scummvm/backends/graphics3d/opengl/surfacerenderer.h
2022-06-26 18:32:10 +02:00

122 lines
3.0 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef BACKENDS_GRAPHICS3D_OPENGL_SURFACE_RENDERER_H
#define BACKENDS_GRAPHICS3D_OPENGL_SURFACE_RENDERER_H
#include "math/rect2d.h"
#include "graphics/opengl/system_headers.h"
namespace OpenGL {
class Shader;
class TextureGL;
/**
* A renderer to draw textures as two dimensional surfaces to the screen.
*/
class SurfaceRenderer {
public:
SurfaceRenderer();
virtual ~SurfaceRenderer();
/**
* Push the current OpenGL state, and set up the adequate state for calling the render method.
*/
virtual void prepareState() = 0;
/**
* Draw a 2D surface from the specified texture.
*
* The destination rectangle must be specified in the following coordinates system:
* x: left [0.0, 1.0] right
* y: top [0.0, 1.0] bottom
*
*/
virtual void render(const TextureGL *tex, const Math::Rect2d &dest) = 0;
/**
* Pop the OpenGL state to restore it as it was before calling the prepareState method.
*/
virtual void restorePreviousState() = 0;
/**
* Invert the surface along the Y coordinate
*
* Causes the image to be drawn upside down
*/
void setFlipY(bool flipY);
/**
* Set the alpha blending with already drawn content
*/
void enableAlphaBlending(bool enable);
protected:
bool _flipY;
bool _alphaBlending;
};
#if defined(USE_OPENGL_GAME)
class FixedSurfaceRenderer : public SurfaceRenderer {
public:
virtual ~FixedSurfaceRenderer();
// SurfaceRenderer API
void prepareState() override;
void render(const TextureGL *tex, const Math::Rect2d &dest) override;
void restorePreviousState() override;
};
#endif
#if defined(USE_OPENGL_SHADERS)
class ShaderSurfaceRenderer : public SurfaceRenderer {
public:
ShaderSurfaceRenderer();
virtual ~ShaderSurfaceRenderer();
// SurfaceRenderer API
void prepareState() override;
void render(const TextureGL *tex, const Math::Rect2d &dest) override;
void restorePreviousState() override;
private:
Shader *_boxShader;
GLuint _boxVerticesVBO;
GLboolean _prevStateDepthTest;
GLboolean _prevStateDepthWriteMask;
GLboolean _prevStateBlend;
GLint _prevStateBlendFunc;
GLint _prevStateViewport[4];
};
#endif
SurfaceRenderer *createBestSurfaceRenderer();
} // End of namespace OpenGL
#endif // GRAPHICS_OPENGL_SURFACE_RENDERER_H