framebuffer.h

/* 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_GRAPHICS_OPENGL_FRAMEBUFFER_H
#define BACKENDS_GRAPHICS_OPENGL_FRAMEBUFFER_H
 
#include "graphics/opengl/system_headers.h"
 
#include "math/matrix4.h"
 
#include "common/rotationmode.h"
 
namespace OpenGL {
 
class Pipeline;
 
class Framebuffer {
public:
    Framebuffer();
    virtual ~Framebuffer() {};
 
public:
    enum BlendMode {
        kBlendModeDisabled,
 
        kBlendModeOpaque,
 
        kBlendModeTraditionalTransparency,
 
        kBlendModePremultipliedTransparency,
 
        kBlendModeAdditive,
 
        kBlendModeMaskAlphaAndInvertByColor,
    };
 
    void setClearColor(GLfloat r, GLfloat g, GLfloat b, GLfloat a);
 
    void enableBlend(BlendMode mode);
 
    void enableScissorTest(bool enable);
 
    void setScissorBox(GLint x, GLint y, GLsizei w, GLsizei h);
 
    const Math::Matrix4 &getProjectionMatrix() const { return _projectionMatrix; }
 
    enum CopyMask {
        kCopyMaskClearColor   = (1 << 0),
        kCopyMaskBlendState   = (1 << 1),
        kCopyMaskScissorState = (1 << 2),
        kCopyMaskScissorBox   = (1 << 4),
 
        kCopyMaskAll          = kCopyMaskClearColor | kCopyMaskBlendState |
                                kCopyMaskScissorState | kCopyMaskScissorBox,
    };
 
    void copyRenderStateFrom(const Framebuffer &other, uint copyMask);
 
protected:
    bool isActive() const { return _pipeline != nullptr; }
 
    GLint _viewport[4];
    void applyViewport();
 
    Math::Matrix4 _projectionMatrix;
    void applyProjectionMatrix();
 
    virtual void activateInternal() = 0;
 
    virtual void deactivateInternal() {}
 
public:
    virtual bool setSize(uint width, uint height) = 0;
 
    void activate(Pipeline *pipeline);
 
    void deactivate();
 
private:
    Pipeline *_pipeline;
 
    GLfloat _clearColor[4];
    void applyClearColor();
 
    BlendMode _blendState;
    void applyBlendState();
 
    bool _scissorTestState;
    void applyScissorTestState();
 
    GLint _scissorBox[4];
    void applyScissorBox();
};
 
class Backbuffer : public Framebuffer {
public:
    bool setSize(uint width, uint height) override;
 
protected:
    void activateInternal() override;
};
 
#if !USE_FORCED_GLES
class Texture;
 
class TextureTarget : public Framebuffer {
public:
    TextureTarget();
    ~TextureTarget() override;
 
    void destroy();
 
    void create();
 
    bool setSize(uint width, uint height) override;
 
    Texture *getTexture() const { return _texture; }
 
protected:
    void activateInternal() override;
 
private:
    Texture *_texture;
    GLuint _glFBO;
    bool _needUpdate;
};
#endif
 
} // End of namespace OpenGL
 
#endif