/// <summary>
/// Initializes the rendering API, potentially using lower settings in the event that
/// the initial attempt to initialize the API failed.
/// </summary>
/// <param name="graphicsConfiguration">The platform configuration settings.</param>
/// <param name="attempt">The number of attempts which have been made to find a working configuration.</param>
/// <returns><see langword="true"/> if a configuration was provided; otherwise, <see langword="false"/>.</returns>
protected virtual Boolean InitializeRenderingAPI(UltravioletGraphicsConfiguration graphicsConfiguration, Int32 attempt)
{
return(false);
}
/// <inheritdoc/>
protected override Boolean InitializeRenderingAPI(UltravioletGraphicsConfiguration graphicsConfig, Int32 attempt)
{
var glGraphicsConfig = graphicsConfig as OpenGLGraphicsConfiguration;
if (glGraphicsConfig == null)
{
throw new InvalidOperationException(UltravioletStrings.MissingGraphicsConfiguration);
}
if (SDL_GL_SetAttribute(SDL_GL_FRAMEBUFFER_SRGB_CAPABLE, glGraphicsConfig.SrgbBuffersEnabled ? 1 : 0) < 0)
{
throw new SDL2Exception();
}
if (SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, glGraphicsConfig.MultiSampleBuffers) < 0)
{
throw new SDL2Exception();
}
if (SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, glGraphicsConfig.MultiSampleSamples) < 0)
{
throw new SDL2Exception();
}
switch (attempt)
{
case 0:
// Attempt #0: Try with specified configurations.
return(true);
case 1:
// Attempt #1: Try turning off sRGB.
if (glGraphicsConfig.SrgbBuffersEnabled)
{
if (SDL_GL_SetAttribute(SDL_GL_FRAMEBUFFER_SRGB_CAPABLE, 0) < 0)
{
throw new SDL2Exception();
}
return(true);
}
else
{
goto case 2;
}
case 2:
// Attempt #2: Try turning off multisampling.
if (glGraphicsConfig.MultiSampleBuffers > 0 || glGraphicsConfig.MultiSampleSamples > 0)
{
if (SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, 0) < 0)
{
throw new SDL2Exception();
}
if (SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, 0) < 0)
{
throw new SDL2Exception();
}
return(true);
}
else
{
goto case 3;
}
case 3:
// Attempt #3: Try turning off sRGB and multisampling.
if (glGraphicsConfig.SrgbBuffersEnabled)
{
if (SDL_GL_SetAttribute(SDL_GL_FRAMEBUFFER_SRGB_CAPABLE, 0) < 0)
{
throw new SDL2Exception();
}
if (SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, 0) < 0)
{
throw new SDL2Exception();
}
if (SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, 0) < 0)
{
throw new SDL2Exception();
}
return(true);
}
else
{
goto default;
}
default:
return(false);
}
}
