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Diffstat (limited to 'utils/visual.c')
| -rw-r--r-- | utils/visual.c | 555 |
1 files changed, 555 insertions, 0 deletions
diff --git a/utils/visual.c b/utils/visual.c new file mode 100644 index 0000000..c6764ba --- /dev/null +++ b/utils/visual.c @@ -0,0 +1,555 @@ +/* xscreensaver, Copyright (c) 1993-2017 by Jamie Zawinski <jwz@jwz.org> + * + * Permission to use, copy, modify, distribute, and sell this software and its + * documentation for any purpose is hereby granted without fee, provided that + * the above copyright notice appear in all copies and that both that + * copyright notice and this permission notice appear in supporting + * documentation. No representations are made about the suitability of this + * software for any purpose. It is provided "as is" without express or + * implied warranty. + */ + +/* This file contains some code for intelligently picking the best visual + (where "best" is biased in the direction of either: high color counts; + or: having writable color cells...) + */ + +#include "utils.h" +#include "resources.h" /* for get_string_resource() */ +#include "visual.h" + +#include <string.h> +#ifndef HAVE_ANDROID +#include <X11/Xutil.h> +#else +#include "../android/android-visual.h" +#endif + +extern char *progname; + +#ifndef isupper +# define isupper(c) ((c) >= 'A' && (c) <= 'Z') +#endif +#ifndef _tolower +# define _tolower(c) ((c) - 'A' + 'a') +#endif + + +static Visual *pick_best_visual (Screen *, Bool, Bool); +static Visual *pick_mono_visual (Screen *); +static Visual *pick_best_visual_of_class (Screen *, int); +static Visual *pick_best_gl_visual (Screen *); + + +#define DEFAULT_VISUAL -1 +#define BEST_VISUAL -2 +#define MONO_VISUAL -3 +#define GRAY_VISUAL -4 +#define COLOR_VISUAL -5 +#define GL_VISUAL -6 +#define SPECIFIC_VISUAL -7 + +Visual * +get_visual (Screen *screen, const char *string, Bool prefer_writable_cells, + Bool verbose_p) +{ + char *v = (string ? strdup(string) : 0); + char c, *tmp; + int vclass; + unsigned long id; + Visual *result = 0; + + if (v) + for (tmp = v; *tmp; tmp++) + if (isupper (*tmp)) *tmp = _tolower (*tmp); + + if (!v || !*v) vclass = BEST_VISUAL; + else if (!strcmp (v, "default")) vclass = DEFAULT_VISUAL; + else if (!strcmp (v, "best")) vclass = BEST_VISUAL; + else if (!strcmp (v, "mono")) vclass = MONO_VISUAL; + else if (!strcmp (v, "monochrome")) vclass = MONO_VISUAL; + else if (!strcmp (v, "gray")) vclass = GRAY_VISUAL; + else if (!strcmp (v, "grey")) vclass = GRAY_VISUAL; + else if (!strcmp (v, "color")) vclass = COLOR_VISUAL; + else if (!strcmp (v, "gl")) vclass = GL_VISUAL; + else if (!strcmp (v, "staticgray")) vclass = StaticGray; + else if (!strcmp (v, "staticcolor")) vclass = StaticColor; + else if (!strcmp (v, "truecolor")) vclass = TrueColor; + else if (!strcmp (v, "grayscale")) vclass = GrayScale; + else if (!strcmp (v, "greyscale")) vclass = GrayScale; + else if (!strcmp (v, "pseudocolor")) vclass = PseudoColor; + else if (!strcmp (v, "directcolor")) vclass = DirectColor; + else if (1 == sscanf (v, " %lu %c", &id, &c)) vclass = SPECIFIC_VISUAL; + else if (1 == sscanf (v, " 0x%lx %c", &id, &c)) vclass = SPECIFIC_VISUAL; + else + { + fprintf (stderr, "%s: unrecognized visual \"%s\".\n", progname, v); + vclass = DEFAULT_VISUAL; + } + + if (vclass == DEFAULT_VISUAL) + result = DefaultVisualOfScreen (screen); + else if (vclass == BEST_VISUAL) + result = pick_best_visual (screen, prefer_writable_cells, False); + else if (vclass == MONO_VISUAL) + { + result = pick_mono_visual (screen); + if (!result && verbose_p) + fprintf (stderr, "%s: no monochrome visuals.\n", progname); + } + else if (vclass == GRAY_VISUAL) + { + if (prefer_writable_cells) + result = pick_best_visual_of_class (screen, GrayScale); + if (!result) + result = pick_best_visual_of_class (screen, StaticGray); + if (!result) + result = pick_best_visual_of_class (screen, GrayScale); + if (!result && verbose_p) + fprintf (stderr, "%s: no GrayScale or StaticGray visuals.\n", + progname); + } + else if (vclass == COLOR_VISUAL) + { + int class; + /* First see if the default visual will do. */ + result = DefaultVisualOfScreen (screen); + class = visual_class(screen, result); + if (class != TrueColor && + class != PseudoColor && + class != DirectColor && + class != StaticColor) + result = 0; + if (result && visual_depth(screen, result) <= 1) + result = 0; + + /* Else, find the best non-default color visual */ + if (!result) + result = pick_best_visual (screen, prefer_writable_cells, True); + + if (!result && verbose_p) + fprintf (stderr, "%s: no color visuals.\n", progname); + } + else if (vclass == GL_VISUAL) + { + Visual *visual = pick_best_gl_visual (screen); + if (visual) + result = visual; + else if (verbose_p) + fprintf (stderr, "%s: no visual suitable for GL.\n", progname); + } + else if (vclass == SPECIFIC_VISUAL) + { + result = id_to_visual (screen, id); + if (!result && verbose_p) + fprintf (stderr, "%s: no visual with id 0x%x.\n", progname, + (unsigned int) id); + } + else + { + Visual *visual = pick_best_visual_of_class (screen, vclass); + if (visual) + result = visual; + else if (verbose_p) + fprintf (stderr, "%s: no visual of class %s.\n", progname, v); + } + + if (v) free (v); + return result; +} + +Visual * +get_visual_resource (Screen *screen, char *name, char *class, + Bool prefer_writable_cells) +{ + char *string = get_string_resource (DisplayOfScreen (screen), name, class); + Visual *v = get_visual (screen, string, prefer_writable_cells, True); + if (string) + free(string); + if (v) + return v; + else + return DefaultVisualOfScreen (screen); +} + + +static Visual * +pick_best_visual (Screen *screen, Bool prefer_writable_cells, Bool color_only) +{ + Visual *visual; + + if (!prefer_writable_cells) + { + /* If we don't prefer writable cells, then the "best" visual is the one + on which we can allocate the largest range and number of colors. + + Therefore, a TrueColor visual which is at least 16 bits deep is best. + (The assumption here being that a TrueColor of less than 16 bits is + really just a PseudoColor visual with a pre-allocated color cube.) + + The next best thing is a PseudoColor visual of any type. After that + come the non-colormappable visuals, and non-color visuals. + */ + if ((visual = pick_best_visual_of_class (screen, TrueColor)) && + visual_depth (screen, visual) >= 16) + return visual; + } + +#define TRY_CLASS(CLASS) \ + if ((visual = pick_best_visual_of_class (screen, CLASS)) && \ + (!color_only || visual_depth(screen, visual) > 1)) \ + return visual + TRY_CLASS(PseudoColor); + TRY_CLASS(TrueColor); + TRY_CLASS(DirectColor); + TRY_CLASS(StaticColor); + if (!color_only) + { + TRY_CLASS(GrayScale); + TRY_CLASS(StaticGray); + } +#undef TRY_CLASS + + visual = DefaultVisualOfScreen (screen); + if (!color_only || visual_depth(screen, visual) > 1) + return visual; + else + return 0; +} + +static Visual * +pick_mono_visual (Screen *screen) +{ + Display *dpy = DisplayOfScreen (screen); + XVisualInfo vi_in, *vi_out; + int out_count; + + vi_in.depth = 1; + vi_in.screen = screen_number (screen); + vi_out = XGetVisualInfo (dpy, (VisualDepthMask | VisualScreenMask), + &vi_in, &out_count); + if (vi_out) + { + Visual *v = (out_count > 0 ? vi_out [0].visual : 0); + if (v && vi_out[0].depth != 1) + v = 0; + XFree ((char *) vi_out); + return v; + } + else + return 0; +} + + +static Visual * +pick_best_visual_of_class (Screen *screen, int visual_class) +{ + /* The best visual of a class is the one which on which we can allocate + the largest range and number of colors, which means the one with the + greatest depth and number of cells. + + (But actually, for XDaliClock, all visuals of the same class are + probably equivalent - either we have writable cells or we don't.) + */ + Display *dpy = DisplayOfScreen (screen); + XVisualInfo vi_in, *vi_out; + int out_count; + + vi_in.class = visual_class; + vi_in.screen = screen_number (screen); + vi_out = XGetVisualInfo (dpy, (VisualClassMask | VisualScreenMask), + &vi_in, &out_count); + if (vi_out) + { + /* choose the 'best' one, if multiple */ + int i, best; + Visual *visual; +/* for (i = 0, best = 0; i < out_count; i++) */ + for (i = out_count-1, best = i; i >= 0; i--) /* go backwards */ + /* It's better if it's deeper, or if it's the same depth with + more cells (does that ever happen? Well, it could...) */ + if ((vi_out [i].depth > vi_out [best].depth) || + ((vi_out [i].depth == vi_out [best].depth) && + (vi_out [i].colormap_size > vi_out [best].colormap_size))) + best = i; + visual = (best < out_count ? vi_out [best].visual : 0); + XFree ((char *) vi_out); + return visual; + } + else + return 0; +} + +static Visual * +pick_best_gl_visual (Screen *screen) +{ + /* The best visual for GL is a TrueColor visual that is half as deep as + the screen. If such a thing doesn't exist, then TrueColor is best. + Failing that, the deepest available color visual is best. + + Compare this function to get_gl_visual() in visual-gl.c. + This function tries to find the best GL visual using Xlib calls, + whereas that function does the same thing using GLX calls. + */ + Display *dpy = DisplayOfScreen (screen); + XVisualInfo vi_in, *vi_out; + int out_count; + Visual *result = 0; + + int ndepths = 0; + int *depths = XListDepths (dpy, screen_number (screen), &ndepths); + int screen_depth = (depths && ndepths) ? depths[ndepths - 1] : 0; + XFree (depths); + + vi_in.class = TrueColor; + vi_in.screen = screen_number (screen); + vi_in.depth = screen_depth / 2; + vi_out = XGetVisualInfo (dpy, (VisualClassMask | VisualScreenMask | + VisualDepthMask), + &vi_in, &out_count); + if (out_count > 0) + result = vi_out[0].visual; + + if (vi_out) + XFree ((char *) vi_out); + + if (!result && screen_depth > 24) + { + /* If it's a 32-deep screen and we didn't find a depth-16 visual, + see if there's a depth-12 visual. */ + vi_in.class = TrueColor; + vi_in.screen = screen_number (screen); + vi_in.depth = 12; + vi_out = XGetVisualInfo (dpy, (VisualClassMask | VisualScreenMask | + VisualDepthMask), + &vi_in, &out_count); + if (out_count > 0) + result = vi_out[0].visual; + } + + if (!result) + /* No half-depth TrueColor? Ok, try for any TrueColor (the deepest.) */ + result = pick_best_visual_of_class (screen, TrueColor); + + if (!result) + /* No TrueColor? Ok, try for anything. */ + result = pick_best_visual (screen, False, False); + + return result; +} + + +static XVisualInfo * +visual_info_id (Screen *screen, int id) +{ + Display *dpy = DisplayOfScreen (screen); + XVisualInfo vi_in; + int out_count; + vi_in.screen = screen_number (screen); + vi_in.visualid = id; + return XGetVisualInfo (dpy, VisualScreenMask | VisualIDMask, + &vi_in, &out_count); +} + +static XVisualInfo * +visual_info (Screen *screen, Visual *visual) +{ + XVisualInfo *vi_out = visual_info_id (screen, XVisualIDFromVisual (visual)); + if (! vi_out) abort (); + return vi_out; +} + +Visual * +id_to_visual (Screen *screen, int id) +{ + XVisualInfo *vi_out = visual_info_id (screen, id); + if (vi_out) + { + Visual *v = vi_out[0].visual; + XFree ((char *) vi_out); + return v; + } + return 0; +} + +int +visual_depth (Screen *screen, Visual *visual) +{ + XVisualInfo *vi_out = visual_info (screen, visual); + int d = vi_out [0].depth; + XFree ((char *) vi_out); + return d; +} + + +/* You very probably don't want to be using this. + Pixmap depth doesn't refer to the depths of pixmaps, but rather, to + the depth of protocol-level on-the-wire pixmap data, that is, XImages. + To get this info, you should be looking at XImage->bits_per_pixel + instead. (And allocating the data for your XImage structures by + multiplying ximage->bytes_per_line by ximage->height.) + + Still, it can be useful to know bits_per_pixel before the XImage exists. + + XCreateImage calls _XGetBitsPerPixel to figure this out, but that function + is private to Xlib. + + For some reason, _XGetBitsPerPixel tries a hard-coded list of depths if + it doesn't find a matching pixmap format, but I (Dave Odell) couldn't + find any justification for this in the X11 spec. And the XFree86 CVS + repository doesn't quite go back far enough to shed any light on what + the deal is with that. + http://cvsweb.xfree86.org/cvsweb/xc/lib/X11/ImUtil.c + + The hard-coded list apparently was added between X11R5 and X11R6. + See <ftp://ftp.x.org/pub/>. + */ +int +visual_pixmap_depth (Screen *screen, Visual *visual) +{ + Display *dpy = DisplayOfScreen (screen); + int vdepth = visual_depth (screen, visual); + int pdepth = vdepth; + int i, pfvc = 0; + XPixmapFormatValues *pfv = XListPixmapFormats (dpy, &pfvc); + + /* Return the first matching depth in the pixmap formats. If there are no + matching pixmap formats (which shouldn't be able to happen at all) then + return the visual depth instead. */ + for (i = 0; i < pfvc; i++) + if (pfv[i].depth == vdepth) + { + pdepth = pfv[i].bits_per_pixel; + break; + } + if (pfv) + XFree (pfv); + return pdepth; +} + + +int +visual_class (Screen *screen, Visual *visual) +{ + XVisualInfo *vi_out = visual_info (screen, visual); + int c = vi_out [0].class; + XFree ((char *) vi_out); + return c; +} + +Bool +has_writable_cells (Screen *screen, Visual *visual) +{ + switch (visual_class (screen, visual)) + { + case GrayScale: /* Mappable grays. */ + case PseudoColor: /* Mappable colors. */ + case DirectColor: /* Like TrueColor, but with three colormaps: + one each for red, green, and blue. */ + return True; + case StaticGray: /* Fixed grays. */ + case TrueColor: /* Fixed colors. */ + case StaticColor: /* Like PseudoColor with an unmodifiable colormap. */ + return False; + default: + abort(); + return False; + } +} + +void +describe_visual (FILE *f, Screen *screen, Visual *visual, Bool private_cmap_p) +{ + char n[10]; + XVisualInfo *vi_out = visual_info (screen, visual); + if (private_cmap_p) + sprintf(n, "%3d", vi_out->colormap_size); + else + strcpy(n, "default"); + + fprintf (f, "0x%02x (%s depth: %2d, cmap: %s)\n", + (unsigned int) vi_out->visualid, + (vi_out->class == StaticGray ? "StaticGray, " : + vi_out->class == StaticColor ? "StaticColor," : + vi_out->class == TrueColor ? "TrueColor, " : + vi_out->class == GrayScale ? "GrayScale, " : + vi_out->class == PseudoColor ? "PseudoColor," : + vi_out->class == DirectColor ? "DirectColor," : + "UNKNOWN: "), + vi_out->depth, n); + XFree ((char *) vi_out); +} + +int +screen_number (Screen *screen) +{ + Display *dpy = DisplayOfScreen (screen); + int i; + for (i = 0; i < ScreenCount (dpy); i++) + if (ScreenOfDisplay (dpy, i) == screen) + return i; + abort (); + return 0; +} + +int +visual_cells (Screen *screen, Visual *visual) +{ + XVisualInfo *vi_out = visual_info (screen, visual); + int c = vi_out [0].colormap_size; + XFree ((char *) vi_out); + return c; +} + +Visual * +find_similar_visual(Screen *screen, Visual *old_visual) +{ + Display *dpy = DisplayOfScreen (screen); + XVisualInfo vi_in, *vi_out; + Visual *result = 0; + int out_count; + + vi_in.screen = screen_number (screen); + vi_in.class = visual_class (screen, old_visual); + vi_in.depth = visual_depth (screen, old_visual); + + /* Look for a visual of the same class and depth. + */ + vi_out = XGetVisualInfo (dpy, (VisualScreenMask | VisualClassMask | + VisualDepthMask), + &vi_in, &out_count); + if (vi_out && out_count > 0) + result = vi_out[0].visual; + if (vi_out) XFree (vi_out); + vi_out = 0; + + /* Failing that, look for a visual of the same class. + */ + if (!result) + { + vi_out = XGetVisualInfo (dpy, (VisualScreenMask | VisualClassMask), + &vi_in, &out_count); + if (vi_out && out_count > 0) + result = vi_out[0].visual; + if (vi_out) XFree (vi_out); + vi_out = 0; + } + + /* Failing that, return the default visual. */ + if (!result) + result = DefaultVisualOfScreen (screen); + + return result; +} + + +void +visual_rgb_masks (Screen *screen, Visual *visual, unsigned long *red_mask, + unsigned long *green_mask, unsigned long *blue_mask) +{ + XVisualInfo *vi_out = visual_info (screen, visual); + *red_mask = vi_out->red_mask; + *green_mask = vi_out->green_mask; + *blue_mask = vi_out->blue_mask; + XFree ((char *) vi_out); +} |