SDL  2.0
SDL_nullvideo.c
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1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2016 Sam Lantinga <slouken@libsdl.org>
4 
5  This software is provided 'as-is', without any express or implied
6  warranty. In no event will the authors be held liable for any damages
7  arising from the use of this software.
8 
9  Permission is granted to anyone to use this software for any purpose,
10  including commercial applications, and to alter it and redistribute it
11  freely, subject to the following restrictions:
12 
13  1. The origin of this software must not be misrepresented; you must not
14  claim that you wrote the original software. If you use this software
15  in a product, an acknowledgment in the product documentation would be
16  appreciated but is not required.
17  2. Altered source versions must be plainly marked as such, and must not be
18  misrepresented as being the original software.
19  3. This notice may not be removed or altered from any source distribution.
20 */
21 #include "../../SDL_internal.h"
22 
23 #if SDL_VIDEO_DRIVER_DUMMY
24 
25 /* Dummy SDL video driver implementation; this is just enough to make an
26  * SDL-based application THINK it's got a working video driver, for
27  * applications that call SDL_Init(SDL_INIT_VIDEO) when they don't need it,
28  * and also for use as a collection of stubs when porting SDL to a new
29  * platform for which you haven't yet written a valid video driver.
30  *
31  * This is also a great way to determine bottlenecks: if you think that SDL
32  * is a performance problem for a given platform, enable this driver, and
33  * then see if your application runs faster without video overhead.
34  *
35  * Initial work by Ryan C. Gordon (icculus@icculus.org). A good portion
36  * of this was cut-and-pasted from Stephane Peter's work in the AAlib
37  * SDL video driver. Renamed to "DUMMY" by Sam Lantinga.
38  */
39 
40 #include "SDL_video.h"
41 #include "SDL_mouse.h"
42 #include "../SDL_sysvideo.h"
43 #include "../SDL_pixels_c.h"
44 #include "../../events/SDL_events_c.h"
45 
46 #include "SDL_nullvideo.h"
47 #include "SDL_nullevents_c.h"
48 #include "SDL_nullframebuffer_c.h"
49 
50 #define DUMMYVID_DRIVER_NAME "dummy"
51 
52 /* Initialization/Query functions */
53 static int DUMMY_VideoInit(_THIS);
54 static int DUMMY_SetDisplayMode(_THIS, SDL_VideoDisplay * display, SDL_DisplayMode * mode);
55 static void DUMMY_VideoQuit(_THIS);
56 
57 /* DUMMY driver bootstrap functions */
58 
59 static int
60 DUMMY_Available(void)
61 {
62  const char *envr = SDL_getenv("SDL_VIDEODRIVER");
63  if ((envr) && (SDL_strcmp(envr, DUMMYVID_DRIVER_NAME) == 0)) {
64  return (1);
65  }
66 
67  return (0);
68 }
69 
70 static void
71 DUMMY_DeleteDevice(SDL_VideoDevice * device)
72 {
73  SDL_free(device);
74 }
75 
76 static SDL_VideoDevice *
77 DUMMY_CreateDevice(int devindex)
78 {
79  SDL_VideoDevice *device;
80 
81  /* Initialize all variables that we clean on shutdown */
82  device = (SDL_VideoDevice *) SDL_calloc(1, sizeof(SDL_VideoDevice));
83  if (!device) {
85  return (0);
86  }
87 
88  /* Set the function pointers */
89  device->VideoInit = DUMMY_VideoInit;
90  device->VideoQuit = DUMMY_VideoQuit;
91  device->SetDisplayMode = DUMMY_SetDisplayMode;
92  device->PumpEvents = DUMMY_PumpEvents;
96 
97  device->free = DUMMY_DeleteDevice;
98 
99  return device;
100 }
101 
102 VideoBootStrap DUMMY_bootstrap = {
103  DUMMYVID_DRIVER_NAME, "SDL dummy video driver",
104  DUMMY_Available, DUMMY_CreateDevice
105 };
106 
107 
108 int
109 DUMMY_VideoInit(_THIS)
110 {
112 
113  /* Use a fake 32-bpp desktop mode */
115  mode.w = 1024;
116  mode.h = 768;
117  mode.refresh_rate = 0;
118  mode.driverdata = NULL;
119  if (SDL_AddBasicVideoDisplay(&mode) < 0) {
120  return -1;
121  }
122 
123  SDL_zero(mode);
124  SDL_AddDisplayMode(&_this->displays[0], &mode);
125 
126  /* We're done! */
127  return 0;
128 }
129 
130 static int
131 DUMMY_SetDisplayMode(_THIS, SDL_VideoDisplay * display, SDL_DisplayMode * mode)
132 {
133  return 0;
134 }
135 
136 void
137 DUMMY_VideoQuit(_THIS)
138 {
139 }
140 
141 #endif /* SDL_VIDEO_DRIVER_DUMMY */
142 
143 /* vi: set ts=4 sw=4 expandtab: */
void(* free)(_THIS)
Definition: SDL_sysvideo.h:358
int SDL_AddBasicVideoDisplay(const SDL_DisplayMode *desktop_mode)
Definition: SDL_video.c:577
The structure that defines a display mode.
Definition: SDL_video.h:53
int(* SetDisplayMode)(_THIS, SDL_VideoDisplay *display, SDL_DisplayMode *mode)
Definition: SDL_sysvideo.h:197
static SDL_VideoDevice * _this
Definition: SDL_video.c:118
void * SDL_calloc(size_t nmemb, size_t size)
void SDL_DUMMY_DestroyWindowFramebuffer(_THIS, SDL_Window *window)
int SDL_DUMMY_UpdateWindowFramebuffer(_THIS, SDL_Window *window, const SDL_Rect *rects, int numrects)
#define _THIS
void SDL_free(void *mem)
void * driverdata
Definition: SDL_video.h:59
GLenum mode
SDL_VideoDisplay * displays
Definition: SDL_sysvideo.h:293
#define SDL_zero(x)
Definition: SDL_stdinc.h:361
void DUMMY_PumpEvents(_THIS)
#define SDL_getenv
void(* DestroyWindowFramebuffer)(_THIS, SDL_Window *window)
Definition: SDL_sysvideo.h:230
#define NULL
Definition: begin_code.h:143
#define SDL_OutOfMemory()
Definition: SDL_error.h:52
void(* VideoQuit)(_THIS)
Definition: SDL_sysvideo.h:164
SDL_bool SDL_AddDisplayMode(SDL_VideoDisplay *display, const SDL_DisplayMode *mode)
Definition: SDL_video.c:728
int(* VideoInit)(_THIS)
Definition: SDL_sysvideo.h:158
int(* UpdateWindowFramebuffer)(_THIS, SDL_Window *window, const SDL_Rect *rects, int numrects)
Definition: SDL_sysvideo.h:229
#define SDL_strcmp
Uint32 format
Definition: SDL_video.h:55
int(* CreateWindowFramebuffer)(_THIS, SDL_Window *window, Uint32 *format, void **pixels, int *pitch)
Definition: SDL_sysvideo.h:228
int SDL_DUMMY_CreateWindowFramebuffer(_THIS, SDL_Window *window, Uint32 *format, void **pixels, int *pitch)
void(* PumpEvents)(_THIS)
Definition: SDL_sysvideo.h:262