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OpenSpace/modules/globebrowsing/other/pixelbuffer.h
Alexander Bock 0e9edaeb12 Fix byte order mark commits
Update Ghoul
2017-07-17 15:54:00 -04:00

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/*****************************************************************************************
* *
* OpenSpace *
* *
* Copyright (c) 2014-2017 *
* *
* Permission is hereby granted, free of charge, to any person obtaining a copy of this *
* software and associated documentation files (the "Software"), to deal in the Software *
* without restriction, including without limitation the rights to use, copy, modify, *
* merge, publish, distribute, sublicense, and/or sell copies of the Software, and to *
* permit persons to whom the Software is furnished to do so, subject to the following *
* conditions: *
* *
* The above copyright notice and this permission notice shall be included in all copies *
* or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, *
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A *
* PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT *
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF *
* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE *
* OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
****************************************************************************************/
#ifndef __OPENSPACE_MODULE_GLOBEBROWSING___PIXEL_BUFFER___H__
#define __OPENSPACE_MODULE_GLOBEBROWSING___PIXEL_BUFFER___H__
#include <ghoul/opengl/ghoul_gl.h>
namespace openspace::globebrowsing {
/**
* Handles an OpenGL pixel buffer which contains data allocated on the GPU. A simple
* class that wraps the standard functionality of OpenGL pixel buffer objects. Once
* the PixelBuffer is created, data is allocated on the GPU. When mapping data to a
* address pointer, the user needs to ensure the data is unmapped before the data can
* be used on the GPU / CPU depending on Usage.
*/
class PixelBuffer {
public:
/**
* All kinds of usage for pixel buffer objects as defined by the OpenGL standard.
* See: https://www.khronos.org/registry/OpenGL-Refpages/gl4/html/glBufferData.xhtml
*/
enum class Usage : std::underlying_type_t<GLenum> {
StreamDraw = static_cast<std::underlying_type_t<GLenum>>(GL_STREAM_DRAW),
StreamRead = static_cast<std::underlying_type_t<GLenum>>(GL_STREAM_READ),
StreamCopy = static_cast<std::underlying_type_t<GLenum>>(GL_STREAM_COPY),
StaticDraw = static_cast<std::underlying_type_t<GLenum>>(GL_STATIC_DRAW),
StaticRead = static_cast<std::underlying_type_t<GLenum>>(GL_STATIC_READ),
StaticCopy = static_cast<std::underlying_type_t<GLenum>>(GL_STATIC_COPY),
DynamicDraw = static_cast<std::underlying_type_t<GLenum>>(GL_DYNAMIC_DRAW),
DynamicRead = static_cast<std::underlying_type_t<GLenum>>(GL_DYNAMIC_READ),
DynamicCopy = static_cast<std::underlying_type_t<GLenum>>(GL_DYNAMIC_COPY)
};
/**
* Access hints for OpenGL buffer mapping
* See: https://www.khronos.org/registry/OpenGL-Refpages/gl2.1/xhtml/glMapBuffer.xml
*/
enum class Access : std::underlying_type_t<GLenum> {
ReadOnly = static_cast<std::underlying_type_t<GLenum>>(GL_READ_ONLY),
WriteOnly = static_cast<std::underlying_type_t<GLenum>>(GL_WRITE_ONLY),
ReadWrite = static_cast<std::underlying_type_t<GLenum>>(GL_READ_WRITE)
};
/**
* Allocates <code>numBytes</code> bytes on the GPU and creates an ID for the pixel
* buffer object.
* \param numBytes is the number of bytes to be allocated on GPU memory
* \param usage is the <code>Usage</code> for the pixel buffer
*/
PixelBuffer(size_t numBytes, Usage usage);
/**
* calls glDeleteBuffers().
*/
~PixelBuffer();
/**
* Maps an address pointer to GPU direct memory access. The user must make sure the
* buffer is bound before calling this function.
* \param access is the access to which can be any of <code>GL_READ_ONLY</code>,
* <code>GL_WRITE_ONLY</code>, or <code>GL_READ_WRITE</code>
* \returns the DMA address to the mapped buffer. Returns nullptr if the mapping
* failed
*/
void* mapBuffer(Access access);
/**
* Maps an address pointer to GPU direct memory access. Gives access to a range of
* the buffer. The user must make sure the buffer is bound before calling this
* function.
* \param offet is the number of bytes to the first address to get in the buffer
* \param length is the number of bytes to access in the buffer
* \param access is a bitfield describing the access as described in:
* https://www.khronos.org/registry/OpenGL-Refpages/gl4/html/glMapBufferRange.xhtml
* \returns the DMA address to the mapped buffer. Returns nullptr if the mapping
* failed
*/
void* mapBufferRange(GLintptr offset, GLsizeiptr length, BufferAccessMask access);
/**
* Maps the default buffer and makes the data available on the GPU
*/
bool unMapBuffer();
/**
* Calls glBindBuffer()
*/
void bind();
/**
* Calls glBindBuffer() with argument 0 to unmap any pixel buffer
*/
void unbind();
/**
* \returns true of the buffer is mapped, otherwise false
*/
bool isMapped() const;
/**
* \returns the OpenGL id of the pixel buffer object
*/
operator GLuint() const;
private:
GLuint _id;
const size_t _numBytes;
const Usage _usage;
bool _isMapped;
};
} // namespace openspace::globebrowsing
#endif // __OPENSPACE_MODULE_GLOBEBROWSING___PIXEL_BUFFER___H__