#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#ifdef __APPLE__
#include <OpenCL/opencl.h>
#else
#include <CL/cl.h>
#endif

#define KERNEL "part4.cl"

int main() {

	cl_platform_id platform; cl_device_id device; cl_context context;
	cl_program program; cl_kernel kernel; cl_command_queue queue;
	cl_mem kernelBuffer;

	FILE* programHandle; char *programBuffer; char *programLog;
	size_t programSize; char hostBuffer[32];

	// get first available sdk and gpu and create context
	clGetPlatformIDs(1, &platform, NULL);
	clGetDeviceIDs(platform, CL_DEVICE_TYPE_GPU, 1, &device, NULL);
	context = clCreateContext(NULL, 1, &device, NULL, NULL, NULL);

	// get size of kernel source
	programHandle = fopen(KERNEL, "r");
	fseek(programHandle, 0, SEEK_END);
	programSize = ftell(programHandle);
	rewind(programHandle);

	// read kernel source into buffer
	programBuffer = (char*) malloc(programSize + 1);
	programBuffer[programSize] = '\0';
	assert (programSize == fread(programBuffer, sizeof(char), programSize, programHandle));

	fclose(programHandle);

	// create and build program
	program = clCreateProgramWithSource(context, 1,
			(const char**) &programBuffer, &programSize, NULL);
	free(programBuffer);
	clBuildProgram(program, 1, &device, "-Werror -cl-std=CL1.1", NULL, NULL);

	// create kernel and command queue
	kernel = clCreateKernel(program, "hello", NULL);
	queue = clCreateCommandQueue(context, device, 0, NULL);

	// create kernel argument buffer and set it into kernel
	kernelBuffer = clCreateBuffer(context, CL_MEM_WRITE_ONLY,
			32 * sizeof(char), NULL, NULL);
	clSetKernelArg(kernel, 0, sizeof(cl_mem), &kernelBuffer);

	// execute kernel, read back the output and print to screen
	clEnqueueTask(queue, kernel, 0, NULL, NULL);
	clEnqueueReadBuffer(queue, kernelBuffer, CL_TRUE, 0,
			32 * sizeof(char), hostBuffer, 0, NULL, NULL);
	puts(hostBuffer);

	clFlush(queue);
	clFinish(queue);
	clReleaseKernel(kernel);
	clReleaseProgram(program);
	clReleaseMemObject(kernelBuffer);
	clReleaseCommandQueue(queue);
	clReleaseContext(context);

	return 0;

}

// vim: set ft=c ts=4 sw=4: