OpenGL 第一个函数 三角形绘制

VS2017测试，可运行

// Triangle.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
//

//#include "pch.h"
#include 
#include
// Triangle.cpp
// Our first OpenGL program that will just draw a triangle on the screen.

#include             // OpenGL toolkit
#include     // Shader Manager Class

#ifdef __APPLE__
#include           // OS X version of GLUT
#else
#define FREEGLUT_STATIC
#include             // Windows FreeGlut equivalent
#endif

GLBatch	triangleBatch;
GLShaderManager	shaderManager;

//#pragma comment(lib,"glew32.lib")

#pragma comment(lib,"gltools.lib")


///////////////////////////////////////////////////////////////////////////////
// Window has changed size, or has just been created. In either case, we need
// to use the window dimensions to set the viewport and the projection matrix.
void ChangeSize(int w, int h)
{
	glViewport(0, 0, w, h);
}


///////////////////////////////////////////////////////////////////////////////
// This function does any needed initialization on the rendering context. 
// This is the first opportunity to do any OpenGL related tasks.
void SetupRC()
{
	// Blue background
	glClearColor(0.0f, 0.0f, 1.0f, 1.0f);

	shaderManager.InitializeStockShaders();

	// Load up a triangle
	GLfloat vVerts[] = { -0.5f, 0.0f, 0.0f,
						  0.5f, 0.0f, 0.0f,
						  0.0f, 0.5f, 0.0f };

	triangleBatch.Begin(GL_TRIANGLES, 3);
	triangleBatch.CopyVertexData3f(vVerts);
	triangleBatch.End();
}



///////////////////////////////////////////////////////////////////////////////
// Called to draw scene
void RenderScene(void)
{
	// Clear the window with current clearing color
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

	GLfloat vRed[] = { 1.0f, 0.0f, 0.0f, 1.0f };
	shaderManager.UseStockShader(GLT_SHADER_IDENTITY, vRed);
	triangleBatch.Draw();

	// Perform the buffer swap to display back buffer
	glutSwapBuffers();
}


///////////////////////////////////////////////////////////////////////////////
// Main entry point for GLUT based programs
int main(int argc, char* argv[])
{
	gltSetWorkingDirectory(argv[0]);

	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH | GLUT_STENCIL);
	glutInitWindowSize(800, 600);
	glutCreateWindow("Triangle");
	glutReshapeFunc(ChangeSize);
	glutDisplayFunc(RenderScene);

	GLenum err = glewInit();
	if (GLEW_OK != err) {
		fprintf(stderr, "GLEW Error: %s\n", glewGetErrorString(err));
		return 1;
	}

	SetupRC();

	glutMainLoop();
}

注解：

//显示模式
glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGBA|GLUT_DEPTH|GLUT_STENCIL);
 //GLUT_DOUBLE 双缓冲窗口，指绘图命令实际上是在离屏缓冲区执行的，然后迅速转换成窗口视图，这种方式经常生成动画效果
 //GLUT_RGBA 颜色模式
 // GLUT_DEPTH 将一个深度缓冲区分配为显示的一部分
 //GLUT_STENCIL 模板缓冲区