Ich versuche, Histogramm eines Bildes mit OPENGL zu berechnen. Ich habe einen Post darüber gelesen, aber ich bekomme immer noch Fehler. Mein Histogrammpuffer gibt immer Nullen zurück. noch einige Kleinigkeiten, die ich gelesen habe:Histogramm in OPENGL berechnen
Luminance histogram calculation in GPU-android opengl es 3.0
Mein Code:
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <vector>
// Include GLEW
#include <GL/glew.h>
// Include GLFW
#include <GLFW/glfw3.h>
GLFWwindow* window;
// Include GLM
#include <glm/glm.hpp>
using namespace glm;
#include <SOIL.h>
// Shader sources
const GLchar* vertexSource = "\n"
"#version 330 core\n"
"attribute vec3 inPosition;\n"
"void main()\n"
"{\n"
" float x = inPosition.x;\n"
"\n"
" gl_Position = vec4(\n"
" -1.0 + ((x) * 0.0078125),\n"
" -1,\n"
" 0.0,\n"
" 1.0\n"
" );\n"
"}\n";
const GLchar* fragmentSource = "\n"
"#version 330 core\n"
"out vec4 outputColor;\n"
"void main()\n"
"{\n"
" outputColor = vec4(1.0, 1.0, 1.0, 1.0);\n"
"}\n";
void CheckStatus(GLuint obj)
{
GLint status = GL_FALSE, len = 10;
if(glIsShader(obj)) glGetShaderiv(obj, GL_COMPILE_STATUS, &status);
if(glIsProgram(obj)) glGetProgramiv(obj, GL_LINK_STATUS, &status);
if(status == GL_TRUE) return;
if(glIsShader(obj)) glGetShaderiv(obj, GL_INFO_LOG_LENGTH, &len);
if(glIsProgram(obj)) glGetProgramiv(obj, GL_INFO_LOG_LENGTH, &len);
std::vector<char> log(len, 'X');
if(glIsShader(obj)) glGetShaderInfoLog(obj, len, NULL, &log[0]);
if(glIsProgram(obj)) glGetProgramInfoLog(obj, len, NULL, &log[0]);
std::cerr << &log[0] << std::endl;
exit(-1);
}
GLfloat buffer[256];
GLuint hist[256];
float _image[512*512*3];
int main()
{
// Initialise GLFW
if(!glfwInit())
{
fprintf(stderr, "Failed to initialize GLFW\n");
getchar();
return -1;
}
glfwWindowHint(GLFW_SAMPLES, 4);
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // To make MacOS happy; should not be needed
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
int width, height;
unsigned char* image = SOIL_load_image("sample_gray.bmp", &width, &height, 0, SOIL_LOAD_RGB);
unsigned char image_gray[width * height];
printf("%d\t%d\n", width, height);
for (int i = 0; i < width * height; ++i)
{
image_gray[i] = image[i * 3];
_image[i * 3] = image[i * 3];
_image[i * 3 + 1] = image[i * 3 + 1];
_image[i * 3 + 2] = image[i * 3 + 2];
}
for (int i = 0; i < width * height; ++i)
{
hist[image_gray[i]]++;
}
// Open a window and create its OpenGL context
window = glfwCreateWindow(width, height, "Basic", 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");
getchar();
glfwTerminate();
return -1;
}
glfwMakeContextCurrent(window);
// Initialize GLEW
glewExperimental = true; // Needed for core profile
if (glewInit() != GLEW_OK) {
fprintf(stderr, "Failed to initialize GLEW\n");
getchar();
glfwTerminate();
return -1;
}
// 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, 0.0f, 0.0f);
GLuint vbo;
glGenBuffers(1, &vbo);
glBindBuffer(GL_ARRAY_BUFFER, vbo);
GLuint num_input_data = width * height;
/* Upload data */
glBufferData(GL_ARRAY_BUFFER, num_input_data * sizeof(float) * 3, _image, GL_STATIC_DRAW);
GLuint vertexShader, fragmentShader, shaderProgram;
// Create and compile the vertex shader
vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &vertexSource, NULL);
glCompileShader(vertexShader);
CheckStatus(vertexShader);
// Create and compile the fragment shader
fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &fragmentSource, NULL);
glCompileShader(fragmentShader);
CheckStatus(fragmentShader);
// Link the vertex and fragment shader into a shader program
shaderProgram = glCreateProgram();
glAttachShader(shaderProgram, vertexShader);
glAttachShader(shaderProgram, fragmentShader);
glBindFragDataLocation(shaderProgram, 0, "outputColor");
glLinkProgram(shaderProgram);
CheckStatus(shaderProgram);
glUseProgram(shaderProgram);
// Specify the layout of the vertex data
GLint posAttrib = glGetAttribLocation(shaderProgram, "inPosition");
glEnableVertexAttribArray(posAttrib);
glVertexAttribPointer(posAttrib, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(GLfloat), 0);
GLuint tex;
GLuint fbo;
glGenTextures(1, &tex);
glBindFramebuffer(GL_FRAMEBUFFER, fbo);
glGenFramebuffers(1, &fbo);
glActiveTexture(GL_TEXTURE0);
// glBindTexture(GL_TEXTURE_2D, tex);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexStorage2D(GL_TEXTURE_2D, 1, GL_R32F, 256, 1);
// glBindTexture(GL_TEXTURE_2D, 0);
glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, tex, 0);
/* Clear buffer */
glClearColor(1.0, 0.0, 0.0, 1.0);
glClear(GL_COLOR_BUFFER_BIT);
glBlendEquation(GL_FUNC_ADD);
glBlendFunc(GL_ONE, GL_ONE);
glEnable(GL_BLEND);
/* Init viewport */
glViewport(0, 0, 256, 1);
glUseProgram(shaderProgram);
/* Draw */
glDrawArrays(GL_POINTS, 0, num_input_data);
glReadPixels(0, 0, 256, 1, GL_RED, GL_FLOAT, buffer);
for (int i = 0; i < 256; ++i)
{
printf("%d\t%f\t%d\n", i, buffer[i], hist[i]);
}
}
Könnte jemand mir helfen, danke im voraus.
ich meinen Code aktualisiert haben, es funktioniert jetzt: D
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <vector>
// Include GLEW
#include <GL/glew.h>
// Include GLFW
#include <GLFW/glfw3.h>
GLFWwindow* window;
// Include GLM
#include <glm/glm.hpp>
using namespace glm;
#include <SOIL.h>
// Shader sources
const GLchar* vertexSource = "\n"
"#version 330 core\n"
"in vec3 inPosition;\n"
"void main()\n"
"{\n"
" float x = inPosition.x;\n"
"\n"
" gl_Position = vec4(\n"
" -1.0 + ((x + 1) * 0.0078125),\n"
" 0.0,\n"
" 0.0,\n"
" 1.0\n"
" );\n"
"}\n";
const GLchar* fragmentSource = "\n"
"#version 330 core\n"
"out vec4 outputColor;\n"
"void main()\n"
"{\n"
" outputColor = vec4(1.0, 1.0, 1.0, 1.0);\n"
"}\n";
void CheckStatus(GLuint obj)
{
GLint status = GL_FALSE, len = 10;
if(glIsShader(obj)) glGetShaderiv(obj, GL_COMPILE_STATUS, &status);
if(glIsProgram(obj)) glGetProgramiv(obj, GL_LINK_STATUS, &status);
if(status == GL_TRUE) return;
if(glIsShader(obj)) glGetShaderiv(obj, GL_INFO_LOG_LENGTH, &len);
if(glIsProgram(obj)) glGetProgramiv(obj, GL_INFO_LOG_LENGTH, &len);
std::vector<char> log(len, 'X');
if(glIsShader(obj)) glGetShaderInfoLog(obj, len, NULL, &log[0]);
if(glIsProgram(obj)) glGetProgramInfoLog(obj, len, NULL, &log[0]);
std::cerr << &log[0] << std::endl;
exit(-1);
}
void _check_gl_error(int line)
{
GLenum err (glGetError());
while(err!=GL_NO_ERROR)
{
std::string error;
switch(err)
{
case GL_INVALID_OPERATION: error="INVALID_OPERATION"; break;
case GL_INVALID_ENUM: error="INVALID_ENUM"; break;
case GL_INVALID_VALUE: error="INVALID_VALUE"; break;
case GL_OUT_OF_MEMORY: error="OUT_OF_MEMORY"; break;
case GL_INVALID_FRAMEBUFFER_OPERATION: error="INVALID_FRAMEBUFFER_OPERATION"; break;
}
std::cerr << "GL_" << error.c_str() <<":"<<line<<std::endl;
err=glGetError();
}
}
GLfloat buffer[256];
GLuint hist[256];
float _image[512*512*3];
int main()
{
// Initialise GLFW
if(!glfwInit())
{
fprintf(stderr, "Failed to initialize GLFW\n");
getchar();
return -1;
}
glfwWindowHint(GLFW_SAMPLES, 4);
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // To make MacOS happy; should not be needed
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
int width, height;
unsigned char* image = SOIL_load_image("sample_gray.bmp", &width, &height, 0, SOIL_LOAD_RGB);
unsigned char* image_gray = new unsigned char[width * height];
printf("%d\t%d\n", width, height);
for (int i = 0; i < width * height; ++i)
{
image_gray[i] = image[i * 3];
_image[i * 3] = image[i * 3];
_image[i * 3 + 1] = image[i * 3 + 1];
_image[i * 3 + 2] = image[i * 3 + 2];
}
for (int i = 0; i < width * height; ++i)
{
hist[image_gray[i]]++;
}
// Open a window and create its OpenGL context
window = glfwCreateWindow(width, height, "Basic", 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");
getchar();
glfwTerminate();
return -1;
}
glfwMakeContextCurrent(window);
// Initialize GLEW
glewExperimental = true; // Needed for core profile
if (glewInit() != GLEW_OK) {
fprintf(stderr, "Failed to initialize GLEW\n");
getchar();
glfwTerminate();
return -1;
}
_check_gl_error(__LINE__);
// 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, 0.0f, 0.0f);
GLuint vao;
glGenVertexArrays(1, &vao);
glBindVertexArray(vao);
GLuint vbo;
glGenBuffers(1, &vbo);
glBindBuffer(GL_ARRAY_BUFFER, vbo);
GLuint num_input_data = width * height;
/* Upload data */
glBufferData(GL_ARRAY_BUFFER, num_input_data * sizeof(float) * 3, _image, GL_STATIC_DRAW);
GLuint vertexShader, fragmentShader, shaderProgram;
// Create and compile the vertex shader
vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &vertexSource, NULL);
glCompileShader(vertexShader);
CheckStatus(vertexShader);
// Create and compile the fragment shader
fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &fragmentSource, NULL);
glCompileShader(fragmentShader);
CheckStatus(fragmentShader);
// Link the vertex and fragment shader into a shader program
shaderProgram = glCreateProgram();
glAttachShader(shaderProgram, vertexShader);
glAttachShader(shaderProgram, fragmentShader);
glBindFragDataLocation(shaderProgram, 0, "outputColor");
glLinkProgram(shaderProgram);
CheckStatus(shaderProgram);
glUseProgram(shaderProgram);
// Specify the layout of the vertex data
GLint posAttrib = glGetAttribLocation(shaderProgram, "inPosition");
glEnableVertexAttribArray(posAttrib);
glVertexAttribPointer(posAttrib, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(GLfloat), 0);
GLuint tex;
GLuint fbo;
glGenFramebuffers(1, &fbo);
glBindFramebuffer(GL_FRAMEBUFFER, fbo);
glGenTextures(1, &tex);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, tex);
glTexImage2D(GL_TEXTURE_2D, 0, GL_R32F, 256, 1, 0, GL_RED, GL_FLOAT, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
// glTexStorage2D(GL_TEXTURE_2D, 1, GL_R32F, 256, 1);
glBindTexture(GL_TEXTURE_2D, 0);
glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, tex, 0);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
_check_gl_error(__LINE__);
glBindFramebuffer(GL_FRAMEBUFFER, fbo);
/* Clear buffer */
glClearColor(0.0, 0.0, 0.0, 1.0);
glClear(GL_COLOR_BUFFER_BIT);
glBlendEquation(GL_FUNC_ADD);
glBlendFunc(GL_ONE, GL_ONE);
glEnable(GL_BLEND);
_check_gl_error(__LINE__);
/* Init viewport */
glViewport(0, 0, 256, 1);
glUseProgram(shaderProgram);
/* Draw */
glDrawArrays(GL_POINTS, 0, num_input_data);
glReadPixels(0, 0, 256, 1, GL_RED, GL_FLOAT, buffer);
_check_gl_error(__LINE__);
for (int i = 0; i < 256; ++i)
{
printf("%d\t%f\t%d\n", i, buffer[i], hist[i]);
}
free(image_gray);
}
Besonderer Dank für Ihre Begeisterung @Vallentin!
Das erste, was ich sehe, ist, dass Sie 'fbo' binden, bevor Sie es erzeugen. Zweitens: Ihre 'CheckStatus'-Methode funktioniert nur, wenn es kein Shader-Objekt und kein Shader-Programm mit derselben ID gibt. Alle Handles sind nur vorzeichenlose Integer, und es ist durchaus zulässig, dass eine OpenGL-Implementierung Ihnen ein Shader-Objekt 0 und ein Shader-Programm-Objekt 0 liefert. In diesem Fall würde Ihre Methode sowohl den Verbindungsstatus als auch den Kompilierungsstatus abfragen. – BDL
@ BDL, Danke. Ich habe meinen Code unten aktualisiert. Kannst du mir helfen, es noch einmal zu überprüfen? –