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// Include standard headers
#include <stdio.h>
#include <stdlib.h>
#include <string>
#include <fstream>
#include <glew.h>
#include <vector>
// Include GLFW
#include <GLFW/glfw3.h>
GLuint LoadShaders(const char * vertex_file_path,const char * fragment_file_path){
// Create the shaders
GLuint VertexShaderID = glCreateShader(GL_VERTEX_SHADER);
GLuint FragmentShaderID = glCreateShader(GL_FRAGMENT_SHADER);
// Read the Vertex Shader code from the file
std::string VertexShaderCode;
std::ifstream VertexShaderStream(vertex_file_path, std::ios::in);
if(VertexShaderStream.is_open())
{
std::string Line = "";
while(getline(VertexShaderStream, Line))
VertexShaderCode += "\n" + Line;
VertexShaderStream.close();
}
// Read the Fragment Shader code from the file
std::string FragmentShaderCode;
std::ifstream FragmentShaderStream(fragment_file_path, std::ios::in);
if(FragmentShaderStream.is_open()){
std::string Line = "";
while(getline(FragmentShaderStream, Line))
FragmentShaderCode += "\n" + Line;
FragmentShaderStream.close();
}
GLint Result = GL_FALSE;
int InfoLogLength;
// Compile Vertex Shader
printf("Compiling shader : %s\n", vertex_file_path);
char const * VertexSourcePointer = VertexShaderCode.c_str();
glShaderSource(VertexShaderID, 1, &VertexSourcePointer , NULL);
glCompileShader(VertexShaderID);
// Check Vertex Shader
glGetShaderiv(VertexShaderID, GL_COMPILE_STATUS, &Result);
glGetShaderiv(VertexShaderID, GL_INFO_LOG_LENGTH, &InfoLogLength);
std::vector<char> VertexShaderErrorMessage(InfoLogLength);
glGetShaderInfoLog(VertexShaderID, InfoLogLength, NULL, &VertexShaderErrorMessage[0]);
fprintf(stdout, "%s\n", &VertexShaderErrorMessage[0]);
// Compile Fragment Shader
printf("Compiling shader : %s\n", fragment_file_path);
char const * FragmentSourcePointer = FragmentShaderCode.c_str();
glShaderSource(FragmentShaderID, 1, &FragmentSourcePointer , NULL);
glCompileShader(FragmentShaderID);
// Check Fragment Shader
glGetShaderiv(FragmentShaderID, GL_COMPILE_STATUS, &Result);
glGetShaderiv(FragmentShaderID, GL_INFO_LOG_LENGTH, &InfoLogLength);
std::vector<char> FragmentShaderErrorMessage(InfoLogLength);
glGetShaderInfoLog(FragmentShaderID, InfoLogLength, NULL, &FragmentShaderErrorMessage[0]);
fprintf(stdout, "%s\n", &FragmentShaderErrorMessage[0]);
// Link the program
fprintf(stdout, "Linking program\n");
GLuint ProgramID = glCreateProgram();
glAttachShader(ProgramID, VertexShaderID);
glAttachShader(ProgramID, FragmentShaderID);
glLinkProgram(ProgramID);
// Check the program
glGetProgramiv(ProgramID, GL_LINK_STATUS, &Result);
glGetProgramiv(ProgramID, GL_INFO_LOG_LENGTH, &InfoLogLength);
std::vector<char> ProgramErrorMessage( std::max(InfoLogLength, int(1)) );
glGetProgramInfoLog(ProgramID, InfoLogLength, NULL, &ProgramErrorMessage[0]);
fprintf(stdout, "%s\n", &ProgramErrorMessage[0]);
glDeleteShader(VertexShaderID);
glDeleteShader(FragmentShaderID);
return ProgramID;
}
GLFWwindow* window;
int main( void )
{
// Initialise GLFW
if( !glfwInit() )
{
fprintf( stderr, "Failed to initialize GLFW\n" );
return -1;
}
glfwWindowHint(GLFW_SAMPLES, 4);
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
// Open a window and create its OpenGL context
window = glfwCreateWindow( 1024, 768, "Tutorial 01", NULL, NULL);
if( window == NULL ){
fprintf( stderr, "Failed to open GLFW window. If you have an Intel GPU, they are not 3.3 compatible. Try the 2.1 version of the tutorials.\n" );
glfwTerminate();
return -1;
}
glfwMakeContextCurrent(window);
if (glewInit() != GLEW_OK) {
fprintf(stderr, "Failed to initialize GLEW\n");
return -1;
}
GLuint abufferTexID, abufferCounterTexID, adepthbufferTexID;
glGenTextures(1, &abufferTexID);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexImage3D(GL_TEXTURE_2D_ARRAY, 0, GL_RGBA32F, 1024, 768, 16, 0, GL_RGBA, GL_FLOAT, 0);
glBindImageTextureEXT(0, abufferTexID, 0, true, 0, GL_READ_WRITE, GL_RGBA32F);
glGenTextures(1, &abufferCounterTexID);
glBindTexture(GL_TEXTURE_2D, abufferCounterTexID);
// Set filter
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
//Texture creation
//Uses GL_R32F instead of GL_R32I that is not working in R257.15
glTexImage2D(GL_TEXTURE_2D, 0, GL_R32F, 1024, 768, 0, GL_RED, GL_FLOAT, 0);
glBindImageTextureEXT(1, abufferCounterTexID, 0, false, 0, GL_READ_WRITE, GL_R32UI);
glGenTextures(1, &adepthbufferTexID);
glBindTexture(GL_TEXTURE_2D, adepthbufferTexID);
// Set filter
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
//Texture creation
//Uses GL_R32F instead of GL_R32I that is not working in R257.15
glTexImage3D(GL_TEXTURE_2D_ARRAY, 0, GL_R32F, 1024, 768, 16, 0, GL_RED, GL_FLOAT, 0);
glBindImageTextureEXT(1, adepthbufferTexID, 0, true, 0, GL_READ_WRITE, GL_R32F);
GLuint VertexArrayID;
glGenVertexArrays(1, &VertexArrayID);
glBindVertexArray(VertexArrayID);
// An array of 3 vectors which represents 3 vertices
static const GLfloat g_vertex_buffer_data2[] = {
-1.0f, -1.f, 0.f,
1.f, -1.f, 0.f,
1.f, 1.f, 0.f,
-1.f, 1.f, 0.f
};
static const GLfloat g_vertex_buffer_data[] = {
-1.0f, -1.0f, 0.0f,
1.0f, -1.0f, 0.0f,
0.0f, 1.0f, 0.0f,
};
// This will identify our vertex buffer
GLuint vertexbuffer, vertexbuffer2;
// Generate 1 buffer, put the resulting identifier in vertexbuffer
glGenBuffers(1, &vertexbuffer);
// The following commands will talk about our 'vertexbuffer' buffer
glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
// Give our vertices to OpenGL.
glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertex_buffer_data), g_vertex_buffer_data, GL_STATIC_DRAW);
glGenBuffers(1, &vertexbuffer2);
glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer2);
glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertex_buffer_data2), g_vertex_buffer_data2, GL_STATIC_DRAW);
// Create and compile our GLSL program from the shaders
GLuint programID = LoadShaders( "SimpleVertexShader.vertexshader", "SimpleFragmentShader.fragmentshader" );
GLuint programID2 = LoadShaders("SimpleVertexShader.vertexshader","ClearABuffer.fragmentshader");
GLuint abufferLocation = glGetUniformLocation(programID, "abufferImg");
GLuint abufferCounterLocation = glGetUniformLocation(programID, "abufferCounterImg");
GLuint adepthbufferLocation = glGetUniformLocation(programID, "adepthbufferImg");
GLuint abufferLocation2 = glGetUniformLocation(programID2, "abufferImg");
GLuint abufferCounterLocation2 = glGetUniformLocation(programID2, "abufferCounterImg");
GLuint adepthbufferLocation2 = glGetUniformLocation(programID2, "adepthbufferImg");
// Initialize GLEW
// Ensure we can capture the escape key being pressed below
glfwSetInputMode(window, GLFW_STICKY_KEYS, GL_TRUE);
// Dark blue background
glClearColor(0.0f, 0.0f, 0.4f, 0.0f);
do{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnableVertexAttribArray(0);
glVertexAttribPointer(
0, // attribute 0. No particular reason for 0, but must match the layout in the shader.
3, // size
GL_FLOAT, // type
GL_FALSE, // normalized?
0, // stride
(void*)0 // array buffer offset
);
glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer2);
glUseProgram(programID2);
glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
glUseProgram(programID);
// Draw the triangle !
glDrawArrays(GL_TRIANGLES, 0, 3); // Starting from vertex 0; 3 vertices total -> 1 triangle
glDisableVertexAttribArray(0);
glfwSwapBuffers(window);
glfwPollEvents();
} // Check if the ESC key was pressed or the window was closed
while( glfwGetKey(window, GLFW_KEY_ESCAPE ) != GLFW_PRESS &&
glfwWindowShouldClose(window) == 0 );
// Close OpenGL window and terminate GLFW
glfwTerminate();
return 0;
} |
