QT OpenGL绘制三维图形（立方体、圆柱体、圆锥、球体、圆环等等）
本文使用QGLWidget来绘制各种三维基本图形，包括立方体、圆柱体、圆锥、球体、圆环等等，涉及包括基本绘制以及上色、纹理、旋转等操作。
使用的软件版本：QT5.12 + QT Creater4.8.0
GLWidget.h
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#ifndef GLWIDGET_H
#define GLWIDGET_H #include <QGLWidget> class GLWidget : public QGLWidget { Q_OBJECT public: GLWidget(QWidget *parent = 0); ~GLWidget(); protected: // 设置渲染环境 void initializeGL(); // 绘制窗口 void paintGL(); // 响应窗口的大小变化 void resizeGL(int width, int height); private: // 场景渲染 void renderScene(); // 场景渲染-基本图形 void renderBasicShape(); // 场景渲染-立方体纹理 void renderTextureCube(); // 场景渲染-圆柱体纹理 void renderTextureCylinder(); // 绘制立方体 void drawCube(); // 绘制圆形 void drawCircle(); // 绘制圆柱体 void drawCylinder(); // 绘制圆锥体 void drawCone(); // 绘制四面体 void drawTetrahedron(); // 绘制球体 void drawSphere(GLfloat xx = 0.0, GLfloat yy = 0.0, GLfloat zz = 0.0, GLfloat radius = 1.0, GLfloat M = 100.0, GLfloat N = 100.0); // 绘制圆环 void DrawTorus(double Radius = 1, double TubeRadius = 0.2, int Sides = 20, int Rings = 30); // 加载纹理 void loadGLTextures(); private: // 旋转角度 GLfloat xRot; GLfloat yRot; GLfloat zRot; // 存储纹理 GLuint texture[2]; }; #endif // GLWIDGET_H |
GLWidget.cpp
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#include "GLWidget.h"
#include <qmath.h> #define PI 3.14 #define ROT_DELTA 0.5f void qgluPerspective(GLdouble fovy, GLdouble aspect, GLdouble zNear, GLdouble zFar) { const GLdouble ymax = zNear * tan(qDegreesToRadians(fovy) / 2.0); const GLdouble ymin = -ymax; const GLdouble xmin = ymin * aspect; const GLdouble xmax = ymax * aspect; glFrustum(xmin, xmax, ymin, ymax, zNear, zFar); } GLWidget::GLWidget(QWidget *parent) : QGLWidget(parent) , xRot(0.0f) , yRot(0.0f) , zRot(0.0f) { // 设置画面的双缓冲和深度缓存 setFormat(QGLFormat(QGL::DoubleBuffer | QGL::DepthBuffer)); } GLWidget::~GLWidget() { } void GLWidget::initializeGL() { // 启用阴影平滑 glShadeModel(GL_SMOOTH); // 白色背景 glClearColor(1.0, 1.0, 1.0, 1.0); // 设置深度缓存 glClearDepth(1.0); // 启用深度测试 glEnable(GL_DEPTH_TEST); // 所作深度测试的类型 glDepthFunc(GL_LEQUAL); // 告诉系统对透视进行修正 glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); // 启用2D纹理映射 glEnable(GL_TEXTURE_2D); // 加载纹理 loadGLTextures(); } void GLWidget::paintGL() { renderScene(); update(); } void GLWidget::resizeGL(int width, int height) { // 防止窗口大小变为0 if ( height == 0 ) { height = 1; } // 重置当前的视口 glViewport(0, 0, (GLint)width, (GLint)height); // 选择投影矩阵 glMatrixMode(GL_PROJECTION); // 重置投影矩阵 glLoadIdentity(); // 设置视口的大小 qgluPerspective(45.0, (GLdouble)width / (GLdouble)height, 0.1, 100.0); // 选择模型观察矩阵 glMatrixMode(GL_MODELVIEW); // 重置投影矩阵 glLoadIdentity(); } // 绘制立方体 void GLWidget::drawCube() { glBegin(GL_QUAD_STRIP); //填充凸多边形 glColor3f(1, 0, 0); glVertex3f(0.0f, 0.0f, 0.0f); glColor3f(1, 1, 0); glVertex3f(0.0f, 1.0f, 0.0f); glColor3f(0, 1, 0); glVertex3f(1.0f, 0.0f, 0.0f); glColor3f(0, 1, 1); glVertex3f(1.0f, 1.0f, 0.0f); glColor3f(1, 0, 0); glVertex3f(1.0f, 0.0f, -1.0f); glColor3f(1, 1, 0); glVertex3f(1.0f, 1.0f, -1.0f); glColor3f(0, 1, 0); glVertex3f(0.0f, 0.0f, -1.0f); glColor3f(0, 1, 1); glVertex3f(0.0f, 1.0f, -1.0f); glColor3f(1, 0, 0); glVertex3f(0.0f, 0.0f, 0.0f); glColor3f(1, 1, 0); glVertex3f(0.0f, 1.0f, 0.0f); glEnd(); glBegin(GL_QUAD_STRIP); glColor3f(0, 0, 1); glVertex3f(0.0f, 0.0f, 0.0f); glColor3f(1, 0, 1); glVertex3f(1.0f, 0.0f, 0.0f); glColor3f(0, 1, 0); glVertex3f(0.0f, 0.0f, -1.0f); glColor3f(1, 0, 0); glVertex3f(1.0f, 0.0f, -1.0f); glColor3f(1, 1, 0); glVertex3f(0.0f, 1.0f, 0.0f); glColor3f(1, 0, 1); glVertex3f(1.0f, 1.0f, 0.0f); glColor3f(0, 0, 1); glVertex3f(0.0f, 1.0f, -1.0f); glColor3f(1, 0, 0); glVertex3f(1.0f, 1.0f, -1.0f); glEnd(); } // 绘制圆形 void GLWidget::drawCircle() { glBegin(GL_TRIANGLE_FAN); //扇形连续填充三角形串 glVertex3f(0.0f, 0.0f, 0.0f); int i = 0; for (i = 0; i <= 360; i += 15) { float p = i * 3.14 / 180; glColor3f(sin(p), cos(p), tan(p)); glVertex3f(sin(p), cos(p), 0.0f); } glEnd(); } // 绘制圆柱体 void GLWidget::drawCylinder() { // 利用三角形和四边形等基本图元绘制底面圆圆心在坐标原点， 半径为 r，高为 h，方向沿 z 轴方向的圆柱； // 侧面用多个四边形,底面用多个三角形来表示 glBegin(GL_QUAD_STRIP);//连续填充四边形串 int i = 0; for (i = 0; i <= 360; i += 15) { float p = i * 3.14 / 180; glVertex3f(sin(p), cos(p), 1.0f); glVertex3f(sin(p), cos(p), 0.0f); } glEnd(); //bottom circle glColor3f(1, 0, 0); drawCircle(); glTranslatef(0, 0, 1); //top circle glColor3f(0, 0, 1); drawCircle(); glColor3f(0, 1, 0); } // 绘制圆锥体 void GLWidget::drawCone() { glBegin(GL_QUAD_STRIP);//连续填充四边形串 int i = 0; for (i = 0; i <= 360; i += 15) { float p = i * 3.14 / 180; glColor3f(sin(p), cos(p), 1.0f); glVertex3f(0, 0, 1.0f); glVertex3f(sin(p), cos(p), 0.0f); } glEnd(); //bottom circle glColor3f(0, 1, 1); drawCircle(); } // 绘制四面体等 void GLWidget::drawTetrahedron() { glBegin(GL_QUADS); glNormal3f(0, 0, -1); glColor3f(1.0, 0.0, 0.0); glVertex3f(-1, -1, 0); glColor3f(0.0, 1.0, 0.0); glVertex3f(-1, 1, 0); glColor3f(0.0, 0.0, 1.0); glVertex3f(1, 1, 0); glColor3f(1.0, 1.0, 0.0); glVertex3f(1, -1, 0); glEnd(); glBegin(GL_TRIANGLES); glNormal3f(0, -1, 0.707); glColor3f(0.0, 1.0, 1.0); glVertex3f(-1, -1, 0); glColor3f(1.0, 0.0, 1.0); glVertex3f(1, -1, 0); glColor3f(1.0, 0.0, 1.0); glVertex3f(0, 0, 1.2); glEnd(); glBegin(GL_TRIANGLES); glNormal3f(1, 0, 0.707); glColor3f(0.0, 1.0, 1.0); glVertex3f(1, -1, 0); glColor3f(1.0, 0.0, 1.0); glVertex3f(1, 1, 0); glColor3f(1.0, 0.0, 1.0); glVertex3f(0, 0, 1.2); glEnd(); glBegin(GL_TRIANGLES); glNormal3f(0, 1, 0.707); glColor3f(0.0, 1.0, 1.0); glVertex3f(1, 1, 0); glColor3f(1.0, 0.0, 1.0); glVertex3f(-1, 1, 0); glColor3f(1.0, 0.0, 1.0); glVertex3f(0, 0, 1.2); glEnd(); glBegin(GL_TRIANGLES); glNormal3f(-1, 0, 0.707); glColor3f(1.0, 0.0, 1.0); glVertex3f(-1, 1, 0); glColor3f(0.0, 1.0, 1.0); glVertex3f(-1, -1, 0); glColor3f(1.0, 0.0, 0.0); glVertex3f(0, 0, 1.2); glEnd(); } // 绘制球体 // 球心坐标为（x，y，z），球的半径为radius，M，N分别表示球体的横纵向被分成多少份 void GLWidget::drawSphere(GLfloat xx, GLfloat yy, GLfloat zz, GLfloat radius, GLfloat M, GLfloat N) { // 选择使用的纹理 glBindTexture(GL_TEXTURE_2D, texture[0]); float step_z = PI / M; float step_xy = 2 * PI / N; float x[4], y[4], z[4]; float angle_z = 0.0; float angle_xy = 0.0; int i = 0, j = 0; glBegin(GL_QUADS); for(i = 0; i < M; i++) { angle_z = i * step_z; for(j = 0; j < N; j++) { angle_xy = j * step_xy; x[0] = radius * sin(angle_z) * cos(angle_xy); y[0] = radius * sin(angle_z) * sin(angle_xy); z[0] = radius * cos(angle_z); x[1] = radius * sin(angle_z + step_z) * cos(angle_xy); y[1] = radius * sin(angle_z + step_z) * sin(angle_xy); z[1] = radius * cos(angle_z + step_z); x[2] = radius * sin(angle_z + step_z) * cos(angle_xy + step_xy); y[2] = radius * sin(angle_z + step_z) * sin(angle_xy + step_xy); z[2] = radius * cos(angle_z + step_z); x[3] = radius * sin(angle_z) * cos(angle_xy + step_xy); y[3] = radius * sin(angle_z) * sin(angle_xy + step_xy); z[3] = radius * cos(angle_z); for(int k = 0; k < 4; k++) { glColor3f(sin(angle_z), cos(angle_z), tan(angle_z)); //glTexCoord2f(0.1f, 0.1f); glVertex3f(xx + x[k], yy + y[k], zz + z[k]); } } } glEnd(); } // 绘制圆环 // 大半径Radius，小半径TubeRadius，边数Sides， 环数Rings void GLWidget::DrawTorus(double Radius, double TubeRadius, int Sides, int Rings) { double sideDelta = 2.0 * PI / Sides; double ringDelta = 2.0 * PI / Rings; double theta = 0; double cosTheta = 1.0; double sinTheta = 0.0; double phi, sinPhi, cosPhi; double dist; glColor3f(1, 0, 0); for (int i = 0; i < Rings; i++) { double theta1 = theta + ringDelta; double cosTheta1 = cos(theta1); double sinTheta1 = sin(theta1); glBegin(GL_QUAD_STRIP); phi = 0; for (int j = 0; j <= Sides; j++) { phi = phi + sideDelta; cosPhi = cos(phi); sinPhi = sin(phi); dist = Radius + (TubeRadius * cosPhi); glNormal3f(cosTheta * cosPhi, sinTheta * cosPhi, sinPhi); glColor3f(cosTheta, sinTheta, sinPhi); glVertex3f(cosTheta * dist, sinTheta * dist, TubeRadius * sinPhi); glNormal3f(cosTheta1 * cosPhi, sinTheta1 * cosPhi, sinPhi); glColor3f(cosTheta1, sinTheta1, sinPhi); glVertex3f(cosTheta1 * dist, sinTheta1 * dist, TubeRadius * sinPhi); } glEnd(); theta = theta1; cosTheta = cosTheta1; sinTheta = sinTheta1; } } // 加载纹理 void GLWidget::loadGLTextures() { QImage tex1, buf1; QImage tex2, buf2; if (!buf1.load(":/data/qt-logo.jpg")) { // 如果载入不成功，自动生成一个128*128的32位色的绿色图片。 qWarning("Could not read image file!"); QImage dummy(128, 128, QImage::Format_RGB32); dummy.fill(Qt::green); buf1 = dummy; } if (!buf2.load(":/data/qt-wood.jpg")) { // 如果载入不成功，自动生成一个128*128的32位色的绿色图片。 qWarning("Could not read image file!"); QImage dummy(128, 128, QImage::Format_RGB32); dummy.fill(Qt::green); buf2 = dummy; } //***********************************************// // 纹理0：qt-logo //***********************************************// //转换成纹理类型 tex1 = QGLWidget::convertToGLFormat(buf1); // 创建纹理 glGenTextures(1, &texture[0]); // 使用来自位图数据生成的典型纹理,将纹理名字texture[0]绑定到纹理目标上 glBindTexture(GL_TEXTURE_2D, texture[0]); // WRAP参数：纹理坐标超出[0,0]到[1,1]的范围该怎么处理呢？ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP); // Filter参数：纹理坐标映射到纹素位置(127.34,255.14)该怎么办? glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); // 纹理环境 glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE); // 将纹素数组从CPU传至GPU并且设置为当前纹理。 // 在处理单一纹理时，你可以用，负责效率非常低。 // 多纹理时可以参见纹理绑定。 glTexImage2D(GL_TEXTURE_2D, 0, 3, tex1.width(), tex1.height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, tex1.bits()); //***********************************************// // 纹理0：qt-logo //***********************************************// tex2 = QGLWidget::convertToGLFormat(buf2); glGenTextures(1, &texture[1]); glBindTexture(GL_TEXTURE_2D, texture[1]); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE); glTexImage2D(GL_TEXTURE_2D, 0, 3, tex2.width(), tex2.height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, tex2.bits()); // 使用纹理 // 首先调用glEnable( GL_TEXTURE_2D )，来启用2D纹理; // 然后绘制图形，并且为每个顶点指定ST坐标; // 最后调用glDisable( GL_TEXTURE_2D ). } // 场景渲染 void GLWidget::renderScene(void) { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); glPushMatrix(); renderBasicShape(); glPopMatrix(); glPushMatrix(); glTranslatef(-3, 0, 0); renderTextureCube(); glPopMatrix(); glPushMatrix(); glTranslatef(3, 0, 0); renderTextureCylinder(); glPopMatrix(); } // 渲染基本图形 void GLWidget::renderBasicShape() { static float fRotAngle = 0.0f; fRotAngle += ROT_DELTA; if (fRotAngle > 360) fRotAngle = 0; glPushMatrix(); glColor3f(0, 1, 0); glTranslatef(-3, 3, -12); glRotatef(fRotAngle, 1, 1 , 1); drawCylinder(); glPopMatrix(); glPushMatrix(); glColor3f(1, 0, 0); glTranslatef(0, 3, -12); glRotatef(fRotAngle, 1, 1 , 1); drawTetrahedron(); glPopMatrix(); glPushMatrix(); glColor3f(1, 0, 0); glTranslatef(3, 3, -12); glRotatef(fRotAngle, 1, 1, 1); drawCircle(); glPopMatrix(); glPushMatrix(); glColor3f(1, 0, 0); glTranslatef(0, 0, -15); glRotatef(fRotAngle, 0, 1, 0); drawSphere(); glPopMatrix(); glPushMatrix(); glColor3f(0, 1, 1); glTranslatef(-3, -3, -12); glRotatef(fRotAngle, 1, 1, 1); drawCube(); glPopMatrix(); glPushMatrix(); glColor3f(1, 0, 1); glTranslatef(0, -3, -12); glRotatef(fRotAngle, 1, 1, 1); DrawTorus(); glPopMatrix(); glPushMatrix(); glColor3f(1, 1, 0); glTranslatef(3, -3, -12); glRotatef(fRotAngle, 1, 1, 1); drawCone(); glPopMatrix(); } // 渲染纹理 void GLWidget::renderTextureCube() { // 纹理映射 glColor3f(1.0, 1.0, 1.0); glTranslatef(0.0f, 0.0f, -12.0f); glRotatef(xRot, 1.0, 0.0, 0.0); glRotatef(yRot, 0.0, 1.0, 0.0); glRotatef(zRot, 0.0, 0.0, 1.0); // 使用来自位图数据生成的典型纹理,将纹理名字texture[0]绑定到纹理目标上 glBindTexture(GL_TEXTURE_2D, texture[0]); glBegin( GL_QUADS ); glTexCoord2f( 0.0, 0.0 ); glVertex3f( -1.0, -1.0, 1.0 ); glTexCoord2f( 1.0, 0.0 ); glVertex3f( 1.0, -1.0, 1.0 ); glTexCoord2f( 1.0, 1.0 ); glVertex3f( 1.0, 1.0, 1.0 ); glTexCoord2f( 0.0, 1.0 ); glVertex3f( -1.0, 1.0, 1.0 ); glTexCoord2f( 1.0, 0.0 ); glVertex3f( -1.0, -1.0, -1.0 ); glTexCoord2f( 1.0, 1.0 ); glVertex3f( -1.0, 1.0, -1.0 ); glTexCoord2f( 0.0, 1.0 ); glVertex3f( 1.0, 1.0, -1.0 ); glTexCoord2f( 0.0, 0.0 ); glVertex3f( 1.0, -1.0, -1.0 ); glTexCoord2f( 0.0, 1.0 ); glVertex3f( -1.0, 1.0, -1.0 ); glTexCoord2f( 0.0, 0.0 ); glVertex3f( -1.0, 1.0, 1.0 ); glTexCoord2f( 1.0, 0.0 ); glVertex3f( 1.0, 1.0, 1.0 ); glTexCoord2f( 1.0, 1.0 ); glVertex3f( 1.0, 1.0, -1.0 ); glTexCoord2f( 1.0, 1.0 ); glVertex3f( -1.0, -1.0, -1.0 ); glTexCoord2f( 0.0, 1.0 ); glVertex3f( 1.0, -1.0, -1.0 ); glTexCoord2f( 0.0, 0.0 ); glVertex3f( 1.0, -1.0, 1.0 ); glTexCoord2f( 1.0, 0.0 ); glVertex3f( -1.0, -1.0, 1.0 ); glTexCoord2f( 1.0, 0.0 ); glVertex3f( 1.0, -1.0, -1.0 ); glTexCoord2f( 1.0, 1.0 ); glVertex3f( 1.0, 1.0, -1.0 ); glTexCoord2f( 0.0, 1.0 ); glVertex3f( 1.0, 1.0, 1.0 ); glTexCoord2f( 0.0, 0.0 ); glVertex3f( 1.0, -1.0, 1.0 ); glTexCoord2f( 0.0, 0.0 ); glVertex3f( -1.0, -1.0, -1.0 ); glTexCoord2f( 1.0, 0.0 ); glVertex3f( -1.0, -1.0, 1.0 ); glTexCoord2f( 1.0, 1.0 ); glVertex3f( -1.0, 1.0, 1.0 ); glTexCoord2f( 0.0, 1.0 ); glVertex3f( -1.0, 1.0, -1.0 ); glEnd(); xRot += ROT_DELTA; if (xRot > 360) xRot = 0; yRot += ROT_DELTA; if (yRot > 360) yRot = 0; zRot += ROT_DELTA; if (zRot > 360) zRot = 0; } void GLWidget::renderTextureCylinder() { // 纹理映射 glTranslatef(0.0f, 0.0f, -12.0f); glRotatef(xRot, 1.0, 0.0, 0.0); //glRotatef(yRot, 0.0, 1.0, 0.0); //glRotatef(zRot, 0.0, 0.0, 1.0); // 选择使用的纹理 glBindTexture(GL_TEXTURE_2D, texture[1]); // 利用三角形和四边形等基本图元绘制底面圆圆心在坐标原点， 半径为 r，高为 h，方向沿 z 轴方向的圆柱； // 侧面用多个四边形,底面用多个三角形来表示 glBegin(GL_QUAD_STRIP);//连续填充四边形串 int i = 0; for (i = 0; i <= 360; i += 15) { float p = i * 3.14 / 180; //p和圆周是相对应的， 这里让纹理的横坐标随圆周扫过的角度一起改变，就能够将纹理图“刷”上去了， //而纵坐标设置为图像的高度和纹理高度的对应，这里合适的参数是根据实际测试得到的 glTexCoord2f(p / 10, 0.1f); glVertex3f(sin(p), cos(p), 1.0f); //这个 1.0f指定的是高度h glTexCoord2f(p / 10, 0.0f); glVertex3f(sin(p), cos(p), 0.0f); } glEnd(); //bottom circle glBegin(GL_TRIANGLE_FAN); //扇形连续填充三角形串 glTexCoord2f(0.0f, 0.0f); //将纹理图(0, 0)映射到圆心 glVertex3f(0.0f, 0.0f, 0.0f); for (i = 0; i <= 360; i += 15) { float p = i * 3.14 / 180; glTexCoord2f(1.0f, 0.0f); //将纹理图(1, 0)映射到圆周 glVertex3f(sin(p), cos(p), 0.0f); } glEnd(); glTranslatef(0, 0, 1); //设定高度为1，画上底面 //top circle glBegin(GL_TRIANGLE_FAN); //扇形连续填充三角形串 glTexCoord2f(0.0f, 0.0f); //将纹理图(0, 0)映射到圆心 glVertex3f(0.0f, 0.0f, 0.0f); for (i = 0; i <= 360; i += 15) { float p = i * 3.14 / 180; glTexCoord2f(1.0f, 0.0f); //将纹理图(1, 0)映射到圆周 glVertex3f(sin(p), cos(p), 0.0f); } glEnd(); xRot += ROT_DELTA; if (xRot > 360) xRot = 0; yRot += ROT_DELTA; if (yRot > 360) yRot = 0; zRot += ROT_DELTA; if (zRot > 360) zRot = 0; } |
主函数调用
main.cpp
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#include "GLWidget.h"
#include <QApplication> #include <QObject> int main(int argc, char *argv[]) { QApplication a(argc, argv); GLWidget w; w.resize(600, 600); w.setWindowTitle(QObject::tr("Michael\'s OpenGL Framework")); w.show(); return a.exec(); } |
运行效果
