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#include <mbgl/gl/headless_display.hpp>
#include <OpenGL/OpenGL.h>
#include <stdexcept>
#include <string>
namespace mbgl {
class HeadlessDisplay::Impl {
public:
Impl();
~Impl();
CGLPixelFormatObj pixelFormat = nullptr;
};
HeadlessDisplay::Impl::Impl() {
// TODO: test if OpenGL 4.1 with GL_ARB_ES2_compatibility is supported
// If it is, use kCGLOGLPVersion_3_2_Core and enable that extension.
CGLPixelFormatAttribute attributes[] = {
kCGLPFAOpenGLProfile, static_cast<CGLPixelFormatAttribute>(kCGLOGLPVersion_Legacy),
// Not adding kCGLPFAAccelerated, as this will make headless rendering impossible when running in VMs.
kCGLPFAClosestPolicy,
kCGLPFAAccumSize, static_cast<CGLPixelFormatAttribute>(32),
kCGLPFAColorSize, static_cast<CGLPixelFormatAttribute>(24),
kCGLPFAAlphaSize, static_cast<CGLPixelFormatAttribute>(8),
kCGLPFADepthSize, static_cast<CGLPixelFormatAttribute>(16),
kCGLPFAStencilSize, static_cast<CGLPixelFormatAttribute>(8),
kCGLPFASupportsAutomaticGraphicsSwitching,
kCGLPFAAllowOfflineRenderers, // Allows using the integrated GPU
static_cast<CGLPixelFormatAttribute>(0)
};
GLint num;
CGLError error = CGLChoosePixelFormat(attributes, &pixelFormat, &num);
if (error != kCGLNoError) {
throw std::runtime_error(std::string("Error choosing pixel format:") + CGLErrorString(error) + "\n");
}
if (num <= 0) {
throw std::runtime_error("No pixel formats found.");
}
}
HeadlessDisplay::Impl::~Impl() {
CGLDestroyPixelFormat(pixelFormat);
}
template <>
CGLPixelFormatObj HeadlessDisplay::attribute() const {
return impl->pixelFormat;
}
HeadlessDisplay::HeadlessDisplay()
: impl(std::make_unique<Impl>()) {
}
HeadlessDisplay::~HeadlessDisplay() {
}
} // namespace mbgl
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