scummvm/backends/graphics/opengl/pipelines/pipeline.h
2016-03-16 20:29:30 +01:00

121 lines
3.3 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_PIPELINES_PIPELINE_H
#define BACKENDS_GRAPHICS_OPENGL_PIPELINES_PIPELINE_H
#include "backends/graphics/opengl/opengl-sys.h"
#include "backends/graphics/opengl/texture.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;
/**
* Draw a texture rectangle to the currently active framebuffer.
*
* @param texture Texture to use for drawing.
* @param coordinates x1, y1, x2, y2 coordinates where to draw the texture.
*/
virtual void drawTexture(const GLTexture &texture, const GLfloat *coordinates) = 0;
void drawTexture(const GLTexture &texture, GLfloat x, GLfloat y, GLfloat w, GLfloat h) {
const GLfloat coordinates[4*2] = {
x, y,
x + w, y,
x, y + h,
x + w, y + h
};
drawTexture(texture, coordinates);
}
/**
* 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;
};
} // End of namespace OpenGL
#endif