Skip to content

Commit

Permalink
OpenGL2: Fallback to OpenGL ES if OpenGL fails
Browse files Browse the repository at this point in the history
  • Loading branch information
@zturtleman
zturtleman committed Jun 6, 2024
1 parent 551fa6c commit f869bff
Show file tree
Hide file tree
Showing 3 changed files with 104 additions and 103 deletions.
7 changes: 4 additions & 3 deletions README.md
View file
Original file line number Diff line number Diff line change
Expand Up @@ -168,11 +168,12 @@ embedded System-on-a-Chip and mobile platforms.

The opengl1 renderer does not have OpenGL ES support.

The `r_useOpenGLES` cvar controls whether to use OpenGL or OpenGL ES API.
Set to -1 for auto (default), 0 for OpenGL, and 1 for OpenGL ES. It should be
The opengl2 renderer will try both OpenGL and OpenGL ES APIs to find one that
works. The `r_preferOpenGLES` cvar controls which API to try first.
Set it to -1 for auto (default), 0 for OpenGL, and 1 for OpenGL ES. It should be
set using command line arguments:

ioquake3 +set cl_renderer opengl2 +set r_useOpenGLES 1
ioquake3 +set cl_renderer opengl2 +set r_preferOpenGLES 1


# Console
Expand Down
192 changes: 96 additions & 96 deletions code/sdl/sdl_glimp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -52,7 +52,7 @@ cvar_t *r_allowSoftwareGL; // Don't abort out if a hardware visual can't be obta
cvar_t *r_allowResize; // make window resizable
cvar_t *r_centerWindow;
cvar_t *r_sdlDriver;
cvar_t *r_useOpenGLES;
cvar_t *r_preferOpenGLES;

int qglMajorVersion, qglMinorVersion;
int qglesMajorVersion, qglesMinorVersion;
Expand Down Expand Up @@ -394,6 +394,12 @@ GLimp_SetMode
*/
static int GLimp_SetMode(int mode, qboolean fullscreen, qboolean noborder, qboolean fixedFunction)
{
struct GLimp_ContextType {
int profileMask;
int majorVersion;
int minorVersion;
} contexts[3];
int numContexts, type;
const char *glstring;
int perChannelColorBits;
int colorBits, depthBits, stencilBits;
Expand Down Expand Up @@ -524,6 +530,48 @@ static int GLimp_SetMode(int mode, qboolean fullscreen, qboolean noborder, qbool
stencilBits = r_stencilbits->value;
samples = r_ext_multisample->value;

numContexts = 0;

if ( !fixedFunction ) {
int profileMask;
qboolean preferOpenGLES;

SDL_GL_ResetAttributes();
SDL_GL_GetAttribute( SDL_GL_CONTEXT_PROFILE_MASK, &profileMask );

preferOpenGLES = ( r_preferOpenGLES->integer == 1 ||
( r_preferOpenGLES->integer == -1 && profileMask == SDL_GL_CONTEXT_PROFILE_ES ) );

if ( preferOpenGLES ) {
contexts[numContexts].profileMask = SDL_GL_CONTEXT_PROFILE_ES;
contexts[numContexts].majorVersion = 2;
contexts[numContexts].minorVersion = 0;
numContexts++;
}

contexts[numContexts].profileMask = SDL_GL_CONTEXT_PROFILE_CORE;
contexts[numContexts].majorVersion = 3;
contexts[numContexts].minorVersion = 2;
numContexts++;

contexts[numContexts].profileMask = 0;
contexts[numContexts].majorVersion = 2;
contexts[numContexts].minorVersion = 0;
numContexts++;

if ( !preferOpenGLES ) {
contexts[numContexts].profileMask = SDL_GL_CONTEXT_PROFILE_ES;
contexts[numContexts].majorVersion = 2;
contexts[numContexts].minorVersion = 0;
numContexts++;
}
} else {
contexts[numContexts].profileMask = 0;
contexts[numContexts].majorVersion = 1;
contexts[numContexts].minorVersion = 1;
numContexts++;
}

for (i = 0; i < 16; i++)
{
int testColorBits, testDepthBits, testStencilBits;
Expand Down Expand Up @@ -656,116 +704,68 @@ static int GLimp_SetMode(int mode, qboolean fullscreen, qboolean noborder, qbool

SDL_SetWindowIcon( SDL_window, icon );

if (!fixedFunction)
{
int profileMask;

SDL_GL_GetAttribute( SDL_GL_CONTEXT_PROFILE_MASK, &profileMask );

if ( r_useOpenGLES->integer == 1 || ( r_useOpenGLES->integer == -1 && profileMask == SDL_GL_CONTEXT_PROFILE_ES ) )
{
ri.Printf( PRINT_ALL, "Trying to get an OpenGL ES 2.0 context\n" );
SDL_GL_SetAttribute( SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES );
SDL_GL_SetAttribute( SDL_GL_CONTEXT_MAJOR_VERSION, 2 );
SDL_GL_SetAttribute( SDL_GL_CONTEXT_MINOR_VERSION, 0 );
for ( type = 0; type < numContexts; type++ ) {
char contextName[32];

SDL_glContext = SDL_GL_CreateContext( SDL_window );
if ( !SDL_glContext )
{
ri.Printf( PRINT_ALL, "SDL_GL_CreateContext failed: %s\n", SDL_GetError() );
}
else
{
ri.Printf( PRINT_ALL, "SDL_GL_CreateContext succeeded.\n" );

if ( !GLimp_GetProcAddresses( fixedFunction ) )
{
ri.Printf( PRINT_ALL, "GLimp_GetProcAddresses() failed for OpenGL ES 2.0 context\n" );
GLimp_ClearProcAddresses();
SDL_GL_DeleteContext( SDL_glContext );
SDL_glContext = NULL;
}
}
switch ( contexts[type].profileMask ) {
default:
case 0:
Com_sprintf( contextName, sizeof( contextName ), "OpenGL %d.%d",
contexts[type].majorVersion, contexts[type].minorVersion );
break;
case SDL_GL_CONTEXT_PROFILE_CORE:
Com_sprintf( contextName, sizeof( contextName ), "OpenGL %d.%d Core",
contexts[type].majorVersion, contexts[type].minorVersion );
break;
case SDL_GL_CONTEXT_PROFILE_ES:
Com_sprintf( contextName, sizeof( contextName ), "OpenGL ES %d.%d",
contexts[type].majorVersion, contexts[type].minorVersion );
break;
}

if ( !SDL_glContext )
{
ri.Printf( PRINT_ALL, "Trying to get an OpenGL 3.2 core context\n" );
SDL_GL_SetAttribute( SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE );
SDL_GL_SetAttribute( SDL_GL_CONTEXT_MAJOR_VERSION, 3 );
SDL_GL_SetAttribute( SDL_GL_CONTEXT_MINOR_VERSION, 2 );

SDL_glContext = SDL_GL_CreateContext( SDL_window );
if ( !SDL_glContext )
{
ri.Printf( PRINT_ALL, "SDL_GL_CreateContext failed: %s\n", SDL_GetError() );
}
else
{
const char *renderer;

ri.Printf( PRINT_ALL, "SDL_GL_CreateContext succeeded.\n" );

if ( GLimp_GetProcAddresses( fixedFunction ) )
{
renderer = (const char *)qglGetString( GL_RENDERER );
}
else
{
ri.Printf( PRINT_ALL, "GLimp_GetProcAddresses() failed for OpenGL 3.2 core context\n" );
renderer = NULL;
}

if ( !renderer || strstr( renderer, "Software Renderer" ) || strstr( renderer, "Software Rasterizer" ) )
{
if ( renderer )
ri.Printf(PRINT_ALL, "GL_RENDERER is %s, rejecting context\n", renderer);

GLimp_ClearProcAddresses();
SDL_GL_DeleteContext( SDL_glContext );
SDL_glContext = NULL;
}
}
}
SDL_GL_SetAttribute( SDL_GL_CONTEXT_PROFILE_MASK, contexts[type].profileMask );
SDL_GL_SetAttribute( SDL_GL_CONTEXT_MAJOR_VERSION, contexts[type].majorVersion );
SDL_GL_SetAttribute( SDL_GL_CONTEXT_MINOR_VERSION, contexts[type].minorVersion );

SDL_glContext = SDL_GL_CreateContext( SDL_window );
if ( !SDL_glContext )
{
ri.Printf( PRINT_ALL, "Trying to get an OpenGL 2.0 context\n" );

SDL_GL_SetAttribute( SDL_GL_CONTEXT_PROFILE_MASK, 0 );
SDL_GL_SetAttribute( SDL_GL_CONTEXT_MAJOR_VERSION, 2 );
SDL_GL_SetAttribute( SDL_GL_CONTEXT_MINOR_VERSION, 0 );
}
}
else
{
SDL_GL_SetAttribute( SDL_GL_CONTEXT_PROFILE_MASK, 0 );
SDL_GL_SetAttribute( SDL_GL_CONTEXT_MAJOR_VERSION, 1 );
SDL_GL_SetAttribute( SDL_GL_CONTEXT_MINOR_VERSION, 1 );

SDL_glContext = NULL;
}

if ( !SDL_glContext )
{
if( ( SDL_glContext = SDL_GL_CreateContext( SDL_window ) ) == NULL )
{
ri.Printf( PRINT_DEVELOPER, "SDL_GL_CreateContext failed: %s\n", SDL_GetError( ) );
SDL_DestroyWindow( SDL_window );
SDL_window = NULL;
ri.Printf( PRINT_ALL, "SDL_GL_CreateContext() for %s context failed: %s\n", contextName, SDL_GetError() );
continue;
}

if ( !GLimp_GetProcAddresses( fixedFunction ) )
{
ri.Printf( PRINT_ALL, "GLimp_GetProcAddresses() failed\n" );
ri.Printf( PRINT_ALL, "GLimp_GetProcAddresses() for %s context failed\n", contextName );
GLimp_ClearProcAddresses();
SDL_GL_DeleteContext( SDL_glContext );
SDL_glContext = NULL;
SDL_DestroyWindow( SDL_window );
SDL_window = NULL;
continue;
}

if ( contexts[type].profileMask == SDL_GL_CONTEXT_PROFILE_CORE ) {
const char *renderer;

renderer = (const char *)qglGetString( GL_RENDERER );

if ( !renderer || strstr( renderer, "Software Renderer" ) || strstr( renderer, "Software Rasterizer" ) )
{
ri.Printf( PRINT_ALL, "GL_RENDERER is %s, rejecting %s context\n", renderer, contextName );

GLimp_ClearProcAddresses();
SDL_GL_DeleteContext( SDL_glContext );
SDL_glContext = NULL;
continue;
}
}

break;
}

if ( !SDL_glContext ) {
SDL_DestroyWindow( SDL_window );
SDL_window = NULL;
continue;
}

qglClearColor( 0, 0, 0, 1 );
Expand Down Expand Up @@ -1055,7 +1055,7 @@ void GLimp_Init( qboolean fixedFunction )
r_sdlDriver = ri.Cvar_Get( "r_sdlDriver", "", CVAR_ROM );
r_allowResize = ri.Cvar_Get( "r_allowResize", "0", CVAR_ARCHIVE | CVAR_LATCH );
r_centerWindow = ri.Cvar_Get( "r_centerWindow", "0", CVAR_ARCHIVE | CVAR_LATCH );
r_useOpenGLES = ri.Cvar_Get( "r_useOpenGLES", "-1", CVAR_ARCHIVE | CVAR_LATCH );
r_preferOpenGLES = ri.Cvar_Get( "r_preferOpenGLES", "-1", CVAR_ARCHIVE | CVAR_LATCH );

if( ri.Cvar_VariableIntegerValue( "com_abnormalExit" ) )
{
Expand Down
8 changes: 4 additions & 4 deletions opengl2-readme.md
View file
Original file line number Diff line number Diff line change
Expand Up @@ -65,10 +65,10 @@ For Win32:

Cvars for API:

* `r_useOpenGLES` - This enables using OpenGL ES 2+.
Many features are not supported such as sun shadows and HDR.
1 - Use OpenGL ES.
0 - Use desktop OpenGL.
* `r_preferOpenGLES` - This sets the preference for using OpenGL or OpenGL ES 2.
Many features are not supported when using OpenGL ES such as sun shadows and HDR.
1 - Prefer OpenGL ES 2+.
0 - Prefer desktop OpenGL.
-1 - Automatically pick (default).

Cvars for simple rendering features:
Expand Down

0 comments on commit f869bff

Please sign in to comment.