scummvm/backends/graphics/opengl/pipeline.h
2016-03-16 20:29:27 +01:00

144 lines
3.8 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 2
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#ifndef BACKENDS_GRAPHICS_OPENGL_PIEPLINE_H
#define BACKENDS_GRAPHICS_OPENGL_PIEPLINE_H
#include "backends/graphics/opengl/opengl-sys.h"
namespace OpenGL {
class Framebuffer;
#if !USE_FORCED_GLES
class Shader;
#endif
/**
* Interface for OpenGL pipeline functionality.
*
* This encapsulates differences in various rendering pipelines used for
* OpenGL, OpenGL ES 1, and OpenGL ES 2.
*/
class Pipeline {
public:
Pipeline();
virtual ~Pipeline() {}
/**
* Activate the pipeline.
*
* This sets the OpenGL state to make use of drawing with the given
* OpenGL pipeline.
*/
virtual void activate() = 0;
/**
* Set framebuffer to render to.
*
* Client is responsible for any memory management related to framebuffer.
*
* @param framebuffer Framebuffer to activate.
* @return Formerly active framebuffer.
*/
Framebuffer *setFramebuffer(Framebuffer *framebuffer);
#if !USE_FORCED_GLES
/**
* Set shader program.
*
* Not all pipelines support shader programs. This is method exits at this
* place for convenience only.
*
* Client is responsible for any memory management related to shader.
*
* @param shader Shader program to activate.
* @return Formerly active shader program.
*/
virtual Shader *setShader(Shader *shader) { return nullptr; }
#endif
/**
* Set modulation color.
*
* @param r Red component in [0,1].
* @param g Green component in [0,1].
* @param b Blue component in [0,1].
* @param a Alpha component in [0,1].
*/
virtual void setColor(GLfloat r, GLfloat g, GLfloat b, GLfloat a) = 0;
/**
* Setup coordinates for drawing with glDrawArrays.
*
* @param vertices The list of vertices, 2 coordinates for each vertex.
* @param texCoords The list of texture coordinates, 2 coordinates for
* each vertex.
*/
virtual void setDrawCoordinates(const GLfloat *vertices, const GLfloat *texCoords) = 0;
/**
* Set the projection matrix.
*
* This is intended to be only ever be used by Framebuffer subclasses.
*/
virtual void setProjectionMatrix(const GLfloat *projectionMatrix) = 0;
protected:
Framebuffer *_activeFramebuffer;
};
#if !USE_FORCED_GLES2
class FixedPipeline : public Pipeline {
public:
virtual void activate();
virtual void setColor(GLfloat r, GLfloat g, GLfloat b, GLfloat a);
virtual void setDrawCoordinates(const GLfloat *vertices, const GLfloat *texCoords);
virtual void setProjectionMatrix(const GLfloat *projectionMatrix);
};
#endif // !USE_FORCED_GLES2
#if !USE_FORCED_GLES
class ShaderPipeline : public Pipeline {
public:
ShaderPipeline();
virtual void activate();
virtual Shader *setShader(Shader *shader);
virtual void setColor(GLfloat r, GLfloat g, GLfloat b, GLfloat a);
virtual void setDrawCoordinates(const GLfloat *vertices, const GLfloat *texCoords);
virtual void setProjectionMatrix(const GLfloat *projectionMatrix);
private:
Shader *_activeShader;
};
#endif // !USE_FORCED_GLES
} // End of namespace OpenGL
#endif