static GLboolean renderToPixelBuffer(GLubyte* pixels, const GLint width, const GLint height)
{
GLint x, y, index;
GLfloat pixelColor[4];
// Generate the ray directions depending on FOV, width and height.
if (!glusRaytracePerspectivef(g_directionBuffer, 0, 30.0f, width, height))
{
printf("Error: Could not create direction buffer.\n");
return GLUS_FALSE;
}
// Rendering only once, so direction buffer can be overwritten.
glusRaytraceLookAtf(g_positionBuffer, g_directionBuffer, g_directionBuffer, 0, width, height, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f);
// Ray marching over all pixels
for (y = 0; y < HEIGHT; y++)
{
for (x = 0; x < WIDTH; x++)
{
index = (x + y * WIDTH);
march(pixelColor, &g_positionBuffer[index * 4], &g_directionBuffer[index * 3], 0);
// Resolve to pixel buffer, which is used for the texture.
pixels[index * BYTES_PER_PIXEL + 0] = (GLubyte)(glusMathMinf(1.0f, pixelColor[0]) * 255.0f);
pixels[index * BYTES_PER_PIXEL + 1] = (GLubyte)(glusMathMinf(1.0f, pixelColor[1]) * 255.0f);
pixels[index * BYTES_PER_PIXEL + 2] = (GLubyte)(glusMathMinf(1.0f, pixelColor[2]) * 255.0f);
}
}
return GLUS_TRUE;
}
GLUSboolean init(GLUSvoid)
{
GLUStextfile vertexSource;
GLUStextfile fragmentSource;
GLUStextfile computeSource;
glusLoadTextFile("../Example30/shader/fullscreen.vert.glsl", &vertexSource);
glusLoadTextFile("../Example30/shader/texture.frag.glsl", &fragmentSource);
glusBuildProgramFromSource(&g_program, (const GLchar**)&vertexSource.text, 0, 0, 0, (const GLchar**)&fragmentSource.text);
glusDestroyTextFile(&vertexSource);
glusDestroyTextFile(&fragmentSource);
glusLoadTextFile("../Example30/shader/raytrace.comp.glsl", &computeSource);
glusBuildComputeProgramFromSource(&g_computeProgram, (const GLchar**)&computeSource.text);
glusDestroyTextFile(&computeSource);
//
// Retrieve the uniform locations in the program.
g_textureLocation = glGetUniformLocation(g_program.program, "u_texture");
//
// Generate and bind a texture.
glGenTextures(1, &g_texture);
glBindTexture(GL_TEXTURE_2D, g_texture);
// Create an empty image.
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, g_imageWidth, g_imageHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
// Setting the texture parameters.
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glBindTexture(GL_TEXTURE_2D, 0);
//
//
glUseProgram(g_program.program);
glGenVertexArrays(1, &g_vao);
glBindVertexArray(g_vao);
//
// Also bind created texture ...
glBindTexture(GL_TEXTURE_2D, g_texture);
// ... and bind this texture as an image, as we will write to it. see binding = 0 in shader.
glBindImageTexture(0, g_texture, 0, GL_FALSE, 0, GL_WRITE_ONLY, GL_RGBA8);
// ... and as this is texture number 0, bind the uniform to the program.
glUniform1i(g_textureLocation, 0);
//
//
glUseProgram(g_computeProgram.program);
//
// Generate the ray directions depending on FOV, width and height.
if (!glusRaytracePerspectivef(g_directionBuffer, PADDING, 30.0f, WIDTH, HEIGHT))
{
printf("Error: Could not create direction buffer.\n");
return GLUS_FALSE;
}
// Compute shader will use these textures just for input.
glusRaytraceLookAtf(g_positionBuffer, g_directionBuffer, g_directionBuffer, PADDING, WIDTH, HEIGHT, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f);
//
// Buffers with the initial ray position and direction.
//
glGenBuffers(1, &g_directionSSBO);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, g_directionSSBO);
glBufferData(GL_SHADER_STORAGE_BUFFER, WIDTH * HEIGHT * (3 + PADDING) * sizeof(GLfloat), g_directionBuffer, GL_STATIC_READ);
// see binding = 1 in the shader
glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 1, g_directionSSBO);
//
glGenBuffers(1, &g_positionSSBO);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, g_positionSSBO);
glBufferData(GL_SHADER_STORAGE_BUFFER, WIDTH * HEIGHT * 4 * sizeof(GLfloat), g_positionBuffer, GL_STATIC_READ);
// see binding = 2 in the shader
glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 2, g_positionSSBO);
return GLUS_TRUE;
}
GLUSboolean init(GLUSvoid)
{
GLint i;
GLUStextfile vertexSource;
GLUStextfile fragmentSource;
GLUStextfile computeSource;
glusFileLoadText("shader/fullscreen.vert.glsl", &vertexSource);
glusFileLoadText("shader/texture.frag.glsl", &fragmentSource);
glusProgramBuildFromSource(&g_program, (const GLchar**)&vertexSource.text, 0, 0, 0, (const GLchar**)&fragmentSource.text);
glusFileDestroyText(&vertexSource);
glusFileDestroyText(&fragmentSource);
glusFileLoadText("shader/raytrace.comp.glsl", &computeSource);
glusProgramBuildComputeFromSource(&g_computeProgram, (const GLchar**)&computeSource.text);
glusFileDestroyText(&computeSource);
//
// Retrieve the uniform locations in the program.
g_textureLocation = glGetUniformLocation(g_program.program, "u_texture");
//
// Generate and bind a texture.
glGenTextures(1, &g_texture);
glBindTexture(GL_TEXTURE_2D, g_texture);
// Create an empty image.
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, WIDTH, HEIGHT, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
// Setting the texture parameters.
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glBindTexture(GL_TEXTURE_2D, 0);
//
//
glUseProgram(g_program.program);
glGenVertexArrays(1, &g_vao);
glBindVertexArray(g_vao);
//
// Also bind created texture ...
glBindTexture(GL_TEXTURE_2D, g_texture);
// ... and bind this texture as an image, as we will write to it. see binding = 0 in shader.
glBindImageTexture(0, g_texture, 0, GL_FALSE, 0, GL_WRITE_ONLY, GL_RGBA8);
// ... and as this is texture number 0, bind the uniform to the program.
glUniform1i(g_textureLocation, 0);
//
//
glUseProgram(g_computeProgram.program);
//
printf("Preparing buffers ... ");
// Generate the ray directions depending on FOV, width and height.
if (!glusRaytracePerspectivef(g_directionBuffer, DIRECTION_BUFFER_PADDING, 30.0f, WIDTH, HEIGHT))
{
printf("failed!\n");
printf("Error: Could not create direction buffer.\n");
return GLUS_FALSE;
}
// Compute shader will use these textures just for input.
glusRaytraceLookAtf(g_positionBuffer, g_directionBuffer, g_directionBuffer, DIRECTION_BUFFER_PADDING, WIDTH, HEIGHT, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f);
for (i = 0; i < WIDTH * HEIGHT * STACK_NODE_FLOATS * NUM_STACK_NODES; i++)
{
g_stackBuffer[i] = 0.0f;
}
printf("done!\n");
//
// Buffers with the initial ray position and direction.
//
glGenBuffers(1, &g_directionSSBO);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, g_directionSSBO);
glBufferData(GL_SHADER_STORAGE_BUFFER, WIDTH * HEIGHT * (3 + DIRECTION_BUFFER_PADDING) * sizeof(GLfloat), g_directionBuffer, GL_STATIC_DRAW);
// see binding = 1 in the shader
glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 1, g_directionSSBO);
//
glGenBuffers(1, &g_positionSSBO);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, g_positionSSBO);
glBufferData(GL_SHADER_STORAGE_BUFFER, WIDTH * HEIGHT * 4 * sizeof(GLfloat), g_positionBuffer, GL_STATIC_DRAW);
// see binding = 2 in the shader
glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 2, g_positionSSBO);
//
glGenBuffers(1, &g_stackSSBO);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, g_stackSSBO);
glBufferData(GL_SHADER_STORAGE_BUFFER, WIDTH * HEIGHT * STACK_NODE_FLOATS * NUM_STACK_NODES * sizeof(GLfloat), g_stackBuffer, GL_STATIC_DRAW);
// see binding = 3 in the shader
glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 3, g_stackSSBO);
//
glGenBuffers(1, &g_sphereSSBO);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, g_sphereSSBO);
glBufferData(GL_SHADER_STORAGE_BUFFER, NUM_SPHERES * sizeof(Sphere), g_sphereBuffer, GL_STATIC_DRAW);
// see binding = 4 in the shader
glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 4, g_sphereSSBO);
//
glGenBuffers(1, &g_pointLightSSBO);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, g_pointLightSSBO);
glBufferData(GL_SHADER_STORAGE_BUFFER, NUM_LIGHTS * sizeof(PointLight), g_lightBuffer, GL_STATIC_DRAW);
// see binding = 5 in the shader
glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 5, g_pointLightSSBO);
//
return GLUS_TRUE;
}