基于opengl的RoundBox绘制

实现了16种roundBox，见图

 

核心绘制码在RoundBox.h文件：

 #ifndef ROUNDBOXRENDER_H#define ROUNDBOXRENDER_H// 7/8/2010 RYF// QQ: 546952710// Email: [e-mail] RoundBoxRender{// 产生一个渐变的效果：//shadetop叠加top//shadedown叠加到down 可以为负//rad为圆角的半径/* linear horizontal shade within button or in outline *//* view2d scrollers use it */static void gl_round_box_shade(int mode, float minx, float miny, float maxx, float maxy, float rad, float shadetop, float shadedown){float vec[7][2]= {{0.195, 0.02}, {0.383, 0.067}, {0.55, 0.169}, {0.707, 0.293},{0.831, 0.45}, {0.924, 0.617}, {0.98, 0.805}};float div= maxy-miny;float coltop[3], coldown[3], color[4];int a;/* mult */for(a=0; a<7; a++) {vec[a][0]*= rad; vec[a][1]*= rad;}/* get current color, needs to be outside of glBegin/End */glGetFloatv(GL_CURRENT_COLOR, color);/* 'shade' defines strength of shading */coltop[0]= color[0]+shadetop; if(coltop[0]>1.0) coltop[0]= 1.0;coltop[1]= color[1]+shadetop; if(coltop[1]>1.0) coltop[1]= 1.0;coltop[2]= color[2]+shadetop; if(coltop[2]>1.0) coltop[2]= 1.0;coldown[0]= color[0]+shadedown; if(coldown[0]<0.0) coldown[0]= 0.0;coldown[1]= color[1]+shadedown; if(coldown[1]<0.0) coldown[1]= 0.0;coldown[2]= color[2]+shadedown; if(coldown[2]<0.0) coldown[2]= 0.0;glShadeModel(GL_SMOOTH);glBegin(mode);/* start with corner right-bottom */if(roundboxtype & 4) {round_box_shade_col(coltop, coldown, 0.0);glVertex2f(maxx-rad, miny);for(a=0; a<7; a++) {round_box_shade_col(coltop, coldown, vec[a][1]/div);glVertex2f(maxx-rad+vec[a][0], miny+vec[a][1]);}round_box_shade_col(coltop, coldown, rad/div);glVertex2f(maxx, miny+rad);}else {round_box_shade_col(coltop, coldown, 0.0);glVertex2f(maxx, miny);}/* corner right-top */if(roundboxtype & 2) {round_box_shade_col(coltop, coldown, (div-rad)/div);glVertex2f(maxx, maxy-rad);for(a=0; a<7; a++) {round_box_shade_col(coltop, coldown, (div-rad+vec[a][1])/div);glVertex2f(maxx-vec[a][1], maxy-rad+vec[a][0]);}round_box_shade_col(coltop, coldown, 1.0);glVertex2f(maxx-rad, maxy);}else {round_box_shade_col(coltop, coldown, 1.0);glVertex2f(maxx, maxy);}/* corner left-top */if(roundboxtype & 1) {round_box_shade_col(coltop, coldown, 1.0);glVertex2f(minx+rad, maxy);for(a=0; a<7; a++) {round_box_shade_col(coltop, coldown, (div-vec[a][1])/div);glVertex2f(minx+rad-vec[a][0], maxy-vec[a][1]);}round_box_shade_col(coltop, coldown, (div-rad)/div);glVertex2f(minx, maxy-rad);}else {round_box_shade_col(coltop, coldown, 1.0);glVertex2f(minx, maxy);}/* corner left-bottom */if(roundboxtype & 8) {round_box_shade_col(coltop, coldown, rad/div);glVertex2f(minx, miny+rad);for(a=0; a<7; a++) {round_box_shade_col(coltop, coldown, (rad-vec[a][1])/div);glVertex2f(minx+vec[a][1], miny+rad-vec[a][0]);}round_box_shade_col(coltop, coldown, 0.0);glVertex2f(minx+rad, miny);}else {round_box_shade_col(coltop, coldown, 0.0);glVertex2f(minx, miny);}glEnd();glShadeModel(GL_FLAT);}static void setType(int nType){ roundboxtype = nType % 16;}protected:static void round_box_shade_col(float *col1, float *col2, float fac){float col[3];col[0]= (fac*col1[0] + (1.0-fac)*col2[0]);col[1]= (fac*col1[1] + (1.0-fac)*col2[1]);col[2]= (fac*col1[2] + (1.0-fac)*col2[2]);glColor3fv(col);}static int roundboxtype;};int RoundBoxRender::roundboxtype = 3;#endif

gl_round_box_shade中mode支持：GL_LINE_LOOP，GL_POLYGON，GL_TRIANGLE_FAN

round_box_shade_col：col1颜色和col2颜色，根据混合因子fac进行混合，产生中间颜色。

 

主程序基于glut：

#include <cstdio>#include <cstdlib>#include <GL/glut.h>#include <cmath>#include <ctime>//#include "BezierLinkRender.h"#include "RoundBoxRender.h"////////////////////////////////////////////////////globalGLuint gColorStable[] = {(0xFF0000),//red (0xDC143C),//crimson(0x9400D3),//violet(0xFFA000),//orange(0xFFFF00),//yellow(0xFFD700),//glod(0x00FF00),//green(0x90FF90),//lightgreen(0x006400),//darkgreen(0x556B2F),//olivegreen//very good color绿橄榄(0x0000FF),//blue(0x00008B),//darkblue(0x4169E1),//royalblue(0x5555FF),//skyblue(0x191970),//midnightbue(0xFF00FF),//fuchsia(0x00FFFF),//aqua(0xffb6c1),//pink(0xFF91A4),//salmonpink(0x30D5C8),//turquoise(0x008080),//darkturpuoise(0xA9A9A9),//gray(0xD3D3D3),//lightgray(0x808080)//darkgray};float g_fWidth = 500;float g_fHeight = 500;float g_fDepth = 100;float g_fAngle = .0;intgRoundboxtype = 0;//////////////////////////////////////////////////////////////////////////void renderBitmapString2D(float x, float y, void *font, char *string);void getColorFromTable(GLuint rgb, float vec[3]);void init(void) {RoundBoxRender::setType(gRoundboxtype);printf("%d/n", gRoundboxtype);glClearColor (0.9, 0.9, 0.9, 0.0);glShadeModel (GL_SMOOTH);}void display(void){const float slotSize = 30.f;const float slotColor[] = {0.8f, 0.8f, 0.8f};const float slotShadowSize = 2.0f;const float slotShadowAlpha = 0.7;glClear (GL_COLOR_BUFFER_BIT);glColor3f (1.0, 1.0, 1.0);glMatrixMode(GL_PROJECTION);glLoadIdentity();glOrtho(0, g_fWidth, 0, g_fHeight, 0, g_fDepth);glMatrixMode(GL_MODELVIEW);glLoadIdentity();glTranslatef(80.f, 80.f, 0.f);//整体平移int xPos(0);int yPos(0);int xOffset(0);int yOffset(0);for (int i=0; i<16; i++){char buffer[10] = {'/0'};itoa (i,buffer,10);int fontWidOffset = i>10 ? 12 : 5;//估算量int fontHghOffset = 10;//估算量int boxSize = 60;float colorVec[3];getColorFromTable(gColorStable[i], colorVec);glColor3fv(colorVec);RoundBoxRender::setType(i);yOffset = i/4;xOffset = i%4;glPushMatrix();{glTranslatef(xPos+xOffset*100, yPos+yOffset*100, 0.f);RoundBoxRender::gl_round_box_shade(GL_POLYGON, 0, 0, boxSize, boxSize, 10, 0.3, 0);glColor3f(0.f, 0.f, 0.0f);renderBitmapString2D(boxSize/2-fontWidOffset, boxSize/2-fontHghOffset, GLUT_BITMAP_TIMES_ROMAN_24, buffer);}glPopMatrix();}//glColor3f(1.0f, 1.0f, 0.0f);//ui_draw_link_bezier(&gRect);glutSwapBuffers();}void reshape (int w, int h){glViewport (0, 0, (GLsizei) w, (GLsizei) h); glMatrixMode (GL_PROJECTION);glLoadIdentity ();gluPerspective(60,1.0,1.5,20);glMatrixMode (GL_MODELVIEW);}void keyboard(unsigned char key, int x, int y){switch (key) {case 27:exit(0);break;}glutPostRedisplay();}void mouse(int button, int state, int x, int y){if(button==GLUT_LEFT_BUTTON)switch(state){case GLUT_DOWN:break;case GLUT_UP:break;}glutPostRedisplay();}int main(int argc, char** argv){glutInit(&argc, argv);glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB);glutInitWindowSize (500, 500); glutInitWindowPosition (100, 100);glutCreateWindow (argv[0]);init ();glutDisplayFunc(display); glutReshapeFunc(reshape);glutKeyboardFunc(keyboard);glutMouseFunc( mouse );glutMainLoop();return 0;}void renderBitmapString2D(float x, float y, void *font, char *string){char *c;// set position to start drawing fontsglRasterPos2f(x, y);// loop all the characters in the stringfor (c=string; *c != '/0'; c++) {glutBitmapCharacter(font, *c);}}void getColorFromTable(GLuint rgb, float vec[3]){GLubyte r = GLubyte ((rgb >> 16) & 0xFF);GLubyte g = GLubyte ((rgb >> 8) & 0xFF);GLubyte b = GLubyte (rgb & 0xFF);vec[0] = r / 255.0f;vec[1] = g / 255.0f;vec[2] = b / 255.0f;}