags = 0;	/* failed */
		} else {
			colors[i].flags = DoRed | DoGreen | DoBlue;
		}
	}
	/* try to allocate close values for the colors that couldn't
	 * be allocated before */
	avncolors = (1 << ctx->depth > 256 ? 256 : 1 << ctx->depth);
	for (i = 0; i < avncolors; i++)
		avcolors[i].pixel = i;

	XQueryColors(ctx->dpy, ctx->cmap, avcolors, avncolors);

	for (i = 0; i < ncolors; i++) {
		if (colors[i].flags == 0) {
			int j;
			unsigned long cdiff = 0xffffffff, diff;
			unsigned long closest = 0;

			retries = 2;

			while (retries--) {
				/* find closest color */
				for (j = 0; j < avncolors; j++) {
					r = (colors[i].red - avcolors[i].red) >> 8;
					g = (colors[i].green - avcolors[i].green) >> 8;
					b = (colors[i].blue - avcolors[i].blue) >> 8;
					diff = r * r + g * g + b * b;
					if (diff < cdiff) {
						cdiff = diff;
						closest = j;
					}
				}
				/* allocate closest color found */
				colors[i].red = avcolors[closest].red;
				colors[i].green = avcolors[closest].green;
				colors[i].blue = avcolors[closest].blue;
				if (XAllocColor(ctx->dpy, ctx->cmap, &colors[i])) {
					colors[i].flags = DoRed | DoGreen | DoBlue;
					break;	/* succeeded, don't need to retry */
				}
#ifdef DEBUG
				printf("close color allocation failed. Retrying...\n");
#endif
			}
		}
	}
	return colors;
}


static XColor *
 allocateGrayScale(RContext * ctx)
{
	XColor *colors;
	XColor avcolors[256];
	int avncolors;
	int i, ncolors, r, g, b;
	int retries;
	int cpc = ctx->attribs->colors_per_channel;

	ncolors = cpc * cpc * cpc;

	if (ctx->vclass == StaticGray) {
		/* we might as well use all grays */
		ncolors = 1 << ctx->depth;
	} else {
		if (ncolors > (1 << ctx->depth)) {
			/* reduce colormap size */
			cpc = ctx->attribs->colors_per_channel = 1 << ((int) ctx->depth / 3);
			ncolors = cpc * cpc * cpc;
		}
		assert(cpc >= 2 && ncolors <= (1 << ctx->depth));
	}

	if (ncolors >= 256 && ctx->vclass == StaticGray) {
		/* don't need dithering for 256 levels of gray in StaticGray visual */
		ctx->attribs->render_mode = RM_MATCH;
	}
	colors = malloc(sizeof(XColor) * ncolors);
	if (!colors) {
		RErrorCode = RERR_NOMEMORY;
		return False;
	}
	for (i = 0; i < ncolors; i++) {
		colors[i].red = (i * 0xffff) / (ncolors - 1);
		colors[i].green = (i * 0xffff) / (ncolors - 1);
		colors[i].blue = (i * 0xffff) / (ncolors - 1);
		colors[i].flags = DoRed | DoGreen | DoBlue;
	}
	/* try to allocate the colors */
	for (i = 0; i < ncolors; i++) {
#ifdef DEBUG
		printf("trying:%x,%x,%x\n", colors[i].red, colors[i].green, colors[i].blue);
#endif
		if (!XAllocColor(ctx->dpy, ctx->cmap, &(colors[i]))) {
			colors[i].flags = 0;	/* failed */
#ifdef DEBUG
			printf("failed:%x,%x,%x\n", colors[i].red, colors[i].green, colors[i].blue);
#endif
		} else {
			colors[i].flags = DoRed | DoGreen | DoBlue;
#ifdef DEBUG
			printf("success:%x,%x,%x\n", colors[i].red, colors[i].green, colors[i].blue);
#endif
		}
	}
	/* try to allocate close values for the colors that couldn't
	 * be allocated before */
	avncolors = (1 << ctx->depth > 256 ? 256 : 1 << ctx->depth);
	for (i = 0; i < avncolors; i++)
		avcolors[i].pixel = i;

	XQueryColors(ctx->dpy, ctx->cmap, avcolors, avncolors);

	for (i = 0; i < ncolors; i++) {
		if (colors[i].flags == 0) {
			int j;
			unsigned long cdiff = 0xffffffff, diff;
			unsigned long closest = 0;

			retries = 2;

			while (retries--) {
				/* find closest color */
				for (j = 0; j < avncolors; j++) {
					r = (colors[i].red - avcolors[i].red) >> 8;
					g = (colors[i].green - avcolors[i].green) >> 8;
					b = (colors[i].blue - avcolors[i].blue) >> 8;
					diff = r * r + g * g + b * b;
					if (diff < cdiff) {
						cdiff = diff;
						closest = j;
					}
				}
				/* allocate closest color found */
#ifdef DEBUG
				printf("best match:%x,%x,%x => %x,%x,%x\n", colors[i].red, colors[i].green, colors[i].blue, avcolors[closest].red, avcolors[closest].green, avcolors[closest].blue);
#endif
				colors[i].red = avcolors[closest].red;
				colors[i].green = avcolors[closest].green;
				colors[i].blue = avcolors[closest].blue;
				if (XAllocColor(ctx->dpy, ctx->cmap, &colors[i])) {
					colors[i].flags = DoRed | DoGreen | DoBlue;
					break;	/* succeeded, don't need to retry */
				}
#ifdef DEBUG
				printf("close color allocation failed. Retrying...\n");
#endif
			}
		}
	}
	return colors;
}


static char *
 mygetenv(char *var, int scr)
{
	char *p;
	char varname[64];

	sprintf(varname, "%s%i", var, scr);
	p = getenv(varname);
	if (!p) {
		p = getenv(var);
	}
	return p;
}


static void gatherconfig(RContext * context, int screen_n)
{
	char *ptr;

	ptr = mygetenv("WRASTER_GAMMA", screen_n);
	if (ptr) {
		float g1, g2, g3;
		if (sscanf(ptr, "%f/%f/%f", &g1, &g2, &g3) != 3
		    || g1 <= 0.0 || g2 <= 0.0 || g3 <= 0.0) {
			printf("wrlib: invalid value(s) for gamma correction \"%s\"\n",
			       ptr);
		} else {
			context->attribs->flags |= RC_GammaCorrection;
			context->attribs->rgamma = g1;
			context->attribs->ggamma = g2;
			context->attribs->bgamma = g3;
		}
	}
	ptr = mygetenv("WRASTER_COLOR_RESOLUTION", screen_n);
	if (ptr) {
		int i;
		if (sscanf(ptr, "%d", &i) != 1 || i < 2 || i > 6) {
			printf("wrlib: invalid value for color resolution \"%s\"\n", ptr);
		} else {
			context->attribs->flags |= RC_ColorsPerChannel;
			context->attribs->colors_per_channel = i;
		}
	}
}


static void getColormap(RContext * context, int screen_number)
{
	Colormap cmap = None;
	XStandardColormap *cmaps;
	int ncmaps, i;

	if (XGetRGBColormaps(context->dpy,
			     RootWindow(context->dpy, screen_number),
			     &cmaps, &ncmaps, XA_RGB_DEFAULT_MAP)) {
		for (i = 0; i < ncmaps; ++i) {
			if (cmaps[i].visualid == context->visual->visualid) {
				puts("ACHOU");
				cmap = cmaps[i].colormap;
				break;
			}
		}
		XFree(cmaps);
	}
	if (cmap == None) {
		XColor color;

		cmap = XCreateColormap(context->dpy,
				 RootWindow(context->dpy, screen_number),
				       context->visual, AllocNone);

		color.red = color.green = color.blue = 0;
		XAllocColor(context->dpy, cmap, &color);
		context->black = color.pixel;

		color.red = color.green = color.blue = 0xffff;
		XAllocColor(context->dpy, cmap, &color);
		context->white = color.pixel;

	}
	context->cmap = cmap;
}


static int count_offset(unsigned long mask)
{
	int i;

	i = 0;
	while ((mask & 1) == 0) {
		i++;
		mask = mask >> 1;
	}
	return i;
}


RContext *
 myRCreateContext(Display * dpy, int screen_number, RContextAttributes * attribs)
{
	RContext *context;
	XGCValues gcv;


	context = malloc(sizeof(RContext));
	if (!context) {
		RErrorCode = RERR_NOMEMORY;
		return NULL;
	}
	memset(context, 0, sizeof(RContext));

	context->dpy = dpy;

	context->screen_number = screen_number;

	context->attribs = malloc(sizeof(RContextAttributes));
	if (!context->attribs) {
		free(context);
		RErrorCode = RERR_NOMEMORY;
		return NULL;
	}
	if (!attribs)
		*context->attribs = DEFAULT_CONTEXT_ATTRIBS;
	else
		*context->attribs = *attribs;

	/* get configuration from environment variables */
	gatherconfig(context, screen_number);

	if ((context->attribs->flags & RC_VisualID)) {
		XVisualInfo *vinfo, templ;
		int nret;

		templ.screen = screen_number;
		templ.visualid = context->attribs->visualid;
		vinfo = XGetVisualInfo(context->dpy, VisualIDMask | VisualScreenMask,
				       &templ, &nret);
		if (!vinfo || nret == 0) {
			free(context);
			RErrorCode = RERR_BADVISUALID;
			return NULL;
		}
		if (vinfo[0].visual == DefaultVisual(dpy, screen_number)) {
			context->attribs->flags |= RC_DefaultVisual;
		} else {
			XSetWindowAttributes attr;
			unsigned long mask;

			context->visual = vinfo[0].visual;
			context->depth = vinfo[0].depth;
			context->vclass = vinfo[0].class;
			getColormap(context, screen_number);
			attr.colormap = context->cmap;
			attr.override_redirect = True;
			attr.border_pixel = 0;
			attr.background_pixel = 0;
			mask = CWBorderPixel | CWColormap | CWOverrideRedirect | CWBackPixel;
			context->drawable =
			    XCreateWindow(dpy, RootWindow(dpy, screen_number), 1, 1,
				 1, 1, 0, context->depth, CopyFromParent,
					  context->visual, mask, &attr);
			/*          XSetWindowColormap(dpy, context->drawable, attr.colormap); */
		}
		XFree(vinfo);
	}
	/* use default */
	if (!context->visual) {
		if ((context->attribs->flags & RC_DefaultVisual)
		    || !bestContext(dpy, screen_number, context)) {
			context->visual = DefaultVisual(dpy, screen_number);
			context->depth = DefaultDepth(dpy, screen_number);
			context->cmap = DefaultColormap(dpy, screen_number);
			context->drawable = RootWindow(dpy, screen_number);
			context->black = BlackPixel(dpy, screen_number);
			context->white = WhitePixel(dpy, screen_number);
			context->vclass = context->visual->class;
		}
	}
	gcv.function = GXcopy;
	gcv.graphics_exposures = False;
	context->copy_gc = XCreateGC(dpy, context->drawable, GCFunction
				     | GCGraphicsExposures, &gcv);

	if (context->vclass == PseudoColor || context->vclass == StaticColor) {
		context->colors = allocatePseudoColor(context);
		if (!context->colors) {
			return NULL;
		}
	} else if (context->vclass == GrayScale || context->vclass == StaticGray) {
		context->colors = allocateGrayScale(context);
		if (!context->colors) {
			return NULL;
		}
	} else if (context->vclass == TrueColor) {
		/* calc offsets to create a TrueColor pixel */
		context->red_offset = count_offset(context->visual->red_mask);
		context->green_offset = count_offset(context->visual->green_mask);
		context->blue_offset = count_offset(context->visual->blue_mask);
		/* disable dithering on 24 bits visuals */
		if (context->depth >= 24)
			context->attribs->render_mode = RM_MATCH;
	}
	/* check avaiability of MIT-SHM */

	return context;
}


static Bool
 bestContext(Display * dpy, int screen_number, RContext * context)
{
	XVisualInfo *vinfo = NULL, rvinfo;
	int best = -1, numvis, i;
	long flags;
	XSetWindowAttributes attr;

	rvinfo.class = TrueColor;
	rvinfo.screen = screen_number;
	flags = VisualClassMask | VisualScreenMask;

	vinfo = XGetVisualInfo(dpy, flags, &rvinfo, &numvis);
	if (vinfo) {		/* look for a TrueColor, 24-bit or more (pref 24) */
		for (i = numvis - 1, best = -1; i >= 0; i--) {
			if (vinfo[i].depth == 24)
				best = i;
			else if (vinfo[i].depth > 24 && best < 0)
				best = i;
		}
	}
#if 0
	if (best == -1) {	/* look for a DirectColor, 24-bit or more (pref 24) */
		rvinfo.class = DirectColor;
		if (vinfo)
			XFree((char *) vinfo);
		vinfo = XGetVisualInfo(dpy, flags, &rvinfo, &numvis);
		if (vinfo) {
			for (i = 0, best = -1; i < numvis; i++) {
				if (vinfo[i].depth == 24)
					best = i;
				else if (vinfo[i].depth > 24 && best < 0)
					best = i;
			}
		}
	}
#endif
	if (best > -1) {
		context->visual = vinfo[best].visual;
		context->depth = vinfo[best].depth;
		context->vclass = vinfo[best].class;
		getColormap(context, screen_number);
		attr.colormap = context->cmap;
		attr.override_redirect = True;
		attr.border_pixel = 0;
		context->drawable =
		    XCreateWindow(dpy, RootWindow(dpy, screen_number),
				  1, 1, 1, 1, 0, context->depth,
				  CopyFromParent, context->visual,
		 CWBorderPixel | CWColormap | CWOverrideRedirect, &attr);
/*      XSetWindowColormap(dpy, context->drawable, context->cmap); */
	}
	if (vinfo)
		XFree((char *) vinfo);

	if (best < 0)
		return False;
	else
		return True;
}