58 lines
1.7 KiB
C++
58 lines
1.7 KiB
C++
#pragma once
|
|
|
|
#include <mbgl/map/map_observer.hpp>
|
|
|
|
#include <memory>
|
|
#include <mutex>
|
|
|
|
namespace mbgl {
|
|
|
|
namespace gl {
|
|
class Context;
|
|
using ProcAddress = void (*)();
|
|
} // namespace gl
|
|
|
|
class BackendScope;
|
|
|
|
class Backend : public MapObserver {
|
|
public:
|
|
Backend();
|
|
virtual ~Backend();
|
|
|
|
// Returns the backend's context which manages OpenGL state.
|
|
gl::Context& getContext();
|
|
|
|
// Called when the map needs to be rendered; the backend should call Map::render() at some point
|
|
// in the near future. (Not called for Map::renderStill() mode.)
|
|
virtual void invalidate() = 0;
|
|
|
|
protected:
|
|
// Called with the name of an OpenGL extension that should be loaded. Backend implementations
|
|
// must call the API-specific version that obtains the function pointer for this function,
|
|
// or a null pointer if unsupported/unavailable.
|
|
virtual gl::ProcAddress initializeExtension(const char*) = 0;
|
|
|
|
// Called when the backend's GL context needs to be made active or inactive. These are called,
|
|
// as a matched pair, in four situations:
|
|
//
|
|
// 1. When releasing GL resources during Map destruction
|
|
// 2. When calling a CustomLayerInitializeFunction, during Map::addLayer
|
|
// 3. When calling a CustomLayerDeinitializeFunction, during Map::removeLayer
|
|
// 4. When rendering for Map::renderStill
|
|
//
|
|
// They are *not* called for Map::render; it is assumed that the correct context is already
|
|
// activated prior to calling Map::render.
|
|
virtual void activate() = 0;
|
|
virtual void deactivate() = 0;
|
|
|
|
protected:
|
|
std::unique_ptr<gl::Context> context;
|
|
|
|
private:
|
|
std::once_flag initialized;
|
|
|
|
friend class BackendScope;
|
|
};
|
|
|
|
} // namespace mbgl
|