OpenGL 超级宝典学习，制作 圆柱，球体，花托，圆盘等多边体

#include <GLTools.h>
#include <GLMatrixStack.h>
#include <GLFrame.h>
#include <GLFrustum.h>
#include <GLBatch.h>
#include <GLGeometryTransform.h>
#include <math.h>
#ifdef __APPLE__
#include <glut/glut.h>
#else
#define FREEGLUT_STATIC
#include <gl/glut.h>
#endif




GLShaderManager shaderManager; //着色管理器
GLMatrixStack   modelViewMatrix;
GLMatrixStack   projectionMatrix;
GLFrame         cameraFrame;
GLFrame         objectFrame;
GLFrustum       viewFrustum;


GLTriangleBatch sphereBatch;
GLTriangleBatch torusBatch;
GLTriangleBatch cylinderBatch;
GLTriangleBatch coneBatch;
GLTriangleBatch diskBatch;


GLGeometryTransform transformPipeline;
M3DMatrix44f    shadowMatrix;


GLfloat vGreen[] = { 0.0f, 1.0f, 0.0f, 1.0f };
GLfloat vBlack[] = { 0.0f, 0.0f, 0.0f, 1.0f };


int nStep = 0;


void SetupRC()
{
glClearColor(0.7f, 0.7f, 0.7f, 1.0f);
shaderManager.InitializeStockShaders(); 初始化
glEnable(GL_DEPTH_TEST); // 开启深度测试
transformPipeline.SetMatrixStacks(modelViewMatrix, projectionMatrix);
cameraFrame.MoveForward(-15.0f);
gltMakeSphere(sphereBatch, 3.0, 10, 20);// 球体
gltMakeTorus(torusBatch, 3.0f, 0.75f, 15, 15); // 花托
gltMakeCylinder(cylinderBatch, 2.0f, 2.0f, 3.0f, 13, 2);//圆柱
gltMakeCylinder(coneBatch, 2.0f, 0.0f, 3.0f, 13, 2);
gltMakeDisk(diskBatch, 1.5f, 3.0f, 13, 3);//圆盘
}


void DrawWireFramedBatch(GLTriangleBatch* pBatch)
{
shaderManager.UseStockShader(GLT_SHADER_FLAT, transformPipeline.GetModelViewProjectionMatrix(), vGreen);
pBatch->Draw();


// Draw black outline
glPolygonOffset(-1.0f, -1.0f);
glEnable(GL_LINE_SMOOTH);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glEnable(GL_POLYGON_OFFSET_LINE);
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
glLineWidth(2.5f);
shaderManager.UseStockShader(GLT_SHADER_FLAT, transformPipeline.GetModelViewProjectionMatrix(), vBlack);
pBatch->Draw();


// Restore polygon mode and depht testing
glPolygonMode(GL_FRONT, GL_FILL);
glDisable(GL_POLYGON_OFFSET_LINE);
glLineWidth(1.0f);
glDisable(GL_BLEND);
glDisable(GL_LINE_SMOOTH);
}


void RenderScene(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
modelViewMatrix.PushMatrix();
M3DMatrix44f mCamara;
cameraFrame.GetCameraMatrix(mCamara);
modelViewMatrix.MultMatrix(mCamara);
M3DMatrix44f mObjectFrame;
objectFrame.GetMatrix(mObjectFrame);
modelViewMatrix.MultMatrix(mObjectFrame);
shaderManager.UseStockShader(GLT_SHADER_FLAT, transformPipeline.GetModelViewProjectionMatrix(), vBlack);
switch (nStep) {
case 0:
DrawWireFramedBatch(&sphereBatch);
break;
case 1:
DrawWireFramedBatch(&torusBatch);
break;
case 2:
DrawWireFramedBatch(&cylinderBatch);
break;
case 3:
DrawWireFramedBatch(&coneBatch);
break;
case 4:
DrawWireFramedBatch(&diskBatch);
break;
}
modelViewMatrix.PopMatrix();


// Flush drawing commands
glutSwapBuffers();
}


// Respond to arrow keys by moving the camera frame of reference
void SpecialKeys(int key, int x, int y)
{
if (key == GLUT_KEY_UP)
objectFrame.RotateWorld(m3dDegToRad(-5.0f), 1.0f, 0.0f, 0.0f);


if (key == GLUT_KEY_DOWN)
objectFrame.RotateWorld(m3dDegToRad(5.0f), 1.0f, 0.0f, 0.0f);


if (key == GLUT_KEY_LEFT)
objectFrame.RotateWorld(m3dDegToRad(-5.0f), 0.0f, 1.0f, 0.0f);


if (key == GLUT_KEY_RIGHT)
objectFrame.RotateWorld(m3dDegToRad(5.0f), 0.0f, 1.0f, 0.0f);


glutPostRedisplay();
}


void KeyPressFunc(unsigned char key, int x, int y)
{
if (key == 32)
{
nStep++;
if (nStep > 4)
nStep = 0;
}
switch (nStep)
{
case 0:
glutSetWindowTitle("Sphere");
break;
case 1:
glutSetWindowTitle("Torus");
break;
case 2:
glutSetWindowTitle("Cylinder");
break;
case 3:
glutSetWindowTitle("Cone");
break;
case 4:
glutSetWindowTitle("Disk");
break;
}


glutPostRedisplay();
}


void ChangeSize(int w, int h)
{
glViewport(0, 0, w, h);
viewFrustum.SetPerspective(35.0f, float(w) / float(h), 1.0f, 500.0f);
projectionMatrix.LoadMatrix(viewFrustum.GetProjectionMatrix());
modelViewMatrix.LoadIdentity();
}
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("Sphere");
glutReshapeFunc(ChangeSize);
glutKeyboardFunc(KeyPressFunc);
glutSpecialFunc(SpecialKeys);
glutDisplayFunc(RenderScene);


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




SetupRC();


glutMainLoop();
return 0;
}