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#pragma once
#include <mbgl/style/layer.hpp>
#include <array>
namespace mbgl {
namespace style {
/**
* Parameters that define the current camera position for a `CustomLayerHost::render()` function.
*/
struct CustomLayerRenderParameters {
double width;
double height;
double latitude;
double longitude;
double zoom;
double bearing;
double pitch;
double fieldOfView;
std::array<double, 16> projectionMatrix;
};
class CustomLayerHost {
public:
virtual ~CustomLayerHost() = default;
/**
* Initialize any GL state needed by the custom layer. This method is called once, from the
* main thread, at a point when the GL context is active but before rendering for the first
* time.
*
* Resources that are acquired in this method must be released in the `deinitialize` function.
*/
virtual void initialize() = 0;
/**
* Render the layer. This method is called once per frame. The implementation should not make
* any assumptions about the GL state (other than that the correct context is active). It may
* make changes to the state, and is not required to reset values such as the depth mask, stencil
* mask, and corresponding test flags to their original values.
* Make sure that you are drawing your fragments with a z value of 1 to take advantage of the
* opaque fragment culling in case there are opaque layers above your custom layer.
*/
virtual void render(const CustomLayerRenderParameters&) = 0;
/**
* Called when the system has destroyed the underlying GL context. The
* `deinitialize` function will not be called in this case, however
* `initialize` will be called instead to prepare for a new render.
*
*/
virtual void contextLost() = 0;
/**
* Destroy any GL state needed by the custom layer, and deallocate context, if necessary. This
* method is called once, from the main thread, at a point when the GL context is active.
*
* Note that it may be called even when the `initialize` function has not been called.
*/
virtual void deinitialize() = 0;
};
class CustomLayer : public Layer {
public:
CustomLayer(const std::string& id,
std::unique_ptr<CustomLayerHost> host);
~CustomLayer() final;
// Visibility
void setVisibility(VisibilityType) final;
// Zoom range
void setMinZoom(float) final;
void setMaxZoom(float) final;
// Private implementation
class Impl;
const Impl& impl() const;
Mutable<Impl> mutableImpl() const;
std::unique_ptr<Layer> cloneRef(const std::string& id) const final;
CustomLayer(const CustomLayer&) = delete;
};
template <>
bool Layer::is<CustomLayer>() const;
} // namespace style
} // namespace mbgl
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