我在屏幕上开发了一个简单的JOGL渲染立方体，遵循与iPhone上的OpenGL ES 2相同的程序。但这段代码在运行时不会显示任何内容。
有人可以帮助浏览并指出问题是什么吗？
这是我的代码
import com.jogamp.common.nio.Buffers;
import com.jogamp.opengl.*;
import com.jogamp.opengl.awt.GLCanvas;
import com.jogamp.opengl.util.FPSAnimator;
import org.joml.Matrix4f;
import org.joml.Vector3f;
import javax.swing.*;
import java.awt.*;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.ByteBuffer;
import java.nio.FloatBuffer;
import java.nio.IntBuffer;
import java.nio.ShortBuffer;
public class TestScene extends JFrame implements GLEventListener {
private static final float[] CUBE_POSITIONS = {
-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,
};
private static final short[] INDICIES = {
0, 1, 2, 0, 2, 3,//front
2, 1, 5, 6, 2, 5,//right
7, 6, 4, 6, 5, 4,//back
7, 4, 3, 3, 4, 0,//right
6, 7, 2, 7, 3, 2,//top
0, 4, 1, 1, 4, 5,//bottom
};
private GL4 gl;
private int program;
private Matrix4f projection = new Matrix4f();
private Matrix4f viewing = new Matrix4f();
private Matrix4f translation = new Matrix4f();
private int projectionIndex;
private int viewingMatrix;
private int transIndex;
private int positionIndex;
private int vbo;
private int vio;
public TestScene() throws HeadlessException {
super("Testing");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final GLCanvas canvas = new GLCanvas(new GLCapabilities(GLProfile.get(GLProfile.GL4)));
final FPSAnimator animator = new FPSAnimator(25);
animator.add(canvas);
animator.start();
canvas.addGLEventListener(this);
getContentPane().add(canvas);
setSize(800, 600);
setVisible(true);
}
@Override
public void init(final GLAutoDrawable drawable) {
gl = drawable.getGL().getGL4();
try {
//init program and shader
final int vertexShader = createShader("/Users/gang_liu/Develop/Java/ideaProject/KLM/JOGL_Studies_1/vertex.glsl", GL4.GL_VERTEX_SHADER);
final int fragmentShader = createShader("/Users/gang_liu/Develop/Java/ideaProject/KLM/JOGL_Studies_1/fragment.glsl", GL4.GL_VERTEX_SHADER);
program = gl.glCreateProgram();
gl.glAttachShader(program, vertexShader);
gl.glAttachShader(program, fragmentShader);
gl.glLinkProgram(program);
//generate vbo
final IntBuffer intBuffer = IntBuffer.allocate(1);
gl.glGenBuffers(1, intBuffer);
vbo = intBuffer.get();
gl.glBindBuffer(GL.GL_ARRAY_BUFFER, vbo);
gl.glBufferData(GL.GL_ARRAY_BUFFER, CUBE_POSITIONS.length * Buffers.SIZEOF_FLOAT, FloatBuffer.wrap(CUBE_POSITIONS), GL.GL_STATIC_DRAW);
intBuffer.flip();
//generate vio
gl.glGenBuffers(1, intBuffer);
vio = intBuffer.get();
gl.glBindBuffer(GL.GL_ELEMENT_ARRAY_BUFFER, vio);
gl.glBufferData(GL.GL_ELEMENT_ARRAY_BUFFER, INDICIES.length * Buffers.SIZEOF_SHORT, ShortBuffer.wrap(INDICIES), GL.GL_STATIC_DRAW);
//get program indexes
positionIndex = gl.glGetAttribLocation(program, "position");
projectionIndex = gl.glGetUniformLocation(program, "projection");
viewingMatrix = gl.glGetUniformLocation(program, "view");
transIndex = gl.glGetUniformLocation(program, "trans");
//init projection matrix;
final int width = getWidth();
final int height = getHeight();
projection.perspective(45.0f, (float)width/height, 1.0f, 100.0f);
viewing.lookAt(new Vector3f(0.0f, 0.0f, 10.0f), new Vector3f(0.0f, 0.0f, 0.0f), new Vector3f(0.0f, 1.0f, 0.0f));
} catch (final Exception ex){
ex.printStackTrace();
}
}
@Override
public void dispose(GLAutoDrawable drawable) {
}
@Override
public void display(final GLAutoDrawable drawable) {
gl.glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
gl.glEnable(GL4.GL_CULL_FACE);
gl.glEnable(GL4.GL_DEPTH_TEST);
gl.glClearDepth(1.0);
gl.glClear(GL4.GL_COLOR_BUFFER_BIT | GL4.GL_DEPTH_BUFFER_BIT);
gl.glUseProgram(program);
gl.glBindBuffer(GL4.GL_ARRAY_BUFFER, vbo);
gl.glEnableVertexAttribArray(positionIndex);
gl.glVertexAttribPointer(positionIndex, 3, gl.GL_FLOAT, false, Buffers.SIZEOF_FLOAT * 3, 0);
gl.glUniformMatrix4fv(projectionIndex, 1, false, FloatBuffer.wrap(projection.get(new float[16])));
gl.glUniformMatrix4fv(viewingMatrix, 1, false, FloatBuffer.wrap(viewing.get(new float[16])));
gl.glUniformMatrix4fv(transIndex, 1, false, FloatBuffer.wrap(translation.get(new float[16])));
gl.glBindBuffer(GL.GL_ELEMENT_ARRAY_BUFFER, vio);
gl.glDrawElements(gl.GL_TRIANGLES, INDICIES.length, gl.GL_UNSIGNED_SHORT, 0);
gl.glUseProgram(0);
}
@Override
public void reshape(GLAutoDrawable drawable, int x, int y, int width, int height) {
}
private int createShader(final String fileName, final int type) throws IOException {
final int shaderID = gl.glCreateShader(type);
final StringBuilder sb = new StringBuilder();
final BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(fileName)));
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line).append("\n");
}
gl.glShaderSource(shaderID, 1, new String[]{sb.toString()}, null, 0);
gl.glCompileShader(shaderID);
final IntBuffer intBuffer = IntBuffer.allocate(1);
gl.glGetShaderiv(shaderID, gl.GL_COMPILE_STATUS, intBuffer);
if (intBuffer.get() == gl.GL_FALSE) {
intBuffer.flip();
gl.glGetShaderiv(shaderID, gl.GL_INFO_LOG_LENGTH, intBuffer);
final int logLength = intBuffer.get();
final ByteBuffer byteBuffer = ByteBuffer.allocate(logLength);
gl.glGetShaderInfoLog(shaderID, logLength, null, byteBuffer);
System.out.println("Filed to compile " +
(type == GL4.GL_VERTEX_SHADER ? "vertex shader" : "fragment shader")
+ " shader :\n" + new String(byteBuffer.array()));
}
return shaderID;
}
public static void main(String[] args) {
new TestScene();
}
}
这里是着色器文件
顶点着色器
#version 400
uniform lowp mat4 trans;
uniform lowp mat4 view;
uniform lowp mat4 projection;
in lowp vec3 position;
out lowp vec3 out_color;
void main(){
gl_Position = projection * view * trans * vec4(position, 1.0);
out_color = position;
}
片段着色器
#version 400
in lowp vec3 out_color;
out vec4 fragColor;
void main(){
fragColor = vec4(out_color, 1.0);
}
我知道我应该计算CPU中的统一矩阵。再次，这对调试很有用。
除了这个问题，我还有另外一个问题。似乎一些与glGetAttribLocation和glGetUniformLocation这样的程序相关的opengl函数都有程序参数，这是否意味着我们不必在这些函数调用之前调用glUseProgram？这个假设是正确的吗？关于这个问题的任何意见都是受欢迎的。由于