/* Copyright (c) 2021, NVIDIA CORPORATION. All rights reserved.
 *
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 * modification, are permitted provided that the following conditions
 * are met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *  * Neither the name of NVIDIA CORPORATION nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
  3D texture sample

  This sample loads a 3D volume from disk and displays slices through it
  using 3D texture lookups.
*/

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <helper_gl.h>

#if defined(__APPLE__) || defined(MACOSX)
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
#include <GLUT/glut.h>
#ifndef glutCloseFunc
#define glutCloseFunc glutWMCloseFunc
#endif
#else
#include <GL/freeglut.h>
#endif

// includes, cuda
#include <vector_types.h>
#include <cuda_runtime.h>
#include <cuda_gl_interop.h>

// CUDA utilities and system includes
#include <helper_cuda.h>
#include <helper_functions.h>
#include <vector_types.h>

typedef unsigned int uint;
typedef unsigned char uchar;

#define MAX_EPSILON_ERROR 5.0f
#define THRESHOLD 0.15f

const char *sSDKsample = "simpleTexture3D";

const char *volumeFilename = "Bucky.raw";
const cudaExtent volumeSize = make_cudaExtent(32, 32, 32);

const uint width = 512, height = 512;
const dim3 blockSize(16, 16, 1);
const dim3 gridSize(width / blockSize.x, height / blockSize.y);

float w = 0.5;  // texture coordinate in z

GLuint pbo;  // OpenGL pixel buffer object
struct cudaGraphicsResource
    *cuda_pbo_resource;  // CUDA Graphics Resource (to transfer PBO)

bool linearFiltering = true;
bool animate = true;

StopWatchInterface *timer = NULL;

uint *d_output = NULL;

// Auto-Verification Code
const int frameCheckNumber = 4;
int fpsCount = 0;  // FPS count for averaging
int fpsLimit = 1;  // FPS limit for sampling
int g_Index = 0;
unsigned int frameCount = 0;
unsigned int g_TotalErrors = 0;
volatile int g_GraphicsMapFlag = 0;

int *pArgc = NULL;
char **pArgv = NULL;

#ifndef MAX
#define MAX(a, b) ((a > b) ? a : b)
#endif

extern "C" void cleanup();
extern "C" void setTextureFilterMode(bool bLinearFilter);
extern "C" void initCuda(const uchar *h_volume, cudaExtent volumeSize);
extern "C" void render_kernel(dim3 gridSize, dim3 blockSize, uint *d_output,
                              uint imageW, uint imageH, float w);
extern void cleanupCuda();

void loadVolumeData(char *exec_path);

void computeFPS() {
  frameCount++;
  fpsCount++;

  if (fpsCount == fpsLimit) {
    char fps[256];
    float ifps = 1.f / (sdkGetAverageTimerValue(&timer) / 1000.f);
    sprintf(fps, "%s: %3.1f fps", sSDKsample, ifps);

    glutSetWindowTitle(fps);
    fpsCount = 0;

    fpsLimit = ftoi(MAX(1.0f, ifps));
    sdkResetTimer(&timer);
  }
}

// render image using CUDA
void render() {
  // map PBO to get CUDA device pointer
  g_GraphicsMapFlag++;
  checkCudaErrors(cudaGraphicsMapResources(1, &cuda_pbo_resource, 0));
  size_t num_bytes;
  checkCudaErrors(cudaGraphicsResourceGetMappedPointer(
      (void **)&d_output, &num_bytes, cuda_pbo_resource));
  // printf("CUDA mapped PBO: May access %ld bytes\n", num_bytes);

  // call CUDA kernel, writing results to PBO
  render_kernel(gridSize, blockSize, d_output, width, height, w);

  getLastCudaError("render_kernel failed");

  if (g_GraphicsMapFlag) {
    checkCudaErrors(cudaGraphicsUnmapResources(1, &cuda_pbo_resource, 0));
    g_GraphicsMapFlag--;
  }
}

// display results using OpenGL (called by GLUT)
void display() {
  sdkStartTimer(&timer);

  render();

  // display results
  glClear(GL_COLOR_BUFFER_BIT);

  // draw image from PBO
  glDisable(GL_DEPTH_TEST);
  glRasterPos2i(0, 0);
  glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
  glDrawPixels(width, height, GL_RGBA, GL_UNSIGNED_BYTE, 0);
  glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);

  glutSwapBuffers();
  glutReportErrors();

  sdkStopTimer(&timer);
  computeFPS();
}

void idle() {
  if (animate) {
    w += 0.01f;
    glutPostRedisplay();
  }
}

void keyboard(unsigned char key, int x, int y) {
  switch (key) {
    case 27:
#if defined(__APPLE__) || defined(MACOSX)
      exit(EXIT_SUCCESS);
      glutDestroyWindow(glutGetWindow());
      return;
#else
      glutDestroyWindow(glutGetWindow());
      return;
#endif

    case '=':
    case '+':
      w += 0.01f;
      break;

    case '-':
      w -= 0.01f;
      break;

    case 'f':
      linearFiltering = !linearFiltering;
      setTextureFilterMode(linearFiltering);
      break;

    case ' ':
      animate = !animate;
      break;

    default:
      break;
  }

  glutPostRedisplay();
}

void reshape(int x, int y) {
  glViewport(0, 0, x, y);

  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();

  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
}

void cleanup() {
  sdkDeleteTimer(&timer);

  // add extra check to unmap the resource before unregistering it
  if (g_GraphicsMapFlag) {
    checkCudaErrors(cudaGraphicsUnmapResources(1, &cuda_pbo_resource, 0));
    g_GraphicsMapFlag--;
  }

  // unregister this buffer object from CUDA C
  checkCudaErrors(cudaGraphicsUnregisterResource(cuda_pbo_resource));
  glDeleteBuffers(1, &pbo);
  cleanupCuda();
}

void initGLBuffers() {
  // create pixel buffer object
  glGenBuffers(1, &pbo);
  glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
  glBufferData(GL_PIXEL_UNPACK_BUFFER_ARB, width * height * sizeof(GLubyte) * 4,
               0, GL_STREAM_DRAW_ARB);
  glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);

  // register this buffer object with CUDA
  checkCudaErrors(cudaGraphicsGLRegisterBuffer(
      &cuda_pbo_resource, pbo, cudaGraphicsMapFlagsWriteDiscard));
}

// Load raw data from disk
uchar *loadRawFile(const char *filename, size_t size) {
  FILE *fp = fopen(filename, "rb");

  if (!fp) {
    fprintf(stderr, "Error opening file '%s'\n", filename);
    return 0;
  }

  uchar *data = (uchar *)malloc(size);
  size_t read = fread(data, 1, size, fp);
  fclose(fp);

  printf("Read '%s', %zu bytes\n", filename, read);

  return data;
}

void initGL(int *argc, char **argv) {
  // initialize GLUT callback functions
  glutInit(argc, argv);
  glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
  glutInitWindowSize(width, height);
  glutCreateWindow("CUDA 3D texture");
  glutDisplayFunc(display);
  glutKeyboardFunc(keyboard);
  glutReshapeFunc(reshape);
  glutIdleFunc(idle);

  if (!isGLVersionSupported(2, 0) ||
      !areGLExtensionsSupported("GL_ARB_pixel_buffer_object")) {
    fprintf(stderr, "Required OpenGL extensions are missing.");
    exit(EXIT_FAILURE);
  }
}

void runAutoTest(const char *ref_file, char *exec_path) {
  checkCudaErrors(
      cudaMalloc((void **)&d_output, width * height * sizeof(GLubyte) * 4));

  // render the volumeData
  render_kernel(gridSize, blockSize, d_output, width, height, w);

  checkCudaErrors(cudaDeviceSynchronize());
  getLastCudaError("render_kernel failed");

  void *h_output = malloc(width * height * sizeof(GLubyte) * 4);
  checkCudaErrors(cudaMemcpy(h_output, d_output,
                             width * height * sizeof(GLubyte) * 4,
                             cudaMemcpyDeviceToHost));
  sdkDumpBin(h_output, width * height * sizeof(GLubyte) * 4,
             "simpleTexture3D.bin");

  bool bTestResult = sdkCompareBin2BinFloat(
      "simpleTexture3D.bin", sdkFindFilePath(ref_file, exec_path),
      width * height, MAX_EPSILON_ERROR, THRESHOLD, exec_path);

  checkCudaErrors(cudaFree(d_output));
  free(h_output);

  sdkStopTimer(&timer);
  sdkDeleteTimer(&timer);

  exit(bTestResult ? EXIT_SUCCESS : EXIT_FAILURE);
}

void loadVolumeData(char *exec_path) {
  // load volume data
  const char *path = sdkFindFilePath(volumeFilename, exec_path);

  if (path == NULL) {
    fprintf(stderr, "Error unable to find 3D Volume file: '%s'\n",
            volumeFilename);
    exit(EXIT_FAILURE);
  }

  size_t size = volumeSize.width * volumeSize.height * volumeSize.depth;
  uchar *h_volume = loadRawFile(path, size);

  initCuda(h_volume, volumeSize);
  sdkCreateTimer(&timer);

  free(h_volume);
}

////////////////////////////////////////////////////////////////////////////////
// Program main
////////////////////////////////////////////////////////////////////////////////
int main(int argc, char **argv) {
  pArgc = &argc;
  pArgv = argv;

  char *ref_file = NULL;

#if defined(__linux__)
  setenv("DISPLAY", ":0", 0);
#endif

  printf("%s Starting...\n\n", sSDKsample);

  if (checkCmdLineFlag(argc, (const char **)argv, "file")) {
    fpsLimit = frameCheckNumber;
    getCmdLineArgumentString(argc, (const char **)argv, "file", &ref_file);
  }

  // use command-line specified CUDA device, otherwise use device with highest
  // Gflops/s
  findCudaDevice(argc, (const char **)argv);

  if (ref_file) {
    loadVolumeData(argv[0]);
    runAutoTest(ref_file, argv[0]);
  } else {
    initGL(&argc, argv);

    // OpenGL buffers
    initGLBuffers();

    loadVolumeData(argv[0]);
  }

  printf(
      "Press space to toggle animation\n"
      "Press '+' and '-' to change displayed slice\n");

#if defined(__APPLE__) || defined(MACOSX)
  atexit(cleanup);
#else
  glutCloseFunc(cleanup);
#endif

  glutMainLoop();

  exit(EXIT_SUCCESS);
}
