cuda-samples/Samples/postProcessGL/main.cpp

/* Copyright (c) 2021, NVIDIA CORPORATION. All rights reserved.
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 * modification, are permitted provided that the following conditions
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 *    notice, this list of conditions and the following disclaimer.
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 *    notice, this list of conditions and the following disclaimer in the
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/*
  This example demonstrates the use of CUDA/OpenGL interoperability
  to post-process an image of a 3D scene generated in OpenGL.

  The basic steps are:
  1 - render the scene to the framebuffer
  2 - map the color texture so that its memory is accessible from CUDA
  4 - run CUDA to process the image, writing to memory
      a- either mapped from a second PBO
      b- or allocated through CUDA
  6 - copy result
      a- from the PBO to a texture with glTexSubImage2D()
      b- or map the target texture and do a cuda memory copy
  7 - display the texture with a fullscreen quad

  The example also provides two solutions for the format of the image:
    - RGBA16F : more bytes involved but easier to handle because
      compatible with regular fragment shader
    - RGBA8UI : 32bytes, but the teapot color must be scaled by 255 (so we
      needed GLSL code)
  How about RGBA8?  The CUDA driver does not have consistent interoperability
  with this format.
  Older GPUs may not store data the same way compared with newer GPUs,
  resulting in a swap of R and B components
  On older HW, this will need workarounds.

  Press space to toggle the CUDA processing on/off.
  Press 'a' to toggle animation.
  Press '+' and '-' to increment and decrement blur radius
*/

// this mode is "old fashion" : use glTexSubImage2D() to update the final result
// commenting it will make the sample use the other way :
// map a texture in CUDA and blit the result into it
#define USE_TEXSUBIMAGE2D

#if defined(WIN32) || defined(_WIN32) || defined(WIN64) || defined(_WIN64)
#define WINDOWS_LEAN_AND_MEAN
#define NOMINMAX
#include <windows.h>
#pragma warning(disable : 4996)
#endif

// OpenGL Graphics includes
#include <helper_gl.h>
#if defined(__APPLE__) || defined(MACOSX)
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
#include <GLUT/glut.h>
// Sorry for Apple : unsigned int sampler is not available to you, yet...
// Let's switch to the use of PBO and glTexSubImage
#define USE_TEXSUBIMAGE2D
#else
#include <GL/freeglut.h>
#endif

// CUDA includes
#include <cuda_runtime.h>
#include <cuda_gl_interop.h>

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

#include <helper_functions.h>
#include <rendercheck_gl.h>

// Shared Library Test Functions
#define MAX_EPSILON 10
#define REFRESH_DELAY 10  // ms

const char *sSDKname = "postProcessGL";

unsigned int g_TotalErrors = 0;

// CheckFBO/BackBuffer class objects
CheckRender *g_CheckRender = NULL;

////////////////////////////////////////////////////////////////////////////////
// constants / global variables
unsigned int window_width = 512;
unsigned int window_height = 512;
unsigned int image_width = 512;
unsigned int image_height = 512;
int iGLUTWindowHandle = 0;  // handle to the GLUT window

// pbo and fbo variables
#ifdef USE_TEXSUBIMAGE2D
GLuint pbo_dest;
struct cudaGraphicsResource *cuda_pbo_dest_resource;
#else
unsigned int *cuda_dest_resource;
GLuint shDrawTex;  // draws a texture
struct cudaGraphicsResource *cuda_tex_result_resource;
#endif
extern cudaTextureObject_t inTexObject;

GLuint fbo_source;
struct cudaGraphicsResource *cuda_tex_screen_resource;

unsigned int size_tex_data;
unsigned int num_texels;
unsigned int num_values;

// (offscreen) render target fbo variables
GLuint framebuffer;     // to bind the proper targets
GLuint depth_buffer;    // for proper depth test while rendering the scene
GLuint tex_screen;      // where we render the image
GLuint tex_cudaResult;  // where we will copy the CUDA result

float rotate[3];

char *ref_file = NULL;
bool enable_cuda = true;
bool animate = true;
int blur_radius = 8;
int max_blur_radius = 16;

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

// Timer
static int fpsCount = 0;
static int fpsLimit = 1;
StopWatchInterface *timer = NULL;

#ifndef USE_TEXTURE_RGBA8UI
#pragma message("Note: Using Texture fmt GL_RGBA16F_ARB")
#else
// NOTE: the current issue with regular RGBA8 internal format of textures
// is that HW stores them as BGRA8. Therefore CUDA will see BGRA where users
// expected RGBA8. To prevent this issue, the driver team decided to prevent
// this to happen
// instead, use RGBA8UI which required the additional work of scaling the
// fragment shader
// output from 0-1 to 0-255. This is why we have some GLSL code, in this case
#pragma message("Note: Using Texture RGBA8UI + GLSL for teapot rendering")
#endif
GLuint shDrawPot;  // colors the teapot

////////////////////////////////////////////////////////////////////////////////
extern "C" void launch_cudaProcess(dim3 grid, dim3 block, int sbytes,
                                   cudaArray *g_data, unsigned int *g_odata,
                                   int imgw, int imgh, int tilew, int radius,
                                   float threshold, float highlight);

// Forward declarations
void runStdProgram(int argc, char **argv);
void FreeResource();
void Cleanup(int iExitCode);

// GL functionality
bool initGL(int *argc, char **argv);

#ifdef USE_TEXSUBIMAGE2D
void createPBO(GLuint *pbo, struct cudaGraphicsResource **pbo_resource);
void deletePBO(GLuint *pbo);
#endif

void createTextureDst(GLuint *tex_cudaResult, unsigned int size_x,
                      unsigned int size_y);
void createTextureSrc(GLuint *tex_screen, unsigned int size_x,
                      unsigned int size_y);
void deleteTexture(GLuint *tex);
void createDepthBuffer(GLuint *depth, unsigned int size_x, unsigned int size_y);
void deleteDepthBuffer(GLuint *depth);
void createFramebuffer(GLuint *fbo, GLuint color, GLuint depth);
void deleteFramebuffer(GLuint *fbo);

// rendering callbacks
void display();
void idle();
void keyboard(unsigned char key, int x, int y);
void reshape(int w, int h);
void mainMenu(int i);

////////////////////////////////////////////////////////////////////////////////
//! Run the Cuda part of the computation
////////////////////////////////////////////////////////////////////////////////
void process(int width, int height, int radius) {
  cudaArray *in_array;
  unsigned int *out_data;

#ifdef USE_TEXSUBIMAGE2D
  checkCudaErrors(cudaGraphicsMapResources(1, &cuda_pbo_dest_resource, 0));
  size_t num_bytes;
  checkCudaErrors(cudaGraphicsResourceGetMappedPointer(
      (void **)&out_data, &num_bytes, cuda_pbo_dest_resource));
// printf("CUDA mapped pointer of pbo_out: May access %ld bytes, expected %d\n",
// num_bytes, size_tex_data);
#else
  out_data = cuda_dest_resource;
#endif

  // map buffer objects to get CUDA device pointers
  checkCudaErrors(cudaGraphicsMapResources(1, &cuda_tex_screen_resource, 0));
  // printf("Mapping tex_in\n");
  checkCudaErrors(cudaGraphicsSubResourceGetMappedArray(
      &in_array, cuda_tex_screen_resource, 0, 0));

  // calculate grid size
  dim3 block(16, 16, 1);
  // dim3 block(16, 16, 1);
  dim3 grid(width / block.x, height / block.y, 1);
  int sbytes = (block.x + (2 * radius)) * (block.y + (2 * radius)) *
               sizeof(unsigned int);

  // execute CUDA kernel
  launch_cudaProcess(grid, block, sbytes, in_array, out_data, width, height,
                     block.x + (2 * radius), radius, 0.8f, 4.0f);

  checkCudaErrors(cudaGraphicsUnmapResources(1, &cuda_tex_screen_resource, 0));
#ifdef USE_TEXSUBIMAGE2D
  checkCudaErrors(cudaGraphicsUnmapResources(1, &cuda_pbo_dest_resource, 0));
#endif
  checkCudaErrors(cudaDestroyTextureObject(inTexObject));
}

#ifdef USE_TEXSUBIMAGE2D
////////////////////////////////////////////////////////////////////////////////
//! Create PBO
////////////////////////////////////////////////////////////////////////////////
void createPBO(GLuint *pbo, struct cudaGraphicsResource **pbo_resource) {
  // set up vertex data parameter
  num_texels = image_width * image_height;
  num_values = num_texels * 4;
  size_tex_data = sizeof(GLubyte) * num_values;
  void *data = malloc(size_tex_data);

  // create buffer object
  glGenBuffers(1, pbo);
  glBindBuffer(GL_ARRAY_BUFFER, *pbo);
  glBufferData(GL_ARRAY_BUFFER, size_tex_data, data, GL_DYNAMIC_DRAW);
  free(data);

  glBindBuffer(GL_ARRAY_BUFFER, 0);

  // register this buffer object with CUDA
  checkCudaErrors(cudaGraphicsGLRegisterBuffer(pbo_resource, *pbo,
                                               cudaGraphicsMapFlagsNone));

  SDK_CHECK_ERROR_GL();
}

void deletePBO(GLuint *pbo) {
  glDeleteBuffers(1, pbo);
  SDK_CHECK_ERROR_GL();
  *pbo = 0;
}
#endif

const GLenum fbo_targets[] = {
    GL_COLOR_ATTACHMENT0_EXT, GL_COLOR_ATTACHMENT1_EXT,
    GL_COLOR_ATTACHMENT2_EXT, GL_COLOR_ATTACHMENT3_EXT};

#ifndef USE_TEXSUBIMAGE2D
static const char *glsl_drawtex_vertshader_src =
    "void main(void)\n"
    "{\n"
    "	gl_Position = gl_Vertex;\n"
    "	gl_TexCoord[0].xy = gl_MultiTexCoord0.xy;\n"
    "}\n";

static const char *glsl_drawtex_fragshader_src =
    "#version 130\n"
    "uniform usampler2D texImage;\n"
    "void main()\n"
    "{\n"
    "   vec4 c = texture(texImage, gl_TexCoord[0].xy);\n"
    "	gl_FragColor = c / 255.0;\n"
    "}\n";
#endif

static const char *glsl_drawpot_fragshader_src =
// WARNING: seems like the gl_FragColor doesn't want to output >1 colors...
// you need version 1.3 so you can define a uvec4 output...
// but MacOSX complains about not supporting 1.3 !!
// for now, the mode where we use RGBA8UI may not work properly for Apple : only
// RGBA16F works (default)
#if defined(__APPLE__) || defined(MACOSX)
    "void main()\n"
    "{"
    "  gl_FragColor = vec4(gl_Color * 255.0);\n"
    "}\n";
#else
    "#version 130\n"
    "in vec4 inColor;\n"
    "out uvec4 FragColor;\n"
    "void main()\n"
    "{"
    "  FragColor = uvec4(inColor.xyz * 255.0, 255.0);\n"
    "}\n";
#endif

////////////////////////////////////////////////////////////////////////////////
//! render a simple 3D scene
////////////////////////////////////////////////////////////////////////////////
void renderScene(bool colorScale) {
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  if (colorScale) {
    glUseProgram(shDrawPot);
    glBindFragDataLocationEXT(shDrawPot, 0, "FragColor");
    SDK_CHECK_ERROR_GL();
  }

  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
  glTranslatef(0.0, 0.0, -3.0);
  glRotatef(rotate[0], 1.0, 0.0, 0.0);
  glRotatef(rotate[1], 0.0, 1.0, 0.0);
  glRotatef(rotate[2], 0.0, 0.0, 1.0);

  glViewport(0, 0, 512, 512);

  glEnable(GL_LIGHTING);
  glEnable(GL_DEPTH_TEST);

  glutSolidTeapot(1.0);

  if (colorScale) {
    glUseProgram(0);
  }

  SDK_CHECK_ERROR_GL();
}

// copy image and process using CUDA
void processImage() {
  // run the Cuda kernel
  process(image_width, image_height, blur_radius);

// CUDA generated data in cuda memory or in a mapped PBO made of BGRA 8 bits
// 2 solutions, here :
// - use glTexSubImage2D(), there is the potential to loose performance in
// possible hidden conversion
// - map the texture and blit the result thanks to CUDA API
#ifdef USE_TEXSUBIMAGE2D
  glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo_dest);

  glBindTexture(GL_TEXTURE_2D, tex_cudaResult);
  glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, image_width, image_height, GL_RGBA,
                  GL_UNSIGNED_BYTE, NULL);
  SDK_CHECK_ERROR_GL();
  glBindBuffer(GL_PIXEL_PACK_BUFFER_ARB, 0);
  glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
#else
  // We want to copy cuda_dest_resource data to the texture
  // map buffer objects to get CUDA device pointers
  cudaArray *texture_ptr;
  checkCudaErrors(cudaGraphicsMapResources(1, &cuda_tex_result_resource, 0));
  checkCudaErrors(cudaGraphicsSubResourceGetMappedArray(
      &texture_ptr, cuda_tex_result_resource, 0, 0));

  int num_texels = image_width * image_height;
  int num_values = num_texels * 4;
  int size_tex_data = sizeof(GLubyte) * num_values;
  checkCudaErrors(cudaMemcpyToArray(texture_ptr, 0, 0, cuda_dest_resource,
                                    size_tex_data, cudaMemcpyDeviceToDevice));

  checkCudaErrors(cudaGraphicsUnmapResources(1, &cuda_tex_result_resource, 0));
#endif
}

// display image to the screen as textured quad
void displayImage(GLuint texture) {
  glBindTexture(GL_TEXTURE_2D, texture);
  glEnable(GL_TEXTURE_2D);
  glDisable(GL_DEPTH_TEST);
  glDisable(GL_LIGHTING);
  glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);

  glMatrixMode(GL_PROJECTION);
  glPushMatrix();
  glLoadIdentity();
  glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);

  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();

  glViewport(0, 0, window_width, window_height);

// if the texture is a 8 bits UI, scale the fetch with a GLSL shader
#ifndef USE_TEXSUBIMAGE2D
  glUseProgram(shDrawTex);
  GLint id = glGetUniformLocation(shDrawTex, "texImage");
  glUniform1i(id, 0);  // texture unit 0 to "texImage"
  SDK_CHECK_ERROR_GL();
#endif

  glBegin(GL_QUADS);
  glTexCoord2f(0.0, 0.0);
  glVertex3f(-1.0, -1.0, 0.5);
  glTexCoord2f(1.0, 0.0);
  glVertex3f(1.0, -1.0, 0.5);
  glTexCoord2f(1.0, 1.0);
  glVertex3f(1.0, 1.0, 0.5);
  glTexCoord2f(0.0, 1.0);
  glVertex3f(-1.0, 1.0, 0.5);
  glEnd();

  glMatrixMode(GL_PROJECTION);
  glPopMatrix();

  glDisable(GL_TEXTURE_2D);

#ifndef USE_TEXSUBIMAGE2D
  glUseProgram(0);
#endif
  SDK_CHECK_ERROR_GL();
}

////////////////////////////////////////////////////////////////////////////////
//! Display callback
////////////////////////////////////////////////////////////////////////////////
void display() {
  sdkStartTimer(&timer);

  if (enable_cuda) {
    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, framebuffer);
#ifndef USE_TEXTURE_RGBA8UI
    renderScene(false);
#else
    renderScene(true);  // output of fragment * by 255 (for RGBA8UI texture)
#endif
    processImage();
    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
    displayImage(tex_cudaResult);
  } else {
    renderScene(false);
  }

  // NOTE: I needed to add this call so the timing is consistent.
  // Need to investigate why
  cudaDeviceSynchronize();
  sdkStopTimer(&timer);

  // flip backbuffer
  glutSwapBuffers();

  // If specified, Check rendering against reference,
  if (ref_file && g_CheckRender && g_CheckRender->IsQAReadback()) {
    static int pass = 0;

    if (pass > 0) {
      g_CheckRender->readback(window_width, window_height);
      char currentOutputPPM[256];
      sprintf(currentOutputPPM, "teapot_%d.ppm", blur_radius);
      g_CheckRender->savePPM(currentOutputPPM, true, NULL);

      if (!g_CheckRender->PPMvsPPM(currentOutputPPM,
                                   sdkFindFilePath(ref_file, pArgv[0]),
                                   MAX_EPSILON, 0.30f)) {
        g_TotalErrors++;
      }

      Cleanup((g_TotalErrors == 0) ? EXIT_SUCCESS : EXIT_FAILURE);
    }

    pass++;
  }

  // Update fps counter, fps/title display and log
  if (++fpsCount == fpsLimit) {
    char cTitle[256];
    float fps = 1000.0f / sdkGetAverageTimerValue(&timer);
    sprintf(cTitle, "CUDA GL Post Processing (%d x %d): %.1f fps", window_width,
            window_height, fps);
    glutSetWindowTitle(cTitle);
    // printf("%s\n", cTitle);
    fpsCount = 0;
    fpsLimit = (int)((fps > 1.0f) ? fps : 1.0f);
    sdkResetTimer(&timer);
  }
}

void timerEvent(int value) {
  if (animate) {
    rotate[0] += 0.2f;

    if (rotate[0] > 360.0f) {
      rotate[0] -= 360.0f;
    }

    rotate[1] += 0.6f;

    if (rotate[1] > 360.0f) {
      rotate[1] -= 360.0f;
    }

    rotate[2] += 1.0f;

    if (rotate[2] > 360.0f) {
      rotate[2] -= 360.0f;
    }
  }

  glutPostRedisplay();
  glutTimerFunc(REFRESH_DELAY, timerEvent, 0);
}

////////////////////////////////////////////////////////////////////////////////
//! Keyboard events handler
////////////////////////////////////////////////////////////////////////////////
void keyboard(unsigned char key, int /*x*/, int /*y*/) {
  switch (key) {
    case (27):
      Cleanup(EXIT_SUCCESS);
      break;

    case ' ':
      enable_cuda ^= 1;
#ifdef USE_TEXTURE_RGBA8UI

      if (enable_cuda) {
        glClearColorIuiEXT(128, 128, 128, 255);
      } else {
        glClearColor(0.5, 0.5, 0.5, 1.0);
      }

#endif
      break;

    case 'a':
      animate ^= 1;
      break;

    case '=':
    case '+':
      if (blur_radius < 16) {
        blur_radius++;
      }

      printf("radius = %d\n", blur_radius);
      break;

    case '-':
      if (blur_radius > 1) {
        blur_radius--;
      }

      printf("radius = %d\n", blur_radius);
      break;
  }
}

void reshape(int w, int h) {
  window_width = w;
  window_height = h;
}

void mainMenu(int i) { keyboard((unsigned char)i, 0, 0); }

////////////////////////////////////////////////////////////////////////////////
//!
////////////////////////////////////////////////////////////////////////////////
void createTextureSrc(GLuint *tex_screen, unsigned int size_x,
                      unsigned int size_y) {
  // create a texture
  glGenTextures(1, tex_screen);
  glBindTexture(GL_TEXTURE_2D, *tex_screen);

  // set basic parameters
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

// buffer data
#ifndef USE_TEXTURE_RGBA8UI
  printf("Creating a Texture render target GL_RGBA16F_ARB\n");
  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, size_x, size_y, 0, GL_RGBA,
               GL_UNSIGNED_BYTE, NULL);
#else
  printf("Creating a Texture render target GL_RGBA8UI_EXT\n");
  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8UI_EXT, size_x, size_y, 0,
               GL_RGBA_INTEGER_EXT, GL_UNSIGNED_BYTE, NULL);
#endif
  SDK_CHECK_ERROR_GL();
  // register this texture with CUDA
  checkCudaErrors(cudaGraphicsGLRegisterImage(&cuda_tex_screen_resource,
                                              *tex_screen, GL_TEXTURE_2D,
                                              cudaGraphicsMapFlagsReadOnly));
}

////////////////////////////////////////////////////////////////////////////////
//!
////////////////////////////////////////////////////////////////////////////////
void createTextureDst(GLuint *tex_cudaResult, unsigned int size_x,
                      unsigned int size_y) {
  // create a texture
  glGenTextures(1, tex_cudaResult);
  glBindTexture(GL_TEXTURE_2D, *tex_cudaResult);

  // set basic parameters
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

#ifdef USE_TEXSUBIMAGE2D
  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, size_x, size_y, 0, GL_RGBA,
               GL_UNSIGNED_BYTE, NULL);
  SDK_CHECK_ERROR_GL();
#else
  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8UI_EXT, size_x, size_y, 0,
               GL_RGBA_INTEGER_EXT, GL_UNSIGNED_BYTE, NULL);
  SDK_CHECK_ERROR_GL();
  // register this texture with CUDA
  checkCudaErrors(cudaGraphicsGLRegisterImage(
      &cuda_tex_result_resource, *tex_cudaResult, GL_TEXTURE_2D,
      cudaGraphicsMapFlagsWriteDiscard));
#endif
}

////////////////////////////////////////////////////////////////////////////////
//!
////////////////////////////////////////////////////////////////////////////////
void deleteTexture(GLuint *tex) {
  glDeleteTextures(1, tex);
  SDK_CHECK_ERROR_GL();

  *tex = 0;
}

////////////////////////////////////////////////////////////////////////////////
//!
////////////////////////////////////////////////////////////////////////////////
void createDepthBuffer(GLuint *depth, unsigned int size_x,
                       unsigned int size_y) {
  // create a renderbuffer
  glGenRenderbuffersEXT(1, depth);
  glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, *depth);

  // allocate storage
  glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT24, size_x,
                           size_y);

  // clean up
  glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, 0);

  SDK_CHECK_ERROR_GL();
}

////////////////////////////////////////////////////////////////////////////////
//!
////////////////////////////////////////////////////////////////////////////////
// void
// createRenderBuffer(GLuint* render, unsigned int size_x, unsigned int size_y)
//{
//    // create a renderbuffer
//    glGenRenderbuffersEXT(1, render);
//    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, *render);
//
//    // allocate storage
//    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGBA8, size_x, size_y);
//
//    // clean up
//    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, 0);
//
//    SDK_CHECK_ERROR_GL();
//
//  checkCudaErrors(cudaGraphicsGLRegisterImage(&cuda_tex_screen_resource,
//  *render,
//                        GL_RENDERBUFFER_EXT, cudaGraphicsMapFlagsReadOnly));
//}

////////////////////////////////////////////////////////////////////////////////
//!
////////////////////////////////////////////////////////////////////////////////
void deleteDepthBuffer(GLuint *depth) {
  glDeleteRenderbuffersEXT(1, depth);
  SDK_CHECK_ERROR_GL();

  *depth = 0;
}

////////////////////////////////////////////////////////////////////////////////
//!
////////////////////////////////////////////////////////////////////////////////
void createFramebuffer(GLuint *fbo, GLuint color, GLuint depth) {
  // create and bind a framebuffer
  glGenFramebuffersEXT(1, fbo);
  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, *fbo);

  // attach images
  glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
                            GL_TEXTURE_2D, color, 0);
  // glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
  // GL_RENDERBUFFER_EXT, color);
  glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
                               GL_RENDERBUFFER_EXT, depth);

  // clean up
  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);

  SDK_CHECK_ERROR_GL();
}

////////////////////////////////////////////////////////////////////////////////
//!
////////////////////////////////////////////////////////////////////////////////
void deleteFramebuffer(GLuint *fbo) {
  glDeleteFramebuffersEXT(1, fbo);
  SDK_CHECK_ERROR_GL();

  *fbo = 0;
}

////////////////////////////////////////////////////////////////////////////////
// Program main
////////////////////////////////////////////////////////////////////////////////
int main(int argc, char **argv) {
#if defined(__linux__)
  char *Xstatus = getenv("DISPLAY");
  if (Xstatus == NULL) {
    printf("Waiving execution as X server is not running\n");
    exit(EXIT_WAIVED);
  }
  setenv("DISPLAY", ":0", 0);
#endif

  printf("%s Starting...\n\n", argv[0]);

  if (checkCmdLineFlag(argc, (const char **)argv, "radius") &&
      checkCmdLineFlag(argc, (const char **)argv, "file")) {
    getCmdLineArgumentString(argc, (const char **)argv, "file", &ref_file);
    blur_radius = getCmdLineArgumentInt(argc, (const char **)argv, "radius");
  }

  pArgc = &argc;
  pArgv = argv;

  // use command-line specified CUDA device, otherwise use device with highest
  // Gflops/s
  if (checkCmdLineFlag(argc, (const char **)argv, "device")) {
    printf("[%s]\n", argv[0]);
    printf("   Does not explicitly support -device=n\n");
    printf(
        "   This sample requires OpenGL.  Only -file=<reference> -radius=<n> "
        "are supported\n");
    printf("exiting...\n");
    exit(EXIT_WAIVED);
  }

  if (ref_file) {
    printf("(Test with OpenGL verification)\n");
    animate = false;

    runStdProgram(argc, argv);
  } else {
    printf("(Interactive OpenGL Demo)\n");
    animate = true;

    runStdProgram(argc, argv);
  }

  exit(EXIT_SUCCESS);
}

////////////////////////////////////////////////////////////////////////////////
//!
////////////////////////////////////////////////////////////////////////////////
void FreeResource() {
  sdkDeleteTimer(&timer);

  // unregister this buffer object with CUDA
  checkCudaErrors(cudaGraphicsUnregisterResource(cuda_tex_screen_resource));
#ifdef USE_TEXSUBIMAGE2D
  checkCudaErrors(cudaGraphicsUnregisterResource(cuda_pbo_dest_resource));
  deletePBO(&pbo_dest);
#else
  cudaFree(cuda_dest_resource);
#endif
  deleteTexture(&tex_screen);
  deleteTexture(&tex_cudaResult);
  deleteDepthBuffer(&depth_buffer);
  deleteFramebuffer(&framebuffer);

  if (iGLUTWindowHandle) {
    glutDestroyWindow(iGLUTWindowHandle);
  }

  // finalize logs and leave
  printf("postProcessGL.exe Exiting...\n");
}

void Cleanup(int iExitCode) {
  FreeResource();
  printf("Images are %s\n",
         (iExitCode == EXIT_SUCCESS) ? "Matching" : "Not Matching");
  exit(EXIT_SUCCESS);
}

////////////////////////////////////////////////////////////////////////////////
//!
////////////////////////////////////////////////////////////////////////////////
GLuint compileGLSLprogram(const char *vertex_shader_src,
                          const char *fragment_shader_src) {
  GLuint v, f, p = 0;

  p = glCreateProgram();

  if (vertex_shader_src) {
    v = glCreateShader(GL_VERTEX_SHADER);
    glShaderSource(v, 1, &vertex_shader_src, NULL);
    glCompileShader(v);

    // check if shader compiled
    GLint compiled = 0;
    glGetShaderiv(v, GL_COMPILE_STATUS, &compiled);

    if (!compiled) {
      //#ifdef NV_REPORT_COMPILE_ERRORS
      char temp[256] = "";
      glGetShaderInfoLog(v, 256, NULL, temp);
      printf("Vtx Compile failed:\n%s\n", temp);
      //#endif
      glDeleteShader(v);
      return 0;
    } else {
      glAttachShader(p, v);
    }
  }

  if (fragment_shader_src) {
    f = glCreateShader(GL_FRAGMENT_SHADER);
    glShaderSource(f, 1, &fragment_shader_src, NULL);
    glCompileShader(f);

    // check if shader compiled
    GLint compiled = 0;
    glGetShaderiv(f, GL_COMPILE_STATUS, &compiled);

    if (!compiled) {
      //#ifdef NV_REPORT_COMPILE_ERRORS
      char temp[256] = "";
      glGetShaderInfoLog(f, 256, NULL, temp);
      printf("frag Compile failed:\n%s\n", temp);
      //#endif
      glDeleteShader(f);
      return 0;
    } else {
      glAttachShader(p, f);
    }
  }

  glLinkProgram(p);

  int infologLength = 0;
  int charsWritten = 0;

  GLint linked = 0;
  glGetProgramiv(p, GL_LINK_STATUS, &linked);

  if (linked == 0) {
    glGetProgramiv(p, GL_INFO_LOG_LENGTH, (GLint *)&infologLength);

    if (infologLength > 0) {
      char *infoLog = (char *)malloc(infologLength);
      glGetProgramInfoLog(p, infologLength, (GLsizei *)&charsWritten, infoLog);
      printf("Shader compilation error: %s\n", infoLog);
      free(infoLog);
    }
  }

  return p;
}

////////////////////////////////////////////////////////////////////////////////
//! Allocate the "render target" of CUDA
////////////////////////////////////////////////////////////////////////////////
#ifndef USE_TEXSUBIMAGE2D
void initCUDABuffers() {
  // set up vertex data parameter
  num_texels = image_width * image_height;
  num_values = num_texels * 4;
  size_tex_data = sizeof(GLubyte) * num_values;
  checkCudaErrors(cudaMalloc((void **)&cuda_dest_resource, size_tex_data));
  // checkCudaErrors(cudaHostAlloc((void**)&cuda_dest_resource, size_tex_data,
  // ));
}
#endif

////////////////////////////////////////////////////////////////////////////////
//!
////////////////////////////////////////////////////////////////////////////////
void initGLBuffers() {
// create pbo
#ifdef USE_TEXSUBIMAGE2D
  createPBO(&pbo_dest, &cuda_pbo_dest_resource);
#endif
  // create texture that will receive the result of CUDA
  createTextureDst(&tex_cudaResult, image_width, image_height);

  // create texture for blitting onto the screen
  createTextureSrc(&tex_screen, image_width, image_height);
  // createRenderBuffer(&tex_screen, image_width, image_height); // Doesn't work

  // create a depth buffer for offscreen rendering
  createDepthBuffer(&depth_buffer, image_width, image_height);

  // create a framebuffer for offscreen rendering
  createFramebuffer(&framebuffer, tex_screen, depth_buffer);

  // load shader programs
  shDrawPot = compileGLSLprogram(NULL, glsl_drawpot_fragshader_src);

#ifndef USE_TEXSUBIMAGE2D
  shDrawTex = compileGLSLprogram(glsl_drawtex_vertshader_src,
                                 glsl_drawtex_fragshader_src);
#endif
  SDK_CHECK_ERROR_GL();
}

////////////////////////////////////////////////////////////////////////////////
//! Run standard demo loop with or without GL verification
////////////////////////////////////////////////////////////////////////////////
void runStdProgram(int argc, char **argv) {
  // First initialize OpenGL context, so we can properly set the GL for CUDA.
  // This is necessary in order to achieve optimal performance with OpenGL/CUDA
  // interop.
  if (false == initGL(&argc, argv)) {
    return;
  }

  // Now initialize CUDA context
  findCudaDevice(argc, (const char **)argv);

  sdkCreateTimer(&timer);
  sdkResetTimer(&timer);

  // register callbacks
  glutDisplayFunc(display);
  glutKeyboardFunc(keyboard);
  glutReshapeFunc(reshape);
  glutTimerFunc(REFRESH_DELAY, timerEvent, 0);

  // create menu
  glutCreateMenu(mainMenu);
  glutAddMenuEntry("Toggle CUDA Post Processing (on/off) [ ]", ' ');
  glutAddMenuEntry("Toggle Animation (on/off) [a]", 'a');
  glutAddMenuEntry("Increase Blur Radius [=]", '=');
  glutAddMenuEntry("Decrease Blur Radius [-]", '-');
  glutAddMenuEntry("Quit (esc)", '\033');
  glutAttachMenu(GLUT_RIGHT_BUTTON);

  initGLBuffers();
#ifndef USE_TEXSUBIMAGE2D
  initCUDABuffers();
#endif

  // Creating the Auto-Validation Code
  if (ref_file) {
    g_CheckRender = new CheckBackBuffer(window_width, window_height, 4);
    g_CheckRender->setPixelFormat(GL_RGBA);
    g_CheckRender->setExecPath(argv[0]);
    g_CheckRender->EnableQAReadback(true);
  }

  printf(
      "\n"
      "\tControls\n"
      "\t(right click mouse button for Menu)\n"
      "\t[ ] : Toggle CUDA Post Processing (on/off)\n"
      "\t[a] : Toggle Animation (on/off)\n"
      "\t[=] : Increase Blur Radius\n"
      "\t[-] : Decrease Blur Radius\n"
      "\t[esc] - Quit\n\n");

  // start rendering mainloop
  glutMainLoop();

  // Normally unused return path
  Cleanup(EXIT_SUCCESS);
}

////////////////////////////////////////////////////////////////////////////////
//! Initialize GL
////////////////////////////////////////////////////////////////////////////////
bool initGL(int *argc, char **argv) {
  // Create GL context
  glutInit(argc, argv);
  glutInitDisplayMode(GLUT_RGBA | GLUT_ALPHA | GLUT_DOUBLE | GLUT_DEPTH);
  glutInitWindowSize(window_width, window_height);
  iGLUTWindowHandle = glutCreateWindow("CUDA OpenGL post-processing");

  // initialize necessary OpenGL extensions
  if (!isGLVersionSupported(2, 0) ||
      !areGLExtensionsSupported("GL_ARB_pixel_buffer_object "
                                "GL_EXT_framebuffer_object")) {
    printf("ERROR: Support for necessary OpenGL extensions missing.");
    fflush(stderr);
    return false;
  }

// default initialization
#ifndef USE_TEXTURE_RGBA8UI
  glClearColor(0.5, 0.5, 0.5, 1.0);
#else
  glClearColorIuiEXT(128, 128, 128, 255);
#endif
  glDisable(GL_DEPTH_TEST);

  // viewport
  glViewport(0, 0, window_width, window_height);

  // projection
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluPerspective(60.0, (GLfloat)window_width / (GLfloat)window_height, 0.1f,
                 10.0f);

  glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);

  glEnable(GL_LIGHT0);
  float red[] = {1.0f, 0.1f, 0.1f, 1.0f};
  float white[] = {1.0f, 1.0f, 1.0f, 1.0f};
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, red);
  glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, white);
  glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 60.0f);

  SDK_CHECK_ERROR_GL();

  return true;
}