/* Copyright (c) 2021, NVIDIA CORPORATION. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * 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
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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 */

/*
  Bindless Texture/Surface

  This sample generates a few 2D textures and uses cudaTextureObjects to
  perform pseudo virtual texturing for display. One 2D texture stores
  references to other textures.
  Furthermore use of mip mapping is shown using both cudaTextureObjects
  and cudaSurfaceObjects.

  Look into the bindlessTexture_kernel.cu file for most relevant code.
*/

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

#include <vector>

#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

#include "bindlessTexture.h"

#include <helper_functions.h>
#include <cuda_gl_interop.h>

#define MAX_EPSILON_ERROR 5.0f
#define THRESHOLD 0.15f

const char *sSDKsample = "CUDA bindlessTexture";

const char *imageFilenames[] = {
    "flower.ppm", "person.ppm", "sponge.ppm",
};

const cudaExtent atlasSize = make_cudaExtent(4, 4, 0);
const dim3 windowSize(512, 512);
const dim3 windowBlockSize(16, 16, 1);
const dim3 windowGridSize(windowSize.x / windowBlockSize.x,
                          windowSize.y / windowBlockSize.y);

float lod = 0.5;  // texture mip map level

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

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;

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

extern "C" void initAtlasAndImages(const Image *images, size_t numImages,
                                   cudaExtent atlasSize);
extern "C" void deinitAtlasAndImages();
extern "C" void randomizeAtlas();
extern "C" void renderAtlasImage(dim3 gridSize, dim3 blockSize, uint *d_output,
                                 uint imageW, uint imageH, float lod);

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

// render image using CUDA
void render() {
  // map PBO to get CUDA device pointer
  checkCudaErrors(cudaGraphicsMapResources(1, &cuda_pbo_resource, 0));
  size_t num_bytes;
  checkCudaErrors(cudaGraphicsResourceGetMappedPointer(
      (void **)&d_output, &num_bytes, cuda_pbo_resource));

  // call CUDA kernel, writing results to PBO
  renderAtlasImage(windowGridSize, windowBlockSize, d_output, windowSize.x,
                   windowSize.y, lod);

  getLastCudaError("render_kernel failed");

  checkCudaErrors(cudaGraphicsUnmapResources(1, &cuda_pbo_resource, 0));
}

// 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(windowSize.x, windowSize.y, GL_RGBA, GL_UNSIGNED_BYTE, 0);
  glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);

  glutSwapBuffers();
  glutReportErrors();

  sdkStopTimer(&timer);
  computeFPS();
}

void idle() {
  if (animate) {
    lod += 0.02f;
    glutPostRedisplay();
  }
}

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

    case '=':
    case '+':
      lod += 0.25f;
      break;

    case '-':
      lod -= 0.25f;
      break;

    case 'r':
      randomizeAtlas();
      break;

    case ' ':
      animate = !animate;
      lod = 0.0f;
      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);
}

// Global cleanup function
// Shared by both GL and non-GL code paths
void cleanup() {
  sdkDeleteTimer(&timer);

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

void cleanup_all() {
  cleanup();
  deinitAtlasAndImages();
}

void initGLBuffers() {
  // create pixel buffer object
  glGenBuffers(1, &pbo);
  glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
  glBufferData(GL_PIXEL_UNPACK_BUFFER_ARB,
               windowSize.x * windowSize.y * 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(windowSize.x, windowSize.y);
  glutCreateWindow(sSDKsample);
  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) {
  size_t windowBytes = windowSize.x * windowSize.y * sizeof(GLubyte) * 4;

  checkCudaErrors(cudaMalloc((void **)&d_output, windowBytes));

  // render the volumeData
  renderAtlasImage(windowGridSize, windowBlockSize, d_output, windowSize.x,
                   windowSize.y, lod);

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

  void *h_output = malloc(windowBytes);
  checkCudaErrors(
      cudaMemcpy(h_output, d_output, windowBytes, cudaMemcpyDeviceToHost));
  sdkDumpBin(h_output, (unsigned int)windowBytes, "bindlessTexture.bin");

  bool bTestResult = sdkCompareBin2BinFloat(
      "bindlessTexture.bin", sdkFindFilePath(ref_file, exec_path),
      windowSize.x * windowSize.y, MAX_EPSILON_ERROR, THRESHOLD, exec_path);

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

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

  exit(bTestResult ? EXIT_SUCCESS : EXIT_FAILURE);
}

void loadImageData(const char *exe_path) {
  std::vector<Image> images;

  for (size_t i = 0; i < sizeof(imageFilenames) / sizeof(imageFilenames[0]);
       i++) {
    unsigned int imgWidth = 0;
    unsigned int imgHeight = 0;
    uchar *imgData = NULL;
    const char *imgPath = 0;
    const char *imgFilename = imageFilenames[i];

    if (exe_path) {
      imgPath = sdkFindFilePath(imgFilename, exe_path);
    }

    if (imgPath == 0) {
      printf("Error finding image file '%s'\n", imgFilename);
      exit(EXIT_FAILURE);
    }

    sdkLoadPPM4(imgPath, (unsigned char **)&imgData, &imgWidth, &imgHeight);

    if (!imgData) {
      printf("Error opening file '%s'\n", imgPath);
      exit(EXIT_FAILURE);
    }

    printf("Loaded '%s', %d x %d pixels\n", imgPath, imgWidth, imgHeight);

    checkHost(imgWidth > 1);
    checkHost(imgHeight > 1);

    Image img;
    img.size = make_cudaExtent(imgWidth, imgHeight, 0);
    img.h_data = imgData;
    images.push_back(img);
  }

  initAtlasAndImages(&images[0], images.size(), atlasSize);
}

////////////////////////////////////////////////////////////////////////////////
// Program main
////////////////////////////////////////////////////////////////////////////////
int main(int argc, char **argv) {
  sdkCreateTimer(&timer);

  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);
  }

  srand(15234);

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

  if (!ref_file) {
    initGL(&argc, argv);

    // OpenGL buffers
    initGLBuffers();
  }

  if (!checkCudaCapabilities(3, 0)) {
    cleanup();

    exit(EXIT_WAIVED);
  }

  loadImageData(argv[0]);

  if (ref_file) {
    runAutoTest(ref_file, argv[0]);
  }

  printf(
      "Press space to toggle animation\n"
      "Press '+' and '-' to change lod level\n"
      "Press 'r' to randomize virtual atlas\n");

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

  glutMainLoop();
}