OpenGL texturierten Würfel Tutorial - Beispielcode nicht funktioniert

Question

Ich habe hier durch die opengl Tutorials gegangen: http://www.opengl-tutorial.org/beginners-tutorials/tutorial-5-a-textured-cube/

Die Website liefert Ihnen abgeschlossen Versionen jedes Tutorial, so dass Sie mit Ihrem eigenen Implementierung vergleichen. Leider scheint Tutorial 5 für mich nicht zu funktionieren (weder meine Implementierung noch die zur Verfügung gestellte). Ich habe Bilder davon beigefügt, wie ich glaube, dass es aussehen sollte und was ich bekomme, wenn ich die ausführbare Datei ausführe, die aus ihrem Code generiert wurde.

Ich benutze ein 2015 MacBook Pro mit Windows 10, kompilieren in VS2015, mit Intels Iris 6100 integrierte GPU.

Der folgende Code ist aus dem Tutorial.

// Include standard headers 
#include <stdio.h> 
#include <stdlib.h> 

// Include GLEW 
#include <GL/glew.h> 

// Include GLFW 
#include <glfw3.h> 
GLFWwindow* window; 

// Include GLM 
#include <glm/glm.hpp> 
#include <glm/gtc/matrix_transform.hpp> 
using namespace glm; 

#include <common/shader.hpp> 
#include <common/texture.hpp> 

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, 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); 

// Open a window and create its OpenGL context 
window = glfwCreateWindow(1024, 768, "Tutorial 05 - Textured Cube", 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); 

// Initialize GLEW 
glewExperimental = true; // Needed for core profile 
if (glewInit() != GLEW_OK) { 
    fprintf(stderr, "Failed to initialize GLEW\n"); 
    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, 0.4f, 0.0f); 

// Enable depth test 
glEnable(GL_DEPTH_TEST); 
// Accept fragment if it closer to the camera than the former one 
glDepthFunc(GL_LESS); 

GLuint VertexArrayID; 
glGenVertexArrays(1, &VertexArrayID); 
glBindVertexArray(VertexArrayID); 

// Create and compile our GLSL program from the shaders 
GLuint programID = LoadShaders("TransformVertexShader.vertexshader", "TextureFragmentShader.fragmentshader"); 

// Get a handle for our "MVP" uniform 
GLuint MatrixID = glGetUniformLocation(programID, "MVP"); 

// Projection matrix : 45° Field of View, 4:3 ratio, display range : 0.1 unit <-> 100 units 
glm::mat4 Projection = glm::perspective(45.0f, 4.0f/3.0f, 0.1f, 100.0f); 
// Camera matrix 
glm::mat4 View  = glm::lookAt(
          glm::vec3(4,3,3), // Camera is at (4,3,3), in World Space 
          glm::vec3(0,0,0), // and looks at the origin 
          glm::vec3(0,1,0) // Head is up (set to 0,-1,0 to look upside-down) 
         ); 
// Model matrix : an identity matrix (model will be at the origin) 
glm::mat4 Model  = glm::mat4(1.0f); 
// Our ModelViewProjection : multiplication of our 3 matrices 
glm::mat4 MVP  = Projection * View * Model; // Remember, matrix multiplication is the other way around 

// Load the texture using any two methods 
//GLuint Texture = loadBMP_custom("uvtemplate.bmp"); 
GLuint Texture = loadDDS("uvtemplate.DDS"); 

// Get a handle for our "myTextureSampler" uniform 
GLuint TextureID = glGetUniformLocation(programID, "myTextureSampler"); 

// Our vertices. Tree consecutive floats give a 3D vertex; Three consecutive vertices give a triangle. 
// A cube has 6 faces with 2 triangles each, so this makes 6*2=12 triangles, and 12*3 vertices 
static const GLfloat g_vertex_buffer_data[] = { 
    -1.0f,-1.0f,-1.0f, 
    -1.0f,-1.0f, 1.0f, 
    -1.0f, 1.0f, 1.0f, 
    1.0f, 1.0f,-1.0f, 
    -1.0f,-1.0f,-1.0f, 
    -1.0f, 1.0f,-1.0f, 
    1.0f,-1.0f, 1.0f, 
    -1.0f,-1.0f,-1.0f, 
    1.0f,-1.0f,-1.0f, 
    1.0f, 1.0f,-1.0f, 
    1.0f,-1.0f,-1.0f, 
    -1.0f,-1.0f,-1.0f, 
    -1.0f,-1.0f,-1.0f, 
    -1.0f, 1.0f, 1.0f, 
    -1.0f, 1.0f,-1.0f, 
    1.0f,-1.0f, 1.0f, 
    -1.0f,-1.0f, 1.0f, 
    -1.0f,-1.0f,-1.0f, 
    -1.0f, 1.0f, 1.0f, 
    -1.0f,-1.0f, 1.0f, 
    1.0f,-1.0f, 1.0f, 
    1.0f, 1.0f, 1.0f, 
    1.0f,-1.0f,-1.0f, 
    1.0f, 1.0f,-1.0f, 
    1.0f,-1.0f,-1.0f, 
    1.0f, 1.0f, 1.0f, 
    1.0f,-1.0f, 1.0f, 
    1.0f, 1.0f, 1.0f, 
    1.0f, 1.0f,-1.0f, 
    -1.0f, 1.0f,-1.0f, 
    1.0f, 1.0f, 1.0f, 
    -1.0f, 1.0f,-1.0f, 
    -1.0f, 1.0f, 1.0f, 
    1.0f, 1.0f, 1.0f, 
    -1.0f, 1.0f, 1.0f, 
    1.0f,-1.0f, 1.0f 
}; 

// Two UV coordinatesfor each vertex. They were created withe Blender. 
static const GLfloat g_uv_buffer_data[] = { 
    0.000059f, 1.0f-0.000004f, 
    0.000103f, 1.0f-0.336048f, 
    0.335973f, 1.0f-0.335903f, 
    1.000023f, 1.0f-0.000013f, 
    0.667979f, 1.0f-0.335851f, 
    0.999958f, 1.0f-0.336064f, 
    0.667979f, 1.0f-0.335851f, 
    0.336024f, 1.0f-0.671877f, 
    0.667969f, 1.0f-0.671889f, 
    1.000023f, 1.0f-0.000013f, 
    0.668104f, 1.0f-0.000013f, 
    0.667979f, 1.0f-0.335851f, 
    0.000059f, 1.0f-0.000004f, 
    0.335973f, 1.0f-0.335903f, 
    0.336098f, 1.0f-0.000071f, 
    0.667979f, 1.0f-0.335851f, 
    0.335973f, 1.0f-0.335903f, 
    0.336024f, 1.0f-0.671877f, 
    1.000004f, 1.0f-0.671847f, 
    0.999958f, 1.0f-0.336064f, 
    0.667979f, 1.0f-0.335851f, 
    0.668104f, 1.0f-0.000013f, 
    0.335973f, 1.0f-0.335903f, 
    0.667979f, 1.0f-0.335851f, 
    0.335973f, 1.0f-0.335903f, 
    0.668104f, 1.0f-0.000013f, 
    0.336098f, 1.0f-0.000071f, 
    0.000103f, 1.0f-0.336048f, 
    0.000004f, 1.0f-0.671870f, 
    0.336024f, 1.0f-0.671877f, 
    0.000103f, 1.0f-0.336048f, 
    0.336024f, 1.0f-0.671877f, 
    0.335973f, 1.0f-0.335903f, 
    0.667969f, 1.0f-0.671889f, 
    1.000004f, 1.0f-0.671847f, 
    0.667979f, 1.0f-0.335851f 
}; 

GLuint vertexbuffer; 
glGenBuffers(1, &vertexbuffer); 
glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer); 
glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertex_buffer_data), g_vertex_buffer_data, GL_STATIC_DRAW); 

GLuint uvbuffer; 
glGenBuffers(1, &uvbuffer); 
glBindBuffer(GL_ARRAY_BUFFER, uvbuffer); 
glBufferData(GL_ARRAY_BUFFER, sizeof(g_uv_buffer_data), g_uv_buffer_data, GL_STATIC_DRAW); 

do{ 

    // Clear the screen 
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 

    // Use our shader 
    glUseProgram(programID); 

    // Send our transformation to the currently bound shader, 
    // in the "MVP" uniform 
    glUniformMatrix4fv(MatrixID, 1, GL_FALSE, &MVP[0][0]); 

    // Bind our texture in Texture Unit 0 
    glActiveTexture(GL_TEXTURE0); 
    glBindTexture(GL_TEXTURE_2D, Texture); 
    // Set our "myTextureSampler" sampler to user Texture Unit 0 
    glUniform1i(TextureID, 0); 

    // 1rst attribute buffer : vertices 
    glEnableVertexAttribArray(0); 
    glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer); 
    glVertexAttribPointer(
     0,     // attribute. 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 
    ); 

    // 2nd attribute buffer : UVs 
    glEnableVertexAttribArray(1); 
    glBindBuffer(GL_ARRAY_BUFFER, uvbuffer); 
    glVertexAttribPointer(
     1,        // attribute. No particular reason for 1, but must match the layout in the shader. 
     2,        // size : U+V => 2 
     GL_FLOAT,       // type 
     GL_FALSE,       // normalized? 
     0,        // stride 
     (void*)0       // array buffer offset 
    ); 

    // Draw the triangle ! 
    glDrawArrays(GL_TRIANGLES, 0, 12*3); // 12*3 indices starting at 0 -> 12 triangles 

    glDisableVertexAttribArray(0); 
    glDisableVertexAttribArray(1); 

    // Swap buffers 
    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); 

// Cleanup VBO and shader 
glDeleteBuffers(1, &vertexbuffer); 
glDeleteBuffers(1, &uvbuffer); 
glDeleteProgram(programID); 
glDeleteTextures(1, &TextureID); 
glDeleteVertexArrays(1, &VertexArrayID); 

// Close OpenGL window and terminate GLFW 
glfwTerminate(); 

return 0; 
} 

Jede Hilfe wird sehr geschätzt.

Answer 1

Ich denke, es ist, weil Sie sind nicht die y-Komponente des UV-Koord Invertieren (da DDS hat eine verschieden D3D-basierten Koordinatensystem im Vergleich zu OpenGL). Sie sollten es entweder im Fragment-Shader (so einfach wie 1.0f-uv.y) oder invertieren, bevor Sie das Bild komprimieren. Schauen Sie sich dieses Tutorial an (was übrigens super ist). Am Ende wird über die Invertierung der UVs gesprochen:

Die DXT-Komprimierung stammt aus der DirectX-Welt, in der die V-Textur-Koordinate im Vergleich zu OpenGL umgekehrt ist. Wenn Sie also komprimierte Texturen verwenden, müssen Sie (coord.u, 1.0-coord.v) verwenden, um das richtige Texel zu holen. Sie können dies tun, wann immer Sie wollen: in Ihrem Export-Skript, in dem Loader, in Ihrem Shader ...