纹理三角形，只渲染一种颜色

Question

在这个例子中，我尝试使用lwjgl在java中渲染一个简单的纹理三角形，但我简直搞不明白为什么渲染三角形会填充一种颜色。

颜色似乎是整个纹理的平均颜色或纹理的一个像素，如果我使图像为绿色，则呈现三角形绿色。

在此先感谢您的帮助。

import static org.lwjgl.glfw.GLFW.*; 
import static org.lwjgl.opengl.GL20.*; 
import static org.lwjgl.opengl.GL11.*; 
import static org.lwjgl.opengl.GL15.*; 
import static org.lwjgl.opengl.GL13.*; 
import static org.lwjgl.opengl.GL30.*; 
import static org.lwjgl.system.MemoryUtil.*; 

import java.io.FileInputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.nio.ByteBuffer; 
import java.nio.ByteOrder; 
import java.nio.FloatBuffer; 

import org.joml.Matrix4f; 
import org.lwjgl.glfw.GLFWErrorCallback; 
import org.lwjgl.glfw.GLFWKeyCallback; 
import org.lwjgl.glfw.GLFWWindowSizeCallback; 
import org.lwjgl.opengl.GL; 
import org.lwjgl.opengl.GL11; 

import de.matthiasmann.twl.utils.PNGDecoder; 
import de.matthiasmann.twl.utils.PNGDecoder.Format; 

public class TEST 
{ 
    public int WIDTH = 1000; 
    public int HEIGHT = 1000; 
    public float vertices[] = new float[] 
    { 
      //COORDINATES 
      0.0f, 0.8f, 0.0f,1.0f, 
      //COLOR NOT USED 
      0.0f,1.0f,0.0f,1.0f, 
      //TEXTURE COORDINATES 
      0.5f, 1.0f, 

      //COORDINATES 
      -0.8f,-0.8f, 0.0f,1.0f, 
      //COLOR NOT USED 
      1.0f,0.0f,0.0f,1.0f, 
      //TEXTURE COORDINATES 
      0.0f, 0.0f, 

      //COORDINATES 
      0.8f,-0.8f, 0.0f,1.0f, 
      //COLOR NOT USED 
      0.0f,0.0f,1.0f,1.0f, 
      //TEXTURE COORDINATES 
      1.0f, 0.0f 
    }; 

    public TEST() 
    { 

    } 


    public int start() throws IOException 
    { 
     glfwInit(); 
     glfwDefaultWindowHints(); 
     glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE); 
     glfwWindowHint(GLFW_RESIZABLE, GL11.GL_TRUE); 
     long window = glfwCreateWindow(WIDTH, HEIGHT, "HAHA", NULL, NULL); 

     glfwMakeContextCurrent(window); 
     glfwSwapInterval(1); 
     glfwShowWindow(window); 
     GL.createCapabilities(); 

     //CALLBACKS 
     GLFWKeyCallback keycallback = new GLFWKeyCallback() 
     { 

      @Override 
      public void invoke(long window, int key, int scancode, int action, int mods) 
      { 
       if(key==GLFW_KEY_ESCAPE&&action==GLFW_PRESS) 
       { 
        glfwSetWindowShouldClose(window, GLFW_TRUE); 
       } 
      } 
     }; 
     glfwSetKeyCallback(window,keycallback); 
     GLFWErrorCallback errorcallback = new GLFWErrorCallback() 
     { 

      @Override 
      public void invoke(int error, long description) 
      { 
       System.out.println("ERROR CODE: " + error + " ERROR DESCRITPION: "+description); 
      } 
     }; 
     glfwSetErrorCallback(errorcallback); 
     GLFWWindowSizeCallback windowsizecallback = new GLFWWindowSizeCallback() 
     { 
      @Override 
      public void invoke(long window, int width, int height) 
      { 
       glViewport(0, 0, width, height); 
       System.out.println(width+" "+height); 
      } 
     }; 
     glfwSetWindowSizeCallback(window, windowsizecallback); 



     ////////////////////////// 
     int VAO = glGenVertexArrays(); 
     glBindVertexArray(VAO); 


     ByteBuffer byteBuffer = ByteBuffer.allocateDirect(vertices.length * Float.BYTES); 
     byteBuffer.order(ByteOrder.nativeOrder()); 
     FloatBuffer floatBuffer = byteBuffer.asFloatBuffer(); 
     floatBuffer.clear(); 
     floatBuffer.put(vertices); 
     floatBuffer.flip(); 

     int VBO = glGenBuffers(); 
     glBindBuffer(GL_ARRAY_BUFFER, VBO); 
     glBufferData(GL_ARRAY_BUFFER, floatBuffer, GL_STATIC_DRAW); 

     glVertexAttribPointer(0, 4, GL_FLOAT, false, 40, 0); 
     glEnableVertexAttribArray(0); 
     glVertexAttribPointer(1, 4, GL_FLOAT, false, 40, 16); 
     glEnableVertexAttribArray(1); 
     glVertexAttribPointer(2, 2, GL_FLOAT, false, 40, 24); 
     glEnableVertexAttribArray(2); 

     glBindBuffer(GL_ARRAY_BUFFER, 0); 

     glBindVertexArray(0); 
     /////////////////////// 
     /////////////////////// 
     LoadFile loader = new LoadFile("res/shader.vs", "res/shader.frag"); 

     int vertexshader = glCreateShader(GL_VERTEX_SHADER); 
     int fragmentshader = glCreateShader(GL_FRAGMENT_SHADER); 

     glShaderSource(vertexshader, loader.readVertex()); 
     glShaderSource(fragmentshader, loader.readFragment()); 

     glCompileShader(vertexshader); 
     glCompileShader(fragmentshader); 

     System.out.println(glGetShaderInfoLog(vertexshader)); 
     System.out.println(glGetShaderInfoLog(fragmentshader)); 


     int program = glCreateProgram(); 

     glAttachShader(program, vertexshader); 
     glAttachShader(program, fragmentshader); 

     glLinkProgram(program); 

     glDeleteShader(vertexshader); 
     glDeleteShader(fragmentshader); 

     System.out.println(glGetProgramInfoLog(program)); 
     /////////////////////////// 

     int texture1 = glGenTextures(); 
     InputStream texture1inputstream = new FileInputStream("res/container2.png"); 
     PNGDecoder texture1decoder = new PNGDecoder(texture1inputstream); 
     ByteBuffer texture1buffer = ByteBuffer.allocateDirect(4*texture1decoder.getWidth()*texture1decoder.getHeight()).order(ByteOrder.nativeOrder()); 
     texture1decoder.decode(texture1buffer, texture1decoder.getWidth()*4, Format.RGBA); 
     texture1buffer.flip(); 

     glBindTexture(GL_TEXTURE_2D, texture1); 

     glTexImage2D 
     (
       GL_TEXTURE_2D, 
       0, 
       GL_RGBA, 
       texture1decoder.getWidth(), 
       texture1decoder.getHeight(), 
       0, 
       GL_RGBA, 
       GL_UNSIGNED_BYTE, 
       texture1buffer 
     ); 

     glGenerateMipmap(GL_TEXTURE_2D); 
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); 
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); 
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); 
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); 

     glBindTexture(GL_TEXTURE_2D, 0); 

     int textureloc = glGetUniformLocation(program, "texture"); 

     //MAKE UNIFORM SETTER 
     UniformSetter uniformsetter = new UniformSetter(program, "model", "projection","view"); 
     ///////////////////// 

     glEnable(GL_DEPTH_TEST); 

     boolean running=true; 

     while(running&&glfwWindowShouldClose(window)==GLFW_FALSE) 
     { 
      glfwPollEvents(); 
      glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT); 
      glClearColor(1.0f, 0.0f, 0.0f, 1.0f); 

      glUseProgram(program); 

      glBindVertexArray(VAO); 
      /////////////////////// 

      for(int a = 0;a<4;a++) 
      { 
       //MAKE MATRIX MODEL 
       Matrix4f model = new Matrix4f(); 

       model.translate(0.0f,0.0f,0.0f); 
       float xang = 0f; 
       float yang = 0f; 
       float zang = 0f; 
       model.rotate((float) Math.toRadians(xang), 1.0f, 0.0f, 0.0f); 
       model.rotate((float) Math.toRadians(yang), 0.0f, 1.0f, 0.0f); 
       model.rotate((float) Math.toRadians(zang), 0.0f, 0.0f, 1.0f); 
       model.scale(0.5f); 

       uniformsetter.setModel(model); 
       //////////////////// 

       //MAKE MATRIX VIEW 
       Matrix4f view = new Matrix4f(); 

       view.lookAt(0.0f, 0.0f, 1.0f, 
          0.0f, 0.0f, 0.0f, 
          0.0f, 1.0f, 0.0f); 

       uniformsetter.setView(view); 
       ////////////////// 

       //MAKE MATRIX PROJECTION 
       Matrix4f projection = new Matrix4f(); 

       projection.ortho(-1.0f, 1.0f, -1.0f, 1.0f,1.0f,-1.0f); 

       uniformsetter.setProjection(projection); 
       ///////////////////////// 

       //ACTIVATE AND BIND TEXTURE 
       glActiveTexture(GL_TEXTURE0); 
       glBindTexture(GL_TEXTURE_2D, texture1); 
       glUniform1i(textureloc, 0); 

       /////////////////////////// 

       glDrawArrays(GL_TRIANGLES, 0, 3); 

       glBindTexture(GL_TEXTURE_2D, 0); 
      } 

      /////////////////////// 
      glBindVertexArray(0); 

      glUseProgram(0); 

      glfwSwapInterval(1); 
      glfwSwapBuffers(window); 
     } 

     System.out.println(glGetError()); 
     glfwTerminate(); 

     return 0; 
    } 
} 

顶点着色器：

#version 440 
layout (location = 0) in vec4 position; 
//NOT USED layout (location = 1) in vec4 colorin; 
layout (location = 2) in vec2 texturecoordiantesin; 

//NOT USED out vec4 colorout; 
out vec2 texturecoordinatesout; 

uniform mat4 model; 
uniform mat4 view; 
uniform mat4 projection; 

void main() 
{ 
    gl_Position = projection*view*model*position; 
    //NOT USED colorout=colorin; 
} 

片段着色器：

#version 440 
out vec4 color; 

//NOT USED in vec4 colorout; 
in vec2 texturecoordinatesout; 
uniform sampler2D texture; 

void main() 
{ 
    color = texture2D(texture,texturecoordinatesout); 
} 

Answer 1

你缺少的顶点着色器的texturecoordinatesin的传播。在顶点着色器的任意位置添加这个：

texturecoordinatesout = texturecoordinatesin; 

另外，当你设置顶点数组指针时你犯了一个错误。 glVertexAttribPointer为属性2的最后一个参数应为32 4个浮点用于位置偏移和4周的float颜色偏移是总共8浮起的偏移，或32个字节：

glVertexAttribPointer(0, 4, GL_FLOAT, false, 40, 0); 
    glEnableVertexAttribArray(0); 
    glVertexAttribPointer(1, 4, GL_FLOAT, false, 40, 16); 
    glEnableVertexAttribArray(1); 
    glVertexAttribPointer(2, 2, GL_FLOAT, false, 40, 32); 
    glEnableVertexAttribArray(2);