cuda-samples/Samples/oceanFFT/oceanFFT.cpp
2021-10-21 16:34:49 +05:30

896 lines
26 KiB
C++

/* 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
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
FFT-based Ocean simulation
based on original code by Yury Uralsky and Calvin Lin
This sample demonstrates how to use CUFFT to synthesize and
render an ocean surface in real-time.
See Jerry Tessendorf's Siggraph course notes for more details:
http://tessendorf.org/reports.html
It also serves as an example of how to generate multiple vertex
buffer streams from CUDA and render them using GLSL shaders.
*/
#if defined(WIN32) || defined(_WIN32) || defined(WIN64) || defined(_WIN64)
#define WINDOWS_LEAN_AND_MEAN
#define NOMINMAX
#include <windows.h>
#endif
// includes
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <helper_gl.h>
#include <cuda_runtime.h>
#include <cuda_gl_interop.h>
#include <cufft.h>
#include <helper_cuda.h>
#include <helper_functions.h>
#include <math_constants.h>
#if defined(__APPLE__) || defined(MACOSX)
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
#include <GLUT/glut.h>
#else
#include <GL/freeglut.h>
#endif
#include <rendercheck_gl.h>
const char *sSDKsample = "CUDA FFT Ocean Simulation";
#define MAX_EPSILON 0.10f
#define THRESHOLD 0.15f
#define REFRESH_DELAY 10 // ms
////////////////////////////////////////////////////////////////////////////////
// constants
unsigned int windowW = 512, windowH = 512;
const unsigned int meshSize = 256;
const unsigned int spectrumW = meshSize + 4;
const unsigned int spectrumH = meshSize + 1;
const int frameCompare = 4;
// OpenGL vertex buffers
GLuint posVertexBuffer;
GLuint heightVertexBuffer, slopeVertexBuffer;
struct cudaGraphicsResource *cuda_posVB_resource, *cuda_heightVB_resource,
*cuda_slopeVB_resource; // handles OpenGL-CUDA exchange
GLuint indexBuffer;
GLuint shaderProg;
char *vertShaderPath = 0, *fragShaderPath = 0;
// mouse controls
int mouseOldX, mouseOldY;
int mouseButtons = 0;
float rotateX = 20.0f, rotateY = 0.0f;
float translateX = 0.0f, translateY = 0.0f, translateZ = -2.0f;
bool animate = true;
bool drawPoints = false;
bool wireFrame = false;
bool g_hasDouble = false;
// FFT data
cufftHandle fftPlan;
float2 *d_h0 = 0; // heightfield at time 0
float2 *h_h0 = 0;
float2 *d_ht = 0; // heightfield at time t
float2 *d_slope = 0;
// pointers to device object
float *g_hptr = NULL;
float2 *g_sptr = NULL;
// simulation parameters
const float g = 9.81f; // gravitational constant
const float A = 1e-7f; // wave scale factor
const float patchSize = 100; // patch size
float windSpeed = 100.0f;
float windDir = CUDART_PI_F / 3.0f;
float dirDepend = 0.07f;
StopWatchInterface *timer = NULL;
float animTime = 0.0f;
float prevTime = 0.0f;
float animationRate = -0.001f;
// Auto-Verification Code
const int frameCheckNumber = 4;
int fpsCount = 0; // FPS count for averaging
int fpsLimit = 1; // FPS limit for sampling
unsigned int frameCount = 0;
unsigned int g_TotalErrors = 0;
////////////////////////////////////////////////////////////////////////////////
// kernels
//#include <oceanFFT_kernel.cu>
extern "C" void cudaGenerateSpectrumKernel(float2 *d_h0, float2 *d_ht,
unsigned int in_width,
unsigned int out_width,
unsigned int out_height,
float animTime, float patchSize);
extern "C" void cudaUpdateHeightmapKernel(float *d_heightMap, float2 *d_ht,
unsigned int width,
unsigned int height, bool autoTest);
extern "C" void cudaCalculateSlopeKernel(float *h, float2 *slopeOut,
unsigned int width,
unsigned int height);
////////////////////////////////////////////////////////////////////////////////
// forward declarations
void runAutoTest(int argc, char **argv);
void runGraphicsTest(int argc, char **argv);
// GL functionality
bool initGL(int *argc, char **argv);
void createVBO(GLuint *vbo, int size);
void deleteVBO(GLuint *vbo);
void createMeshIndexBuffer(GLuint *id, int w, int h);
void createMeshPositionVBO(GLuint *id, int w, int h);
GLuint loadGLSLProgram(const char *vertFileName, const char *fragFileName);
// rendering callbacks
void display();
void keyboard(unsigned char key, int x, int y);
void mouse(int button, int state, int x, int y);
void motion(int x, int y);
void reshape(int w, int h);
void timerEvent(int value);
// Cuda functionality
void runCuda();
void runCudaTest(char *exec_path);
void generate_h0(float2 *h0);
////////////////////////////////////////////////////////////////////////////////
// Program main
////////////////////////////////////////////////////////////////////////////////
int main(int argc, char **argv) {
printf(
"NOTE: The CUDA Samples are not meant for performance measurements. "
"Results may vary when GPU Boost is enabled.\n\n");
// check for command line arguments
if (checkCmdLineFlag(argc, (const char **)argv, "qatest")) {
animate = false;
fpsLimit = frameCheckNumber;
runAutoTest(argc, argv);
} else {
printf(
"[%s]\n\n"
"Left mouse button - rotate\n"
"Middle mouse button - pan\n"
"Right mouse button - zoom\n"
"'w' key - toggle wireframe\n",
sSDKsample);
runGraphicsTest(argc, argv);
}
exit(EXIT_SUCCESS);
}
////////////////////////////////////////////////////////////////////////////////
//! Run test
////////////////////////////////////////////////////////////////////////////////
void runAutoTest(int argc, char **argv) {
printf("%s Starting...\n\n", argv[0]);
// Cuda init
int dev = findCudaDevice(argc, (const char **)argv);
cudaDeviceProp deviceProp;
checkCudaErrors(cudaGetDeviceProperties(&deviceProp, dev));
printf("Compute capability %d.%d\n", deviceProp.major, deviceProp.minor);
// create FFT plan
checkCudaErrors(cufftPlan2d(&fftPlan, meshSize, meshSize, CUFFT_C2C));
// allocate memory
int spectrumSize = spectrumW * spectrumH * sizeof(float2);
checkCudaErrors(cudaMalloc((void **)&d_h0, spectrumSize));
h_h0 = (float2 *)malloc(spectrumSize);
generate_h0(h_h0);
checkCudaErrors(cudaMemcpy(d_h0, h_h0, spectrumSize, cudaMemcpyHostToDevice));
int outputSize = meshSize * meshSize * sizeof(float2);
checkCudaErrors(cudaMalloc((void **)&d_ht, outputSize));
checkCudaErrors(cudaMalloc((void **)&d_slope, outputSize));
sdkCreateTimer(&timer);
sdkStartTimer(&timer);
prevTime = sdkGetTimerValue(&timer);
runCudaTest(argv[0]);
checkCudaErrors(cudaFree(d_ht));
checkCudaErrors(cudaFree(d_slope));
checkCudaErrors(cudaFree(d_h0));
checkCudaErrors(cufftDestroy(fftPlan));
free(h_h0);
exit(g_TotalErrors == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
}
////////////////////////////////////////////////////////////////////////////////
//! Run test
////////////////////////////////////////////////////////////////////////////////
void runGraphicsTest(int argc, char **argv) {
#if defined(__linux__)
setenv("DISPLAY", ":0", 0);
#endif
printf("[%s] ", sSDKsample);
printf("\n");
if (checkCmdLineFlag(argc, (const char **)argv, "device")) {
printf("[%s]\n", argv[0]);
printf(" Does not explicitly support -device=n in OpenGL mode\n");
printf(" To use -device=n, the sample must be running w/o OpenGL\n\n");
printf(" > %s -device=n -qatest\n", argv[0]);
printf("exiting...\n");
exit(EXIT_SUCCESS);
}
// 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;
}
findCudaDevice(argc, (const char **)argv);
// create FFT plan
checkCudaErrors(cufftPlan2d(&fftPlan, meshSize, meshSize, CUFFT_C2C));
// allocate memory
int spectrumSize = spectrumW * spectrumH * sizeof(float2);
checkCudaErrors(cudaMalloc((void **)&d_h0, spectrumSize));
h_h0 = (float2 *)malloc(spectrumSize);
generate_h0(h_h0);
checkCudaErrors(cudaMemcpy(d_h0, h_h0, spectrumSize, cudaMemcpyHostToDevice));
int outputSize = meshSize * meshSize * sizeof(float2);
checkCudaErrors(cudaMalloc((void **)&d_ht, outputSize));
checkCudaErrors(cudaMalloc((void **)&d_slope, outputSize));
sdkCreateTimer(&timer);
sdkStartTimer(&timer);
prevTime = sdkGetTimerValue(&timer);
// create vertex buffers and register with CUDA
createVBO(&heightVertexBuffer, meshSize * meshSize * sizeof(float));
checkCudaErrors(
cudaGraphicsGLRegisterBuffer(&cuda_heightVB_resource, heightVertexBuffer,
cudaGraphicsMapFlagsWriteDiscard));
createVBO(&slopeVertexBuffer, outputSize);
checkCudaErrors(
cudaGraphicsGLRegisterBuffer(&cuda_slopeVB_resource, slopeVertexBuffer,
cudaGraphicsMapFlagsWriteDiscard));
// create vertex and index buffer for mesh
createMeshPositionVBO(&posVertexBuffer, meshSize, meshSize);
createMeshIndexBuffer(&indexBuffer, meshSize, meshSize);
runCuda();
// register callbacks
glutDisplayFunc(display);
glutKeyboardFunc(keyboard);
glutMouseFunc(mouse);
glutMotionFunc(motion);
glutReshapeFunc(reshape);
glutTimerFunc(REFRESH_DELAY, timerEvent, 0);
// start rendering mainloop
glutMainLoop();
}
float urand() { return rand() / (float)RAND_MAX; }
// Generates Gaussian random number with mean 0 and standard deviation 1.
float gauss() {
float u1 = urand();
float u2 = urand();
if (u1 < 1e-6f) {
u1 = 1e-6f;
}
return sqrtf(-2 * logf(u1)) * cosf(2 * CUDART_PI_F * u2);
}
// Phillips spectrum
// (Kx, Ky) - normalized wave vector
// Vdir - wind angle in radians
// V - wind speed
// A - constant
float phillips(float Kx, float Ky, float Vdir, float V, float A,
float dir_depend) {
float k_squared = Kx * Kx + Ky * Ky;
if (k_squared == 0.0f) {
return 0.0f;
}
// largest possible wave from constant wind of velocity v
float L = V * V / g;
float k_x = Kx / sqrtf(k_squared);
float k_y = Ky / sqrtf(k_squared);
float w_dot_k = k_x * cosf(Vdir) + k_y * sinf(Vdir);
float phillips = A * expf(-1.0f / (k_squared * L * L)) /
(k_squared * k_squared) * w_dot_k * w_dot_k;
// filter out waves moving opposite to wind
if (w_dot_k < 0.0f) {
phillips *= dir_depend;
}
// damp out waves with very small length w << l
// float w = L / 10000;
// phillips *= expf(-k_squared * w * w);
return phillips;
}
// Generate base heightfield in frequency space
void generate_h0(float2 *h0) {
for (unsigned int y = 0; y <= meshSize; y++) {
for (unsigned int x = 0; x <= meshSize; x++) {
float kx = (-(int)meshSize / 2.0f + x) * (2.0f * CUDART_PI_F / patchSize);
float ky = (-(int)meshSize / 2.0f + y) * (2.0f * CUDART_PI_F / patchSize);
float P = sqrtf(phillips(kx, ky, windDir, windSpeed, A, dirDepend));
if (kx == 0.0f && ky == 0.0f) {
P = 0.0f;
}
// float Er = urand()*2.0f-1.0f;
// float Ei = urand()*2.0f-1.0f;
float Er = gauss();
float Ei = gauss();
float h0_re = Er * P * CUDART_SQRT_HALF_F;
float h0_im = Ei * P * CUDART_SQRT_HALF_F;
int i = y * spectrumW + x;
h0[i].x = h0_re;
h0[i].y = h0_im;
}
}
}
////////////////////////////////////////////////////////////////////////////////
//! Run the Cuda kernels
////////////////////////////////////////////////////////////////////////////////
void runCuda() {
size_t num_bytes;
// generate wave spectrum in frequency domain
cudaGenerateSpectrumKernel(d_h0, d_ht, spectrumW, meshSize, meshSize,
animTime, patchSize);
// execute inverse FFT to convert to spatial domain
checkCudaErrors(cufftExecC2C(fftPlan, d_ht, d_ht, CUFFT_INVERSE));
// update heightmap values in vertex buffer
checkCudaErrors(cudaGraphicsMapResources(1, &cuda_heightVB_resource, 0));
checkCudaErrors(cudaGraphicsResourceGetMappedPointer(
(void **)&g_hptr, &num_bytes, cuda_heightVB_resource));
cudaUpdateHeightmapKernel(g_hptr, d_ht, meshSize, meshSize, false);
// calculate slope for shading
checkCudaErrors(cudaGraphicsMapResources(1, &cuda_slopeVB_resource, 0));
checkCudaErrors(cudaGraphicsResourceGetMappedPointer(
(void **)&g_sptr, &num_bytes, cuda_slopeVB_resource));
cudaCalculateSlopeKernel(g_hptr, g_sptr, meshSize, meshSize);
checkCudaErrors(cudaGraphicsUnmapResources(1, &cuda_heightVB_resource, 0));
checkCudaErrors(cudaGraphicsUnmapResources(1, &cuda_slopeVB_resource, 0));
}
void runCudaTest(char *exec_path) {
checkCudaErrors(
cudaMalloc((void **)&g_hptr, meshSize * meshSize * sizeof(float)));
checkCudaErrors(
cudaMalloc((void **)&g_sptr, meshSize * meshSize * sizeof(float2)));
// generate wave spectrum in frequency domain
cudaGenerateSpectrumKernel(d_h0, d_ht, spectrumW, meshSize, meshSize,
animTime, patchSize);
// execute inverse FFT to convert to spatial domain
checkCudaErrors(cufftExecC2C(fftPlan, d_ht, d_ht, CUFFT_INVERSE));
// update heightmap values
cudaUpdateHeightmapKernel(g_hptr, d_ht, meshSize, meshSize, true);
{
float *hptr = (float *)malloc(meshSize * meshSize * sizeof(float));
cudaMemcpy((void *)hptr, (void *)g_hptr,
meshSize * meshSize * sizeof(float), cudaMemcpyDeviceToHost);
sdkDumpBin((void *)hptr, meshSize * meshSize * sizeof(float),
"spatialDomain.bin");
if (!sdkCompareBin2BinFloat("spatialDomain.bin", "ref_spatialDomain.bin",
meshSize * meshSize, MAX_EPSILON, THRESHOLD,
exec_path)) {
g_TotalErrors++;
}
free(hptr);
}
// calculate slope for shading
cudaCalculateSlopeKernel(g_hptr, g_sptr, meshSize, meshSize);
{
float2 *sptr = (float2 *)malloc(meshSize * meshSize * sizeof(float2));
cudaMemcpy((void *)sptr, (void *)g_sptr,
meshSize * meshSize * sizeof(float2), cudaMemcpyDeviceToHost);
sdkDumpBin(sptr, meshSize * meshSize * sizeof(float2), "slopeShading.bin");
if (!sdkCompareBin2BinFloat("slopeShading.bin", "ref_slopeShading.bin",
meshSize * meshSize * 2, MAX_EPSILON, THRESHOLD,
exec_path)) {
g_TotalErrors++;
}
free(sptr);
}
checkCudaErrors(cudaFree(g_hptr));
checkCudaErrors(cudaFree(g_sptr));
}
// void computeFPS()
//{
// frameCount++;
// fpsCount++;
//
// if (fpsCount == fpsLimit) {
// fpsCount = 0;
// }
//}
////////////////////////////////////////////////////////////////////////////////
//! Display callback
////////////////////////////////////////////////////////////////////////////////
void display() {
// run CUDA kernel to generate vertex positions
if (animate) {
runCuda();
}
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// set view matrix
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(translateX, translateY, translateZ);
glRotatef(rotateX, 1.0, 0.0, 0.0);
glRotatef(rotateY, 0.0, 1.0, 0.0);
// render from the vbo
glBindBuffer(GL_ARRAY_BUFFER, posVertexBuffer);
glVertexPointer(4, GL_FLOAT, 0, 0);
glEnableClientState(GL_VERTEX_ARRAY);
glBindBuffer(GL_ARRAY_BUFFER, heightVertexBuffer);
glClientActiveTexture(GL_TEXTURE0);
glTexCoordPointer(1, GL_FLOAT, 0, 0);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glBindBuffer(GL_ARRAY_BUFFER, slopeVertexBuffer);
glClientActiveTexture(GL_TEXTURE1);
glTexCoordPointer(2, GL_FLOAT, 0, 0);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glUseProgram(shaderProg);
// Set default uniform variables parameters for the vertex shader
GLuint uniHeightScale, uniChopiness, uniSize;
uniHeightScale = glGetUniformLocation(shaderProg, "heightScale");
glUniform1f(uniHeightScale, 0.5f);
uniChopiness = glGetUniformLocation(shaderProg, "chopiness");
glUniform1f(uniChopiness, 1.0f);
uniSize = glGetUniformLocation(shaderProg, "size");
glUniform2f(uniSize, (float)meshSize, (float)meshSize);
// Set default uniform variables parameters for the pixel shader
GLuint uniDeepColor, uniShallowColor, uniSkyColor, uniLightDir;
uniDeepColor = glGetUniformLocation(shaderProg, "deepColor");
glUniform4f(uniDeepColor, 0.0f, 0.1f, 0.4f, 1.0f);
uniShallowColor = glGetUniformLocation(shaderProg, "shallowColor");
glUniform4f(uniShallowColor, 0.1f, 0.3f, 0.3f, 1.0f);
uniSkyColor = glGetUniformLocation(shaderProg, "skyColor");
glUniform4f(uniSkyColor, 1.0f, 1.0f, 1.0f, 1.0f);
uniLightDir = glGetUniformLocation(shaderProg, "lightDir");
glUniform3f(uniLightDir, 0.0f, 1.0f, 0.0f);
// end of uniform settings
glColor3f(1.0, 1.0, 1.0);
if (drawPoints) {
glDrawArrays(GL_POINTS, 0, meshSize * meshSize);
} else {
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer);
glPolygonMode(GL_FRONT_AND_BACK, wireFrame ? GL_LINE : GL_FILL);
glDrawElements(GL_TRIANGLE_STRIP, ((meshSize * 2) + 2) * (meshSize - 1),
GL_UNSIGNED_INT, 0);
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
}
glDisableClientState(GL_VERTEX_ARRAY);
glClientActiveTexture(GL_TEXTURE0);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
glClientActiveTexture(GL_TEXTURE1);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
glUseProgram(0);
glutSwapBuffers();
// computeFPS();
}
void timerEvent(int value) {
float time = sdkGetTimerValue(&timer);
if (animate) {
animTime += (time - prevTime) * animationRate;
}
glutPostRedisplay();
prevTime = time;
glutTimerFunc(REFRESH_DELAY, timerEvent, 0);
}
void cleanup() {
sdkDeleteTimer(&timer);
checkCudaErrors(cudaGraphicsUnregisterResource(cuda_heightVB_resource));
checkCudaErrors(cudaGraphicsUnregisterResource(cuda_slopeVB_resource));
deleteVBO(&posVertexBuffer);
deleteVBO(&heightVertexBuffer);
deleteVBO(&slopeVertexBuffer);
checkCudaErrors(cudaFree(d_h0));
checkCudaErrors(cudaFree(d_slope));
checkCudaErrors(cudaFree(d_ht));
free(h_h0);
cufftDestroy(fftPlan);
}
////////////////////////////////////////////////////////////////////////////////
//! Keyboard events handler
////////////////////////////////////////////////////////////////////////////////
void keyboard(unsigned char key, int /*x*/, int /*y*/) {
switch (key) {
case (27):
cleanup();
exit(EXIT_SUCCESS);
case 'w':
wireFrame = !wireFrame;
break;
case 'p':
drawPoints = !drawPoints;
break;
case ' ':
animate = !animate;
break;
}
}
////////////////////////////////////////////////////////////////////////////////
//! Mouse event handlers
////////////////////////////////////////////////////////////////////////////////
void mouse(int button, int state, int x, int y) {
if (state == GLUT_DOWN) {
mouseButtons |= 1 << button;
} else if (state == GLUT_UP) {
mouseButtons = 0;
}
mouseOldX = x;
mouseOldY = y;
glutPostRedisplay();
}
void motion(int x, int y) {
float dx, dy;
dx = (float)(x - mouseOldX);
dy = (float)(y - mouseOldY);
if (mouseButtons == 1) {
rotateX += dy * 0.2f;
rotateY += dx * 0.2f;
} else if (mouseButtons == 2) {
translateX += dx * 0.01f;
translateY -= dy * 0.01f;
} else if (mouseButtons == 4) {
translateZ += dy * 0.01f;
}
mouseOldX = x;
mouseOldY = y;
}
void reshape(int w, int h) {
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(60.0, (double)w / (double)h, 0.1, 10.0);
windowW = w;
windowH = h;
}
////////////////////////////////////////////////////////////////////////////////
//! Initialize GL
////////////////////////////////////////////////////////////////////////////////
bool initGL(int *argc, char **argv) {
// Create GL context
glutInit(argc, argv);
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH);
glutInitWindowSize(windowW, windowH);
glutCreateWindow("CUDA FFT Ocean Simulation");
vertShaderPath = sdkFindFilePath("ocean.vert", argv[0]);
fragShaderPath = sdkFindFilePath("ocean.frag", argv[0]);
if (vertShaderPath == NULL || fragShaderPath == NULL) {
fprintf(stderr, "Error unable to find GLSL vertex and fragment shaders!\n");
exit(EXIT_FAILURE);
}
// initialize necessary OpenGL extensions
if (!isGLVersionSupported(2, 0)) {
fprintf(stderr, "ERROR: Support for necessary OpenGL extensions missing.");
fflush(stderr);
return false;
}
if (!areGLExtensionsSupported(
"GL_ARB_vertex_buffer_object GL_ARB_pixel_buffer_object")) {
fprintf(stderr, "Error: failed to get minimal extensions for demo\n");
fprintf(stderr, "This sample requires:\n");
fprintf(stderr, " OpenGL version 1.5\n");
fprintf(stderr, " GL_ARB_vertex_buffer_object\n");
fprintf(stderr, " GL_ARB_pixel_buffer_object\n");
cleanup();
exit(EXIT_FAILURE);
}
// default initialization
glClearColor(0.0, 0.0, 0.0, 1.0);
glEnable(GL_DEPTH_TEST);
// load shader
shaderProg = loadGLSLProgram(vertShaderPath, fragShaderPath);
SDK_CHECK_ERROR_GL();
return true;
}
////////////////////////////////////////////////////////////////////////////////
//! Create VBO
////////////////////////////////////////////////////////////////////////////////
void createVBO(GLuint *vbo, int size) {
// create buffer object
glGenBuffers(1, vbo);
glBindBuffer(GL_ARRAY_BUFFER, *vbo);
glBufferData(GL_ARRAY_BUFFER, size, 0, GL_DYNAMIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
SDK_CHECK_ERROR_GL();
}
////////////////////////////////////////////////////////////////////////////////
//! Delete VBO
////////////////////////////////////////////////////////////////////////////////
void deleteVBO(GLuint *vbo) {
glDeleteBuffers(1, vbo);
*vbo = 0;
}
// create index buffer for rendering quad mesh
void createMeshIndexBuffer(GLuint *id, int w, int h) {
int size = ((w * 2) + 2) * (h - 1) * sizeof(GLuint);
// create index buffer
glGenBuffers(1, id);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, *id);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, size, 0, GL_STATIC_DRAW);
// fill with indices for rendering mesh as triangle strips
GLuint *indices =
(GLuint *)glMapBuffer(GL_ELEMENT_ARRAY_BUFFER, GL_WRITE_ONLY);
if (!indices) {
return;
}
for (int y = 0; y < h - 1; y++) {
for (int x = 0; x < w; x++) {
*indices++ = y * w + x;
*indices++ = (y + 1) * w + x;
}
// start new strip with degenerate triangle
*indices++ = (y + 1) * w + (w - 1);
*indices++ = (y + 1) * w;
}
glUnmapBuffer(GL_ELEMENT_ARRAY_BUFFER);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
}
// create fixed vertex buffer to store mesh vertices
void createMeshPositionVBO(GLuint *id, int w, int h) {
createVBO(id, w * h * 4 * sizeof(float));
glBindBuffer(GL_ARRAY_BUFFER, *id);
float *pos = (float *)glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY);
if (!pos) {
return;
}
for (int y = 0; y < h; y++) {
for (int x = 0; x < w; x++) {
float u = x / (float)(w - 1);
float v = y / (float)(h - 1);
*pos++ = u * 2.0f - 1.0f;
*pos++ = 0.0f;
*pos++ = v * 2.0f - 1.0f;
*pos++ = 1.0f;
}
}
glUnmapBuffer(GL_ARRAY_BUFFER);
glBindBuffer(GL_ARRAY_BUFFER, 0);
}
// Attach shader to a program
int attachShader(GLuint prg, GLenum type, const char *name) {
GLuint shader;
FILE *fp;
int size, compiled;
char *src;
fp = fopen(name, "rb");
if (!fp) {
return 0;
}
fseek(fp, 0, SEEK_END);
size = ftell(fp);
src = (char *)malloc(size);
fseek(fp, 0, SEEK_SET);
fread(src, sizeof(char), size, fp);
fclose(fp);
shader = glCreateShader(type);
glShaderSource(shader, 1, (const char **)&src, (const GLint *)&size);
glCompileShader(shader);
glGetShaderiv(shader, GL_COMPILE_STATUS, (GLint *)&compiled);
if (!compiled) {
char log[2048];
int len;
glGetShaderInfoLog(shader, 2048, (GLsizei *)&len, log);
printf("Info log: %s\n", log);
glDeleteShader(shader);
return 0;
}
free(src);
glAttachShader(prg, shader);
glDeleteShader(shader);
return 1;
}
// Create shader program from vertex shader and fragment shader files
GLuint loadGLSLProgram(const char *vertFileName, const char *fragFileName) {
GLint linked;
GLuint program;
program = glCreateProgram();
if (!attachShader(program, GL_VERTEX_SHADER, vertFileName)) {
glDeleteProgram(program);
fprintf(stderr, "Couldn't attach vertex shader from file %s\n",
vertFileName);
return 0;
}
if (!attachShader(program, GL_FRAGMENT_SHADER, fragFileName)) {
glDeleteProgram(program);
fprintf(stderr, "Couldn't attach fragment shader from file %s\n",
fragFileName);
return 0;
}
glLinkProgram(program);
glGetProgramiv(program, GL_LINK_STATUS, &linked);
if (!linked) {
glDeleteProgram(program);
char temp[256];
glGetProgramInfoLog(program, 256, 0, temp);
fprintf(stderr, "Failed to link program: %s\n", temp);
return 0;
}
return program;
}