src/dawn/native/opengl/DisplayEGL.h

// Copyright 2024 The Dawn & Tint Authors
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#ifndef SRC_DAWN_NATIVE_OPENGL_DISPLAYEGL_H_
#define SRC_DAWN_NATIVE_OPENGL_DISPLAYEGL_H_

#include <memory>

#include "absl/types/span.h"  // TODO(343500108): Use std::span when we have C++20.
#include "dawn/common/DynamicLib.h"
#include "dawn/common/NonMovable.h"
#include "dawn/common/egl_platform.h"
#include "dawn/native/opengl/EGLFunctions.h"

namespace dawn::native::opengl {

static constexpr EGLConfig kNoConfig = 0;

// Represents a connection to an EGL driver, with its EGLDisplay, its functions and other metadata
// global to EGL.
class DisplayEGL : NonMovable {
  public:
    static ResultOrError<std::unique_ptr<DisplayEGL>> CreateFromDynamicLoading(
        wgpu::BackendType backend,
        const char* libName);

    static ResultOrError<std::unique_ptr<DisplayEGL>>
    CreateFromProcAndDisplay(wgpu::BackendType backend, EGLGetProcProc getProc, EGLDisplay display);

    explicit DisplayEGL(wgpu::BackendType backend);
    ~DisplayEGL();

    // A convenience ref to avoid having to call an accessor function every time we need to use EGL
    const EGLFunctions& egl;
    EGLDisplay GetDisplay() const;
    EGLint GetAPIEnum() const;
    EGLint GetAPIBit() const;

    absl::Span<const wgpu::TextureFormat> GetPotentialSurfaceFormats() const;

    // Chooses an EGLConfig that works for that surface type and color format.
    EGLConfig ChooseConfig(EGLint surfaceType,
                           wgpu::TextureFormat color,
                           wgpu::TextureFormat depthStencil = wgpu::TextureFormat::Undefined) const;

  private:
    MaybeError InitializeWithDynamicLoading(const char* libName);
    MaybeError InitializeWithProcAndDisplay(EGLGetProcProc getProc, EGLDisplay display);

    DynamicLib mLib;

    EGLFunctions mFunctions;
    EGLDisplay mDisplay = EGL_NO_DISPLAY;

    EGLint mApiEnum;
    EGLint mApiBit;
    // Different from mApiBit because renderables don't make a difference between GLES 2 and 3
    EGLint mRenderableBit;
};

}  // namespace dawn::native::opengl

#endif  // SRC_DAWN_NATIVE_OPENGL_DISPLAYEGL_H_