C++ 如何调试openGL代码?

C++ 如何调试openGL代码?,c++,c,opengl,visual-c++,opengl-3,C++,C,Opengl,Visual C++,Opengl 3,我对openGL调试有问题。我发现很多时候,OpenGL会向你们展示它失败的原因是并没有画任何东西。每次代码看起来都很好,但它并没有在GL窗口上绘制任何东西 < >考虑下面的代码。我编写它来绘制立方体,但它没有画任何东西,我找不到原因。 ======================================================== // cube_vertex_array.cpp : Defines the entry point for the console applica

我对openGL调试有问题。我发现很多时候,OpenGL会向你们展示它失败的原因是并没有画任何东西。每次代码看起来都很好,但它并没有在GL窗口上绘制任何东西

< >考虑下面的代码。我编写它来绘制立方体,但它没有画任何东西,我找不到原因。

========================================================

// cube_vertex_array.cpp : Defines the entry point for the console application.

#include "stdafx.h"
#include <glut.h>

static GLfloat vertex[]=
                        {
                            100.0,100.0,0.0,
                            400.0,100.0,0.0,
                            400.0,400.0,0.0,
                            100.0,400.0,0.0,
                            100.0,100.0,-300.0,
                            400.0,100.0,-300.0,
                            400.0,400.0,-300.0,
                            100.0,400.0,-300.0
                    };

static GLfloat color[]=
                        {
                            1.0,0.0,0.0,
                            0.0,1.0,0.0,
                            0.0,0.0,1.0,
                            1.0,1.0,0.0,
                            1.0,0.0,1.0,
                            0.0,1.0,1.0
                        };


static GLubyte frontIndices[] = {0,1,2,3};
static GLubyte leftIndices[] = {1,5,6,2};
static GLubyte backIndices[] = {4,7,6,5};
static GLubyte rightIndices[] = {0,3,7,4};
static GLubyte topIndices[] = {3,2,6,7};
static GLubyte bottomIndices[] = {0,4,5,1};

void init(void)
{
    glClearColor(0.0,0.0,0.0,0.0);                              //Set default background color to black.
    glClearDepth(2.0);                                      //Set the depth level for clearing depth buffer.
    glShadeModel(GL_FLAT);                                  //Set the     shading model to FLAT
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);     //Clear the color and depth buffer.
}

void Display(void)
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);     //Clear the color and depth buffer.

glColor3f(1.0,0.0,0.0);

//glBegin(GL_LINE_STRIP);
//  glVertex3f(0.0,0.0,0.0);
//  glVertex3f(200.0,100.0,0.0);
//glEnd();  

glEnableClientState(GL_VERTEX_ARRAY);                   //Enable vertex array.
glEnableClientState(GL_COLOR_ARRAY);                    //Enable vertex array color.

glColorPointer(3,GL_FLOAT,0,color);                     //Specify the array for colors.
glVertexPointer(3,GL_FLOAT,0,vertex);                   //Specify the array for vertex.

glDrawElements(GL_QUADS,4,GL_UNSIGNED_BYTE,frontIndices);      //Draw front face.
glDrawElements(GL_QUADS,4,GL_UNSIGNED_BYTE,leftIndices);       //Draw left face.
glDrawElements(GL_QUADS,4,GL_UNSIGNED_BYTE,backIndices);       //Draw back face.
glDrawElements(GL_QUADS,4,GL_UNSIGNED_BYTE,rightIndices);      //Draw right face.
glDrawElements(GL_QUADS,4,GL_UNSIGNED_BYTE,topIndices);        //Draw top face.
glDrawElements(GL_QUADS,4,GL_UNSIGNED_BYTE,bottomIndices);     //Draw bottom face.

glutSwapBuffers();               //Swap the buffers.
}

void Reshape(int w,int h)
{
    glViewport(0.0,(GLsizei)w,0.0,(GLsizei)h);           //Set the viewport according to new window size.
    glMatrixMode(GL_PROJECTION);                         //Set matrix mode to projection.
    glLoadIdentity();                                    //Replace the top matrix in the stack to the identity matrix.
    gluOrtho2D(0.0,(GLdouble)w,0.0,(GLdouble)h);         //Set the orthographic projection.
    glMatrixMode(GL_MODELVIEW);                          //Set matrix mode to modelview.
}

int main(int argc, char **argv)
{
    glutInit(&argc,argv);                             //Initialize the glut.
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);      //Set display mode and also enable double buffering.
    glutInitWindowSize(500,500);                      //Set the initial window size.
    glutCreateWindow("Cube");                         //Create the window and also assign name to it.
    init();                                           //Initialize the app.
    glutDisplayFunc(Display);                         //Register the Display function.
    glutReshapeFunc(Reshape);                         //Register the Reshape function.
    glutMainLoop();                                   //Start the main loop.
    return 0;
}
//cube\u vertex\u array.cpp:定义控制台应用程序的入口点。
#包括“stdafx.h”
#包括
静态GLfloat顶点[]=
{
100.0,100.0,0.0,
400.0,100.0,0.0,
400.0,400.0,0.0,
100.0,400.0,0.0,
100.0,100.0,-300.0,
400.0,100.0,-300.0,
400.0,400.0,-300.0,
100.0,400.0,-300.0
};
静态GLfloat颜色[]=
{
1.0,0.0,0.0,
0.0,1.0,0.0,
0.0,0.0,1.0,
1.0,1.0,0.0,
1.0,0.0,1.0,
0.0,1.0,1.0
};
静态索引[]={0,1,2,3};
静态索引[]={1,5,6,2};
静态GLubyte反向索引[]={4,7,6,5};
静态GLubyte RightIndex[]={0,3,7,4};
静态索引[]={3,2,6,7};
静态索引[]={0,4,5,1};
void init(void)
{
glClearColor(0.0,0.0,0.0,0.0);//将默认背景色设置为黑色。
glClearDepth(2.0);//设置清除深度缓冲区的深度级别。
glShadeModel(GL_平面);//将着色模型设置为平面
glClear(GL_颜色_缓冲区| GL_深度_缓冲区|位);//清除颜色和深度缓冲区。
}
作废显示(作废)
{
glClear(GL_颜色_缓冲区| GL_深度_缓冲区|位);//清除颜色和深度缓冲区。
GL3F(1.0,0.0,0.0);
//glBegin(GL_线_带);
//glVertex3f(0.0,0.0,0.0);
//glVertex3f(200.0100.0,0.0);
//格伦德();
glEnableClientState(GL_顶点数组);//启用顶点数组。
glEnableClientState(GL_颜色_数组);//启用顶点数组颜色。
glColorPointer(3,GL_FLOAT,0,color);//指定颜色的数组。
glVertexPointer(3,GL_FLOAT,0,顶点);//指定顶点的数组。
gldrawerelements(GL_四元组,4,GL_无符号字节,frontindex);//绘制正面。
GLD元素(GL_四元组,4,GL_无符号字节,左索引);//绘制左面。
GLD元素(GL_四元组,4,GL_无符号字节,后向索引);//后向绘制面。
GLD元素(GL_四元组,4,GL_无符号字节,右索引);//绘制右面。
gldrawerelements(GL_四边形,4,GL_无符号字节,topIndex);//绘制顶面。
GLD元素(GL_四元组,4,GL_无符号字节,底部索引);//绘制底面。
glutSwapBuffers();//交换缓冲区。
}
空洞重塑(整数w,整数h)
{
glViewport(0.0,(GLsizei)w,0.0,(GLsizei)h);//根据新窗口大小设置视口。
glMatrixMode(GL_投影);//将矩阵模式设置为投影。
glLoadIdentity();//将堆栈中的顶部矩阵替换为标识矩阵。
gluOrtho2D(0.0,(GLdouble)w,0.0,(GLdouble)h);//设置正交投影。
glMatrixMode(GL_MODELVIEW);//将矩阵模式设置为MODELVIEW。
}
int main(int argc,字符**argv)
{
glutInit(&argc,argv);//初始化glut。
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);//设置显示模式并启用双缓冲。
GLUTINITWindowsSize(500500);//设置初始窗口大小。
glutCreateWindow(“多维数据集”);//创建窗口并为其指定名称。
init();//初始化应用程序。
glutDisplayFunc(显示);//注册显示函数。
GLUTREFORMATEFUNC(REFORMATE);//注册REFORMATE函数。
glutMainLoop();//启动主循环。
返回0;
}

使用glTrace/glIntercept(查看OpenGL调用跟踪)、gDebugger(可视化纹理、着色器、OGL状态等)

使用glTrace/glIntercept(查看OpenGL调用跟踪)、gDebugger(可视化纹理、着色器、OGL状态等)等工具。

您已将GL_UNSIGNED_字节作为gldrawerelements中的类型参数()。这将导致openGL将插入的索引数组解释为每个索引一个字节。您应该在此处使用GL_UNSIGNED_INT

以下是基于您提供的代码的工作代码(尽管我已将其移植到java):

导入java.nio.ByteBuffer;
导入org.lwjgl.BufferUtils;
导入org.lwjgl.LWJGLException;
导入org.lwjgl.opengl.Display;
导入org.lwjgl.opengl.DisplayMode;
导入静态org.lwjgl.opengl.GL11.*;
公开课考试{
公共静态void main(字符串[]args){
试一试{
Display.create();
Display.setDisplayMode(新的显示模式(500500));
Display.setresizeable(true);
//与指定的数组相同。
float[]顶点=新的float[]{100.0f,100.0f,0.0f,
400.0华氏度,100.0华氏度,0.0华氏度,
400.0f,400.0f,0.0f,
100.0f、400.0f、0.0f、,
100.0f,100.0f,-300.0f,
400.0华氏度,100.0华氏度,-300.0华氏度,
400.0f,400.0f,-300.0f,
100.0f,400.0f,-300.0f};
float[]color=新的float[]{1,0,0,
0,1,0,
0,0,1,
1,1,0,
1,0,1,
0,1,1};
import java.nio.ByteBuffer;

import org.lwjgl.BufferUtils;
import org.lwjgl.LWJGLException;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;

import static org.lwjgl.opengl.GL11.*;

public class GLTest {
    public static void main(String[] args) {
        try {
            Display.create();
            Display.setDisplayMode(new DisplayMode(500, 500));
            Display.setResizable(true);

            //the same arrays as the ones you specified.

            float[] vertices = new float[]{100.0f,100.0f,0.0f,
                    400.0f,100.0f,0.0f,
                    400.0f,400.0f,0.0f,
                    100.0f,400.0f,0.0f,
                    100.0f,100.0f,-300.0f,
                    400.0f,100.0f,-300.0f,
                    400.0f,400.0f,-300.0f,
                    100.0f,400.0f,-300.0f};

            float[] color = new float[]{1,0,0,
                    0,1,0,
                    0,0,1,
                    1,1,0,
                    1,0,1,
                    0,1,1};

            int[] frontIndices = new int[]{0, 1, 2, 3};


            //JWJGL bookkeeping.. 
            ByteBuffer vertexBuffer = BufferUtils.createByteBuffer(vertices.length * 4);
            ByteBuffer colourBuffer = BufferUtils.createByteBuffer(color.length * 4);

            for(int i = 0; i < vertices.length; i++) {
                vertexBuffer.putFloat(vertices[i]);
            }
            vertexBuffer.rewind();

            for(int i = 0; i < color.length; i++) {
                colourBuffer.putFloat(color[i]);
            }
            colourBuffer.rewind();


            ByteBuffer indexBuffer = BufferUtils.createByteBuffer(4 * frontIndices.length);
            for(int i = 0; i < frontIndices.length; i++) {
                indexBuffer.putInt(frontIndices[i]);
            }
            indexBuffer.rewind();

            //back you your code

            glClearColor(1,1,1,1);
            glShadeModel(GL_SMOOTH);

            while(!Display.isCloseRequested()) {
                glViewport(0, 0, Display.getWidth(), Display.getHeight()); 
                glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
                glMatrixMode(GL_PROJECTION);
                glLoadIdentity();
                glOrtho(0,Display.getWidth(), 0, Display.getHeight(), -1, 1);     
                glMatrixMode(GL_MODELVIEW);
                glLoadIdentity();

                glEnableClientState(GL_VERTEX_ARRAY);         
                glEnableClientState(GL_COLOR_ARRAY);         

                glColorPointer(3, GL_FLOAT, 0, colourBuffer);       
                glVertexPointer(3, GL_FLOAT, 0, vertexBuffer);          

                glDrawElements(GL_QUADS, 4, GL_UNSIGNED_INT, indexBuffer);    
                Display.update();
                Display.sync(60);
            }
        } catch (LWJGLException e) {
            e.printStackTrace();
        }
    }
}