qt opengl 使用不同的颜色绘制线框三角形

先看效果：

#pragma once

#include <QOpenGLWidget>
#include <QOpenGLFunctions_3_3_Core>
#include <QOpenGLShader>
#include <QOpenGLShaderProgram>

class MyOpenGLWgt : public QOpenGLWidget,public QOpenGLFunctions_3_3_Core {
    
	Q_OBJECT

public:
	MyOpenGLWgt(QWidget *parent = Q_NULLPTR);
	~MyOpenGLWgt();

private:
	void initializeGL()override;
	void resizeGL(int w, int h)override;
	void paintGL()override;

private:
	GLuint VBOs[2], VAOs[2];
	QOpenGLShaderProgram _shaderProgram;//着色器程序，管理系统所有的着色器
	QOpenGLShaderProgram _shaderProgram2;//着色器程序，管理系统所有的着色器
};

#include "MyOpenGLWgt.h"


MyOpenGLWgt::MyOpenGLWgt(QWidget *parent) :QOpenGLWidget(parent) {
    
}

MyOpenGLWgt::~MyOpenGLWgt() {
    
	glDeleteBuffers(2, VBOs);
	glDeleteVertexArrays(2, VAOs);
}

void MyOpenGLWgt::initializeGL() {
    
	initializeOpenGLFunctions();

	GLfloat firstTriangle[] = {
    
		-0.9f, -0.5f, 0.0f,
		-0.0f, -0.5f, 0.0f,
		-0.45f, 0.5f, 0.0f
	};

	GLfloat secondTriangle[] = {
    
		0.0f, -0.5f, 0.0f,
		0.9f, -0.5f, 0.0f,
		0.45f, 0.5f, 0.0f
	};

	//一次创建多个对象
	glGenVertexArrays(2, VAOs);
	glGenBuffers(2, VBOs);

	//第一个三角形
	glBindVertexArray(VAOs[0]);
	glBindBuffer(GL_ARRAY_BUFFER, VBOs[0]);

	glBufferData(GL_ARRAY_BUFFER, sizeof(firstTriangle), firstTriangle, GL_STATIC_DRAW);
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(GLfloat), (void*)0);
	glEnableVertexAttribArray(0);//VAOs[0]的第一个属性

	glBindVertexArray(0);
	glBindBuffer(VBOs[0], 0);

	//第二个三角形
	glBindVertexArray(VAOs[1]);
	glBindBuffer(GL_ARRAY_BUFFER, VBOs[1]);

	glBufferData(GL_ARRAY_BUFFER, sizeof(secondTriangle), secondTriangle, GL_STATIC_DRAW);
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(GLfloat), (void*)0);
	glEnableVertexAttribArray(0);//VAOs[1]的第一个属性

	glBindVertexArray(0);
	glBindBuffer(VBOs[1], 0);

	//绑定Shader
	QOpenGLShader vertexShager(QOpenGLShader::Vertex);//顶点着色器
	vertexShager.compileSourceFile("E:/Projects/QtGuiTest/OPenGLApp/TwoTriangle/FirstTriangle.vert");
	QOpenGLShader fragmentShager(QOpenGLShader::Fragment);//片段着色器
	fragmentShager.compileSourceFile("E:/Projects/QtGuiTest/OPenGLApp/TwoTriangle/FirstTriangle.frag");
	_shaderProgram.addShader(&vertexShager);
	_shaderProgram.addShader(&fragmentShager);

	_shaderProgram.link();

	//第二个shader程序
	QOpenGLShader vertexShager2(QOpenGLShader::Vertex);//顶点着色器
	vertexShager2.compileSourceFile("E:/Projects/QtGuiTest/OPenGLApp/TwoTriangle/FirstTriangle.vert");
	QOpenGLShader fragmentShager2(QOpenGLShader::Fragment);//片段着色器
	fragmentShager2.compileSourceFile("E:/Projects/QtGuiTest/OPenGLApp/TwoTriangle/SecondTriangle.frag");
	_shaderProgram2.addShader(&vertexShager2);
	_shaderProgram2.addShader(&fragmentShager2);

	_shaderProgram2.link();

	//设置成线框模式
	glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
}

void MyOpenGLWgt::resizeGL(int w, int h) {
    

}

void MyOpenGLWgt::paintGL() {
    
	glClearColor(0.4f, 0.4f, 0.4f, 1.0f);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	_shaderProgram.bind();
	glBindVertexArray(VAOs[0]);
	glDrawArrays(GL_TRIANGLES, 0, 3);

	_shaderProgram2.bind();
	glBindVertexArray(VAOs[1]);
	glDrawArrays(GL_TRIANGLES, 0, 3);

	update();
}

顶点着色器：

#version 330 core
layout (location = 0) in vec3 aPos;
void main(){
    
	gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);
}

第一个片段着色器：

#version 330 core
out vec4 fragColor;

void main(){
    
	fragColor = vec4(0.0f, 0.0f, 1.0f, 1.0f);
}

第二个片段着色器：

#version 330 core
out vec4 fragColor;

void main(){
    
	fragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);
}

aaa