// Example C program that ensures the graphic shell works.
// This tests the native layer implmentation without golang.
int main( void )
{
// initialize the window.
gs_set_attr_s(GS_AppName, "Test Window");
long long display = gs_display_init();
if (display == 0)
{
printf("Failed display init.\n");
exit( EXIT_FAILURE );
}
// create the window.
long long shell = gs_shell(display);
printf("display %ld shell %ld\n", (long)display, (long)shell);
long long context = gs_context(&display, &shell);
printf("display %ld shell %ld context %ld\n", (long)display, (long)shell, (long)context);
if (context == 0)
{
printf("Failed context init.\n");
exit( EXIT_FAILURE );
}
gs_shell_open(display);
long x, y, w, h;
gs_size(display, &x, &y, &w, &h);
printf("shell size %ld::%ld ", w, h);
// process user events.
GSEvent gsu = {-1, 0, 0, 0, 0, 0};
while (gs_shell_alive(display))
{
gsu.event = -1;
gsu.mousex = 0;
gsu.mousey = 0;
gsu.key = 0;
gsu.mods = 0;
gsu.scroll = 0;
gs_read_dispatch(display, &gsu);
if (gsu.event >= 0) {
// show current key code
printf("mouse %ld,%ld - ", gsu.mousex, gsu.mousey);
printf("[mods 0x%.2lX] - ", gsu.mods);
if (gsu.event == GS_KeyUp) {
printf("key up 0x%.2lX - ", gsu.key);
} else if (gsu.event == GS_KeyDown) {
printf("key down 0x%.2lX - ", gsu.key);
// test copy and paste.
if (gsu.key == 0x43) { // c key
char *s = gs_clip_copy(display);
printf(" \"%s\"", s);
free(s);
} else if (gsu.key == 0x50) { // p key
gs_clip_paste(display, "test paste string");
}
} else if (gsu.event == GS_ScrollWheel) {
printf("wheel %ld - ", gsu.scroll);
} else {
printf("event %ld - ", gsu.event);
}
printf("\n");
}
gs_swap_buffers(shell);
}
gs_display_dispose(display);
return 0;
};
// gs_context creates an opengl context. Actually it creates two of them.
// The first context is used to find better functions to create the final
// context. Note that the pixel format is done only once for a window so
// it must be correctly chosen.
long gs_context(long long * display, long long * shell)
{
// create the initial context.
HDC hdc = LongToHandle(*shell);
HGLRC initialContext;
int initial_pixelFormat = gs_get_initial_pixelformat(*shell);
if (initial_pixelFormat != 0)
{
initialContext = wglCreateContext(hdc);
if (initialContext != NULL)
{
if (!wglMakeCurrent(hdc, initialContext))
{
wglDeleteContext(initialContext);
initialContext = NULL;
}
}
}
if (initialContext == NULL)
{
return 0; // failed to get even a simple context.
}
// now that there is a context, bind the opengl extensions and fail
// if the supported extensions are too old or if they are not there.
gs_wglGetExtensionsStringEXT = (PFNWGLGETEXTENSIONSSTRINGEXTPROC) wglGetProcAddress( "wglGetExtensionsStringEXT" );
gs_wglSwapIntervalARB = (PFNWGLSWAPINTERVALEXTPROC) wglGetProcAddress( "wglSwapIntervalEXT" );
gs_wglGetExtensionsStringARB = (PFNWGLGETEXTENSIONSSTRINGARBPROC) wglGetProcAddress( "wglGetExtensionsStringARB" );
gs_wglCreateContextAttribsARB = (PFNWGLCREATECONTEXTATTRIBSARBPROC) wglGetProcAddress( "wglCreateContextAttribsARB" );
gs_wglGetPixelFormatAttribivARB = (PFNWGLGETPIXELFORMATATTRIBIVARBPROC) wglGetProcAddress( "wglGetPixelFormatAttribivARB" );
gs_wglChoosePixelFormatARB = (PFNWGLCHOOSEPIXELFORMATARBPROC) wglGetProcAddress( "wglChoosePixelFormatARB" );
if (gs_wglGetExtensionsStringEXT == NULL ||
gs_wglSwapIntervalARB == NULL ||
gs_wglGetExtensionsStringARB == NULL ||
gs_wglCreateContextAttribsARB == NULL ||
gs_wglGetPixelFormatAttribivARB == NULL ||
gs_wglChoosePixelFormatARB == NULL)
{
return 0;
}
// destroy and recreate the window and shell
LPSTR gs_className = TEXT("GS_WIN");
gs_display_dispose(*display);
HMODULE hInstance = GetModuleHandle(NULL);
*display = gs_create_window(hInstance, gs_className);
*shell = gs_shell(*display);
int pixelformat = gs_get_pixelformat(*shell);
if (pixelformat == 0)
{
return 0;
}
// now create the context on the fresh window.
int cnt = 0;
int attribs[40];
hdc = LongToHandle(*shell);
// Use the expected baseline opengl 3.2
attribs[cnt++] = WGL_CONTEXT_MAJOR_VERSION_ARB;
attribs[cnt++] = 3;
attribs[cnt++] = WGL_CONTEXT_MINOR_VERSION_ARB;
attribs[cnt++] = 2;
attribs[cnt++] = WGL_CONTEXT_FLAGS_ARB;
attribs[cnt++] = WGL_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB;
attribs[cnt++] = WGL_CONTEXT_PROFILE_MASK_ARB;
attribs[cnt++] = WGL_CONTEXT_CORE_PROFILE_BIT_ARB;
attribs[cnt++] = 0;
HGLRC context = gs_wglCreateContextAttribsARB( hdc, NULL, attribs );
if (context != NULL)
{
if (wglMakeCurrent(hdc, context))
{
return HandleToLong(context);
}
}
return 0; // failed to get rendering context
}
