我希望每个立方体都有一个随机的颜色，但是有了这段代码，颜色一直在变化
int espacioX = -500;
int espacioY = -500;
for(int i=1; i<=100; i++){
for(int j=1; j<=100; j++){
randomR = (double)rand() / (RAND_MAX);
randomG = (double)rand() / (RAND_MAX);
randomB = (double)rand() / (RAND_MAX);
glColor3f(randomR,randomG,randomB);
glTranslatef(espacioX,espacioY,0);
glutSolidCube(9);
glTranslatef(-espacioX,-espacioY,0);
espacioX+=10;
}
glTranslatef(-1000,0,0);
espacioY+=10;
}
在程序运行时如何使它们保持相同的颜色？
编辑： 这是完整的代码：
#include <windows.h>
/***** OpenGL library imports. *****/
#include<gl\glut.h> //basic header file for OpenGL
//#include <gl\glaux.h> // Header File For The Glaux Library
/***** C library imports. *****/
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
int ScreenWidth = 0;
int ScreenHeight = 0;
int last_x = 0, last_y = 0,left = 1,middle = 0,right = 0;
int zoom_y = 0;
int anglex=0, angley=0, anglez=0;
int lookfrom=450;
int ang=0;
void myGlutKeyboard(unsigned char Key, int x, int y)
{
printf("%5d\n",Key);
glutPostRedisplay();
}
void init_GL_params()
{
static GLfloat light_ambient[] = { .250, .250, .250, .250 };
static GLfloat light_diffuse[] = { .250, .250, .25, .250 };
static GLfloat light_specular[] = { .250, .250, .250, .250 };
static GLfloat light1_diffuse[] = { .250, .250, .250, .0 };
static GLfloat light1_specular[] = { .250, .250, .250, .0 };
glEnable (GL_LIGHTING);
glEnable (GL_LIGHT0);
glEnable (GL_LIGHT1);
glDisable (GL_TEXTURE_2D);
glDisable (GL_TEXTURE_GEN_S);
glDisable (GL_TEXTURE_GEN_T);
glShadeModel (GL_FLAT);
glEnable (GL_DEPTH_TEST);
glDepthFunc (GL_LESS);
glEnable (GL_CULL_FACE);
glCullFace (GL_BACK);
glFrontFace (GL_CCW);
glMatrixMode (GL_PROJECTION);
glLoadIdentity();
glLightfv (GL_LIGHT0, GL_AMBIENT, light_ambient);
glLightfv (GL_LIGHT0, GL_DIFFUSE, light_diffuse);
glLightfv (GL_LIGHT0, GL_SPECULAR, light_specular);
glLightfv(GL_LIGHT1, GL_DIFFUSE, light1_diffuse);
glLightfv(GL_LIGHT1, GL_SPECULAR, light1_specular);
glLightfv (GL_LIGHT1, GL_AMBIENT, light_ambient);
glColor3f (1.0, 1.0, 1.0);
}
void setLightPosition()
{
static GLfloat light_position[] = { 100, 200.0, 10, 1.0 };
static GLfloat light1_position[] = { -0.0, 300.0, 0.0, 1.0 };
// set the light position (for some reason we have to do this in model view.
glLightfv (GL_LIGHT0, GL_POSITION, light_position);
glLightfv(GL_LIGHT1, GL_POSITION, light1_position);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glEnable(GL_COLOR_MATERIAL);
}
void myGlutDisplay(void)
{
init_GL_params();
// clear the window
glClearColor (0,0,0,0); //Color de fondo R G B
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode (GL_MODELVIEW);
glLoadIdentity();
setLightPosition(); //Posici{on de la fuente de luz
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
gluPerspective(60.0f, 1.0, 1.0f, 10000.0f);
gluLookAt( //punto de vista
0 ,100 ,lookfrom , // desde donde veo xyz
0, 0, 0, // hacia donde veo xyz
0,1,0 );
glRotatef(anglex, 1.0, 0.0, 0.0);
glRotatef(angley, 0.0, 1.0, 0.0);
glRotatef(anglez, 0.0, 0.0, 1.0);
//Empieza a dibujar
int espacioX = 500;
int espacioY = 500;
double randomR, randomG, randomB;
for(int i=1; i<=100; i++){
for(int j=1; j<=100; j++){
randomR = (double)rand() / (RAND_MAX);
randomG = (double)rand() / (RAND_MAX);
randomB = (double)rand() / (RAND_MAX);
glColor3f(randomR,randomG,randomB);
glTranslatef(espacioX,espacioY,0);
glutSolidCube(9);
glTranslatef(-espacioX,-espacioY,0);
espacioX-=10;
}
glTranslatef(1000,0,0);
espacioY-=10;
}
glFlush(); // Flush The GL Pipeline
glutSwapBuffers();
}
void myGlutReshape2(int mWidth, int mHeight)
{
ScreenWidth = mWidth;
ScreenHeight = mHeight;
glViewport(0, 0, (GLsizei) ScreenWidth, (GLsizei) ScreenHeight);
glutPostRedisplay();
}
/****************************************************************/
void myGlutIdle(void)
{
glutPostRedisplay();
}
/***************************************************************/
void myGlutMouse(int button, int button_state, int x, int y){
if ( (button == GLUT_LEFT_BUTTON) && (button_state == GLUT_DOWN) )
{
last_x = x;
last_y = y;
left = 1;
middle = 0;
right = 0;
}
else if ((button == GLUT_RIGHT_BUTTON) && (button_state == GLUT_DOWN) )
{
zoom_y = y;
right = 1;
left = 0;
middle = 0;
}
}
void myGlutMotion(int x, int y){
if (left){
anglex+= (float) (y - last_y);
angley+= (float) (x - last_x);
last_x = x;
last_y = y;
}
if (right)
{
lookfrom += (y - zoom_y);
zoom_y = y;
}
}
void GlutInit(int argc, char** argv)
{
ScreenWidth = 700;
ScreenHeight = 700;
/****************************************/
/* Initialize GLUT and create window */
/****************************************/
glutInit(&argc, argv);
glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_STENCIL ); //set up the display as a double buffer using RGB values
glutInitWindowPosition(90, 50); //set the position of where you want the window to open
glutInitWindowSize(ScreenWidth, ScreenHeight); //set how big you want the initial window to be
glutCreateWindow("Testing Virtual Environment" ); //what do you want the window to be called (titlebar text)
//register callbacks
glutDisplayFunc(myGlutDisplay); //Register the display callback
glutReshapeFunc(myGlutReshape2); // -- Resize handler
glutKeyboardFunc(myGlutKeyboard); // -- Keyboard handler
glutMouseFunc(myGlutMouse); // -- Mouse Click handler
glutMotionFunc(myGlutMotion); // -- Mous motion handler
glutIdleFunc(myGlutIdle); // -- Idle handler
glFlush();
}
int main( int argc, char **argv )
{
GlutInit(argc, argv);
glutMainLoop();
return 0;
}
这是一个示例代码，抱歉，我只是发布了我编辑的部分。当我用特定的颜色制作立方体或球体时，它总是保持不变，因此我没有意识到这会一直刷新图像。我不太了解整个过程，所以不知道刷新图像的位置。
答案 0 :(得分：1)
似乎您在另一个循环中运行此代码，这意味着您每次重新绘制场景时都在计算随机变量，这将导致颜色发生变化，并且显而易见的解决方案是一次填充多维数据集列表，然后然后遍历列表，在每个场景刷新时绘制多维数据集。
但是，看不到代码的其余部分并不清楚。请提供更多信息，以便我们为您提供更好的答案。
答案 1 :(得分：1)
为什么不在SEED的开头将myGlutDisplay(void)设置为某个常数。这样一来，您就可以在每一帧中获得相同的随机值，而无需在代码中进行任何大的更改，例如：
void myGlutDisplay(void)
{
init_GL_params();
// clear the window
glClearColor (0,0,0,0); //Color de fondo R G B
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode (GL_MODELVIEW);
glLoadIdentity();
setLightPosition(); //Posici{on de la fuente de luz
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
gluPerspective(60.0f, 1.0, 1.0f, 10000.0f);
gluLookAt( //punto de vista
0 ,100 ,lookfrom , // desde donde veo xyz
0, 0, 0, // hacia donde veo xyz
0,1,0 );
glRotatef(anglex, 1.0, 0.0, 0.0);
glRotatef(angley, 0.0, 1.0, 0.0);
glRotatef(anglez, 0.0, 0.0, 1.0);
//Empieza a dibujar
int espacioX = 500;
int espacioY = 500;
double randomR, randomG, randomB;
srand(0x98765432); // this is the SEED
for(int i=1; i<=100; i++){
for(int j=1; j<=100; j++){
randomR = (double)rand() / (RAND_MAX);
randomG = (double)rand() / (RAND_MAX);
randomB = (double)rand() / (RAND_MAX);
glColor3f(randomR,randomG,randomB);
glTranslatef(espacioX,espacioY,0);
glutSolidCube(9);
glTranslatef(-espacioX,-espacioY,0);
espacioX-=10;
}
glTranslatef(1000,0,0);
espacioY-=10;
}
glFlush(); // Flush The GL Pipeline
glutSwapBuffers();
}
SEED的值将为您提供模式。因此，更改常数将更改颜色。注意错误的常数（例如0）会破坏rand()函数的随机性。