codebase / stimlib

  #ifndef RTS_GL_BIND_H
  #define RTS_GL_BIND_H
  
  #include <GL/glew.h>
  #include <GL/gl.h>
  
  #include <stdio.h>
  #include <cstring>
  

  //#include <cudaHandleError.h>

  #include "cuda_gl_interop.h"

  #include <stim/gl/error.h>

  namespace stim
  {

  static void InitGLEW()

  {
  	//Initialize the GLEW toolkit
  
  	GLenum err = glewInit();
  	if(GLEW_OK != err)
  	{
  		printf("Error starting GLEW.");
  	}
  	fprintf(stdout, "Status: Using GLEW %s\n", glewGetString(GLEW_VERSION));
  }
  

  static void cudaSetDevice(int major = 1, int minor = 3)

  {
  	cudaDeviceProp prop;
  	int dev;
  
  	//find a CUDA device that can handle an offscreen buffer
  	int num_gpu;
  	HANDLE_ERROR(cudaGetDeviceCount(&num_gpu));
  	printf("Number of CUDA devices detected: %d\n", num_gpu);
  	memset(&prop, 0, sizeof(cudaDeviceProp));
  	prop.major=major;
  	prop.minor=minor;
  	HANDLE_ERROR(cudaChooseDevice(&dev, &prop));
  	HANDLE_ERROR(cudaGetDeviceProperties(&prop, dev));
  	HANDLE_ERROR(cudaGLSetGLDevice(dev));
  }
  

  static void* cudaMapResource(cudaGraphicsResource* cudaBufferResource)

  {
  	//this function takes a predefined CUDA resource and maps it to a pointer
  	void* buffer;
  	HANDLE_ERROR(cudaGraphicsMapResources(1, &cudaBufferResource, NULL));
  	size_t size;
  	HANDLE_ERROR(cudaGraphicsResourceGetMappedPointer( (void**)&buffer, &size, cudaBufferResource));
  	return buffer;
  }

  static void cudaUnmapResource(cudaGraphicsResource* resource)

  {
  	//this function unmaps the CUDA resource so it can be used by OpenGL
  	HANDLE_ERROR(cudaGraphicsUnmapResources(1, &resource, NULL));
  }
  

  static void cudaCreateRenderBuffer(GLuint &glBufferName, cudaGraphicsResource* &cudaBufferResource, int resX, int resY)

  {
  	//delete the previous buffer name and resource
  	if(cudaBufferResource != 0)
  		HANDLE_ERROR(cudaGraphicsUnregisterResource(cudaBufferResource));
  	if(glBufferName != 0)
  		glDeleteBuffers(1, &glBufferName);
  
  	//generate an OpenGL offscreen buffer
  	glGenBuffers(1, &glBufferName);
  
  	//bind the buffer - directs all calls to this buffer
  	glBindBuffer(GL_PIXEL_UNPACK_BUFFER, glBufferName);
  	glBufferData(GL_PIXEL_UNPACK_BUFFER, resX * resY * sizeof(uchar3), NULL, GL_DYNAMIC_DRAW_ARB);
  	CHECK_OPENGL_ERROR
  	HANDLE_ERROR(cudaGraphicsGLRegisterBuffer(&cudaBufferResource, glBufferName, cudaGraphicsMapFlagsNone));
  }

  }

  #endif