1 /*
2   Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>
3 
4   This software is provided 'as-is', without any express or implied
5   warranty.  In no event will the authors be held liable for any damages
6   arising from the use of this software.
7 
8   Permission is granted to anyone to use this software for any purpose,
9   including commercial applications, and to alter it and redistribute it
10   freely.
11 */
12 
13 /* Program to test querying of display info */
14 
15 #include "SDL.h"
16 
17 #include <stdio.h>
18 #include <stdlib.h>
19 
20 static void
print_mode(const char * prefix,const SDL_DisplayMode * mode)21 print_mode(const char *prefix, const SDL_DisplayMode *mode)
22 {
23     if (!mode)
24         return;
25 
26     SDL_Log("%s: fmt=%s w=%d h=%d refresh=%d\n",
27             prefix, SDL_GetPixelFormatName(mode->format),
28             mode->w, mode->h, mode->refresh_rate);
29 }
30 
31 int
main(int argc,char * argv[])32 main(int argc, char *argv[])
33 {
34     SDL_DisplayMode mode;
35     int num_displays, dpy;
36 
37     /* Enable standard application logging */
38     SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
39 
40     /* Load the SDL library */
41     if (SDL_Init(SDL_INIT_VIDEO) < 0) {
42         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize SDL: %s\n", SDL_GetError());
43         return 1;
44     }
45 
46     SDL_Log("Using video target '%s'.\n", SDL_GetCurrentVideoDriver());
47     num_displays = SDL_GetNumVideoDisplays();
48 
49     SDL_Log("See %d displays.\n", num_displays);
50 
51     for (dpy = 0; dpy < num_displays; dpy++) {
52         const int num_modes = SDL_GetNumDisplayModes(dpy);
53         SDL_Rect rect = { 0, 0, 0, 0 };
54         float ddpi, hdpi, vdpi;
55         int m;
56 
57         SDL_GetDisplayBounds(dpy, &rect);
58         SDL_Log("%d: \"%s\" (%dx%d, (%d, %d)), %d modes.\n", dpy, SDL_GetDisplayName(dpy), rect.w, rect.h, rect.x, rect.y, num_modes);
59 
60         if (SDL_GetDisplayDPI(dpy, &ddpi, &hdpi, &vdpi) == -1) {
61             SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "    DPI: failed to query (%s)\n", SDL_GetError());
62         } else {
63             SDL_Log("    DPI: ddpi=%f; hdpi=%f; vdpi=%f\n", ddpi, hdpi, vdpi);
64         }
65 
66         if (SDL_GetCurrentDisplayMode(dpy, &mode) == -1) {
67             SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "    CURRENT: failed to query (%s)\n", SDL_GetError());
68         } else {
69             print_mode("CURRENT", &mode);
70         }
71 
72         if (SDL_GetDesktopDisplayMode(dpy, &mode) == -1) {
73             SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "    DESKTOP: failed to query (%s)\n", SDL_GetError());
74         } else {
75             print_mode("DESKTOP", &mode);
76         }
77 
78         for (m = 0; m < num_modes; m++) {
79             if (SDL_GetDisplayMode(dpy, m, &mode) == -1) {
80                 SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "    MODE %d: failed to query (%s)\n", m, SDL_GetError());
81             } else {
82                 char prefix[64];
83                 SDL_snprintf(prefix, sizeof (prefix), "    MODE %d", m);
84                 print_mode(prefix, &mode);
85             }
86         }
87 
88         SDL_Log("\n");
89     }
90 
91     SDL_Quit();
92     return 0;
93 }
94 
95 /* vi: set ts=4 sw=4 expandtab: */
96 
97