【OpenGL】OpenGL 2D平移与旋转

#include "stdafx.h" #include <windows.h> #include <glew.h> #include "glut.h" #include <stdlib.h> #include <math.h> #include <stdio.h> #include <string> #include "png.h" #include "zlib.h" #include <glfw3.h> #pragma comment(lib, "glut.lib") #pragma comment(lib, "glut32.lib") #pragma comment(lib, "libpng16.lib") #pragma comment(lib, "zlib.lib") #pragma comment (lib,"glew32d.lib") #pragma comment (lib,"glfw3.lib") #pragma comment (lib,"glfw3dll.lib")

平移：

GLfloat rtx = 0.0f, rty = 0.0f, rtz = 0.0f; GLfloat step = 0.05; GLfloat exp1 = 1e-3; void init() { glLoadIdentity(); glClearColor(0.0, 0.0, 0.0, 0.0); } void draw(void) { glClear(GL_COLOR_BUFFER_BIT); glPushMatrix(); printf("%f %f %f\n", rtx, rty, rtz); glTranslatef(rtx, rty, rtz); glBegin(GL_QUADS); glColor3f(1.0f, 0.0f, 0.0f); glVertex2f(-0.5f, 0.5f); glColor3f(0.0f, 1.0f, 0.0f); glVertex2f(0.5f, 0.5f); glColor3f(0.0f, 0.0f, 1.0f); glVertex2f(0.5f, -0.5f); glColor3f(0.5f, 0.5f, 0.5f); glVertex2f(-0.5f, -0.5f); glEnd(); glPopMatrix(); glutSwapBuffers(); } /* special key defined in glut #define GLUT_KEY_F1 1 #define GLUT_KEY_F2 2 #define GLUT_KEY_F3 3 #define GLUT_KEY_F4 4 #define GLUT_KEY_F5 5 #define GLUT_KEY_F6 6 #define GLUT_KEY_F7 7 #define GLUT_KEY_F8 8 #define GLUT_KEY_F9 9 #define GLUT_KEY_F10 10 #define GLUT_KEY_F11 11 #define GLUT_KEY_F12 12 #define GLUT_KEY_LEFT 100 #define GLUT_KEY_UP 101 #define GLUT_KEY_RIGHT 102 #define GLUT_KEY_DOWN 103 #define GLUT_KEY_PAGE_UP 104 #define GLUT_KEY_PAGE_DOWN 105 #define GLUT_KEY_HOME 106 #define GLUT_KEY_END 107 #define GLUT_KEY_INSERT 108 */ void processKeyBoard(int key, int x, int y) { switch (key) { case GLUT_KEY_LEFT: if (rtx - step > -0.53)rtx -= step; break; case GLUT_KEY_RIGHT: if (rtx + step < 0.53)rtx += step; break; case GLUT_KEY_UP: if (rty + step < 0.53)rty += step; break; case GLUT_KEY_DOWN: if (rty - step > -0.53)rty -= step; break; default: break; } glutPostRedisplay(); return; } int main(int argc, char *argv[]) { glutInit(&argc, argv); glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE); glutInitWindowPosition(100, 100); glutInitWindowSize(600, 600); glutCreateWindow("test"); init(); glutDisplayFunc(draw); //glutIdleFunc(move); glutSpecialFunc(processKeyBoard); glutMainLoop(); return 0; }

旋转：

static GLfloat xRot = 0.0f; static GLfloat yRot = 0.0f; //确定多边形绕法的方向 bool bWinding = true; void SetupRC(void) { //设置窗口背景颜色为黑色 glClearColor(0.0f, 0.0f, 0.0f, 1.0f); } void ChangeSize(GLint w, GLint h) { if (h == 0) h = 1; glViewport(0, 0, w, h); glMatrixMode(GL_PROJECTION); glLoadIdentity(); if (w <= h) { glOrtho(-100.0f, 100.0f * h / w, -100.0f, 100.0f * h / w, -100.0f, 100.0f); } else { glOrtho(-100.0f * w / h, 100.0f * w / h, -100.0f, 100.0f, -100.0f, 100.0f); } glMatrixMode(GL_MODELVIEW); glLoadIdentity(); } //在窗口中绘制图形 void RenderScene(void) { glClear(GL_COLOR_BUFFER_BIT); //旋转图形 glPushMatrix(); glRotatef(xRot, 1.0f, 0.0f, 0.0f); glRotatef(yRot, 0.0f, 1.0f, 0.0f); //设置点的大小以及线宽 glPointSize(5.0f); glLineWidth(5.0f); //设置多边形绕法的方向是顺时针还是逆时针 if (bWinding) { glFrontFace(GL_CW); } else { glFrontFace(GL_CCW); } //绘制三角形 glBegin(GL_TRIANGLES); glColor3f(0.0f, 1.0f, 0.0f); glVertex3f(0.0f, 60.0f, 0.0f); glColor3f(1.0f, 0.0f, 0.0f); glVertex3f(-60.0f, -60.0f, 0.0f); glColor3f(0.0f, 0.0f, 1.0f); glVertex3f(60.0f, -60.0f, 0.0f); glEnd(); glPopMatrix(); glutSwapBuffers(); } void SpecialKeys(GLint key, GLint x, GLint y) { switch (key) { case GLUT_KEY_UP: xRot -= 5.0f; break; case GLUT_KEY_DOWN: xRot += 5.0f; break; case GLUT_KEY_LEFT: yRot -= 5.0f; break; case GLUT_KEY_RIGHT: yRot += 5.0f; break; default: break; } if (xRot > 356.0f) xRot = 0.0f; if (xRot < -1.0f) xRot = 355.0f; if (yRot > 356.0f) yRot = 0.0f; if (yRot < -1.0f) yRot = 355.0f; glutPostRedisplay();//重回窗口 } void ProcessMenu(GLint value) { switch (value) { case 1: //修改多边形正面为填充模式 glPolygonMode(GL_FRONT, GL_FILL); break; case 2: glPolygonMode(GL_FRONT, GL_LINE); break; case 3: glPolygonMode(GL_FRONT, GL_POINT); break; case 4: glPolygonMode(GL_FRONT, GL_FILL); break; case 5: glPolygonMode(GL_FRONT, GL_LINE); break; case 6: glPolygonMode(GL_FRONT, GL_POINT); break; case 7: glShadeModel(GL_FLAT); break; case 8: glShadeModel(GL_SMOOTH); break; case 9: bWinding = !bWinding; break; case 10: //以线条的框架显示图 glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); break; default: break; } } int main(int argc, char *argv[]) { GLint nModeMenu = 0; GLint nMainMenu = 0; GLint nColorMenu = 0; glutInit(&argc, argv); glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB); glutCreateWindow("多边形演示"); glutReshapeFunc(ChangeSize); glutSpecialFunc(SpecialKeys); glutDisplayFunc(RenderScene); //创建一个子菜单 nModeMenu = glutCreateMenu(ProcessMenu); glutAddMenuEntry("正面多边形填充模式", 1); glutAddMenuEntry("正面线框模型", 2); glutAddMenuEntry("正面点模式", 3); glutAddMenuEntry("反面多边形填充模式", 1); glutAddMenuEntry("反面线框模型", 2); glutAddMenuEntry("反面点模式", 3); glutAddMenuEntry("线条框架", 10); //增加一个子菜单 nColorMenu = glutCreateMenu(ProcessMenu); glutAddMenuEntry("平面明暗模式", 7); glutAddMenuEntry("光滑明暗模式", 8); //创建主菜单 nMainMenu = glutCreateMenu(ProcessMenu); glutAddSubMenu("多边形模式", nModeMenu); glutAddSubMenu("颜色模式", nColorMenu); glutAddMenuEntry("改变绕法", 9); //将创建菜单与右键关联，即把菜单设置为右键弹出式菜单 glutAttachMenu(GLUT_RIGHT_BUTTON); SetupRC(); glutMainLoop(); }