Mercurial > hg > forks > gldragon

comparison gldragon.cpp @ 42:3c7e1d3fa5a2

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Implement OpengL extension handling through new header file dmglexts.h to "define" the entrypoints we require and some wonderful preprocessor macro magic to add checks for them via SDL_GL_ExtensionSupported() and initialize function pointers with SDL_GL_GetProcAddress().
author Matti Hamalainen <ccr@tnsp.org>
date Thu, 05 Dec 2019 21:05:43 +0200
parents 4de11a54215a
children d93b1c2690f8
comparison
equal deleted inserted replaced
41:eaa3e8575c12 42:3c7e1d3fa5a2
37 SDL_GLContext dmGLContext = NULL; 37 SDL_GLContext dmGLContext = NULL;
38 38
39 39
40 /* Helpers 40 /* Helpers
41 */ 41 */
42 #ifdef GL_GLEXT_PROTOTYPES
43 #define DM_GLEXT_INIT(extproctype, extprocname) /* stub */
44 #else
45 // GL_GLEXT_PROTOTYPES not defined
46
47 #define DM_GLEXT_INIT(extproctype, extprocname) extproctype extprocname = NULL;
48 #include "dmglexts.h"
49 #undef DM_GLEXT_INIT
50
51
52 void * dmGLExtTry(const std::string &name)
53 {
54 bool res = SDL_GL_ExtensionSupported(name.c_str());
55 void *ptr = SDL_GL_GetProcAddress(name.c_str());
56 res = true;
57
58 printf(" - Checking '%s' : %s : %p\n",
59 name.c_str(),
60 res ? "YES" : "no",
61 ptr);
62
63 if (res && ptr != NULL)
64 return ptr;
65 else
66 return NULL;
67 }
68
69 void * dmGLExtInit(const std::string &name, bool &status)
70 {
71 void *ptr;
72
73 if ((ptr = dmGLExtTry(name)) != NULL)
74 return ptr;
75 else
76 if ((ptr = dmGLExtTry(name + "EXT")) != NULL)
77 return ptr;
78 else
79 if ((ptr = dmGLExtTry(name + "ARB")) != NULL)
80 return ptr;
81
82 status = false;
83 return NULL;
84 }
85
86
87 #define DM_GLEXT_INIT(extproctype, extprocname) \
88 extprocname = (extproctype) dmGLExtInit(#extprocname, status);
89
90 #endif
91
92
93
94 bool dmInitGLExtensions(void)
95 {
96 #ifdef GL_GLEXT_PROTOTYPES
97 return true;
98 #else
99 bool status = true;
100 #include "dmglexts.h"
101 return status;
102 #endif
103 }
104
105
42 bool dmInitSDLGL(const int width, const int height, const char *title) 106 bool dmInitSDLGL(const int width, const int height, const char *title)
43 { 107 {
44 int ret; 108 int ret;
45 std::string msg; 109 std::string msg;
46 110
111 { 175 {
112 printf("ERROR: Could not set vsync mode to %s.\n", 176 printf("ERROR: Could not set vsync mode to %s.\n",
113 msg.c_str()); 177 msg.c_str());
114 return false; 178 return false;
115 } 179 }
180
181 // Get/initialize OpenGL extension function pointers
182 if (optUseShaders && !dmInitGLExtensions())
183 return false;
116 184
117 // Dump some information 185 // Dump some information
118 printf( 186 printf(
119 "GL_VENDOR : %s\n" 187 "GL_VENDOR : %s\n"
120 "GL_RENDERER : %s\n" 188 "GL_RENDERER : %s\n"