GLUT 程序仅适用于几帧
GLUT program only works for a few frames
我有一个我在 6 个多月前编写的程序，它使用了 GLUT 库。 6 个月前我写的时候它运行得非常好。从那以后我就没有使用过它，也没有以任何方式编辑过代码。
该程序有一些立方体以一些随机速度四处漂浮，它们会从它们所在环境的墙壁上反弹。可以使用箭头键和 panned/tilted 使用鼠标移动摄像机。可以通过单击向环境中添加更多的墙，然后可以使用箭头键调整这些墙的位置。
然而，尽管这在 6 个月前是有效的，但现在摄像机仅 pans/tilts 在程序的前几帧使用鼠标，使用箭头键移动摄像机也是如此。但是程序并没有冻结，我仍然可以看到立方体漂浮在周围，可以添加和调整位置的墙仍然可以移动。
是否有任何常见原因导致以前工作的 GLUT 程序只能在前几帧正常运行？
#include <iostream>
#include <GL/glut.h>
#include <Windows.h> //FOR CURSOR
#include <tgmath.h> //FOR MATHS
#include <fstream>
#include <string>
#include <time.h> //FOR THE TIME FOR RANDOM GENERATOR SEED
const int MAXMOLECULES = 1000000, MAXCUBOIDS = 10000, NUMBER_OF_PRESSURE_SENSORS = 3, MAX_RECORDING_TIME = 1000000;
int widthOfMonitor = glutGet( GLUT_SCREEN_WIDTH ), heightOfMonitor = glutGet( GLUT_SCREEN_HEIGHT ),
cuboidBuilding = 0;//IS A CUBE CURRENTLY BEING BUILT? 0 FOR NO, 1 FOR YES.
const float ORIGINAL_CAMERA_LOCATION[3] = { 0, 0, 0 }, //ORIGINAL CAMERA LOCATION
ORIGINAL_CAMERA_DIRECTION[3] = { 2.001, 0, 0 },
PI = 3.14159265359, //PI
MAPSIZE = 20.0, //SIZE OF THE CUBE SURROUNDING THE CENTER
SIZESCALE = 100.0; //SCALE THE SIZE OF BOXES
float cameraInformation[3][3], //(CAMERA TRANSLATION FROM ORIGINAL CAMERA LOCATION, CAMERA DIRECTION, CAMERA LOCATION) in (x,y,z)
cursorAngle[2], //POSITION OF CURSOR CONVERTED TO AN ANGLE, in (y,z)
cubeInitialOrigin[3], //ORIGIN OF CUBE WHEN STARTING BUILDING, in (x,y,z)
movementSpeed = 0.0125;
char s[30];
std::string str1 = "FILLINGUPTHESTRING"; //TAKES USERS INPUT OF FILENAME
const char *FILENAME = str1.c_str( );
void window_size( int w, int h ); //TAKE CURRENT SIZE OF WINDOW
void rotate_camera( );
void move_forward( float forwardsOrBackwards );
void move_left( float forwardsOrBackwards );
void move_up( float forwardsOrBackwards );
void keyboard( unsigned char key, int x, int y );
void cuboid ( float OCX, float OCY, float OCZ,
float xsize, float ysize, float zsize,
float TR, float TG, float TB,
float BR, float BG, float BB,
float FR, float FG, float FB,
float BWR, float BWG, float BWB,
float LR, float LG, float LB,
float RR, float RG, float RB ); //PRODUCE CUBOIDS
void display ( ); //RENDERS CUBOIDS, TEXT AND MOLECULES
int main ( int argc, char **argv )
{
ShowCursor( FALSE );
void glutInit( int *argc, char **argv );
glutInitDisplayMode( GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA );
//CREATE WINDOW, SET RESOLUTION AND POSITION
glutInitWindowSize( widthOfMonitor, heightOfMonitor );
glutCreateWindow( "SQUARE" );
glutInitWindowPosition( 0, 0 );
glutFullScreen( );
glColorMaterial ( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE ) ;
glEnable ( GL_COLOR_MATERIAL ) ;
glutReshapeFunc( window_size ); //SET WINDOW CORRECT SIZE
glutKeyboardFunc( keyboard );//DETECT IF KEYBOARD IS PRESSED AND RESPOND
//CONSTANTLY UPDATE DISPLAY AT FRAME rate OF MONITOR (OR LOWER IF CPU/GPU CANNOT PROCESS FAST ENOUGH)
glutDisplayFunc( display );
glutIdleFunc( display );
glEnable( GL_DEPTH_TEST ); //RENDER OBJECTS CLOSEST TO CAMERA INFRONT OF OBJECTS FURTHER AWAY
glutMainLoop( );
}
/*window_size TAKES INPUT OF SIZE OF WINDOW THEN GENERATES THE ORIGINAL CAMERA VIEW*/
void window_size( int widthOfMonitor, int heightOfMonitor ) //TAKE CURRENT SIZE OF WINDOW
{
glMatrixMode( GL_PROJECTION ); //EDIT THE CAMERA SETTINGS
glViewport( 0, 0, widthOfMonitor, heightOfMonitor ); //SET THE RENDERING TO COVER ENTIRE WINDOW
//SET THE PERSPECTIVE
gluPerspective( 90, //FOV
widthOfMonitor / heightOfMonitor, //DISPLAY ASPECT
0.01, //NEAR CLIP
20000.0 ); //FAR CLIP
glMatrixMode( GL_MODELVIEW ); //CHANGE BACK TO EDITING THE WOLRD
gluLookAt( ORIGINAL_CAMERA_LOCATION[0], ORIGINAL_CAMERA_LOCATION[1], ORIGINAL_CAMERA_LOCATION[2], //CAMERA LOCATION
ORIGINAL_CAMERA_LOCATION[0] + ORIGINAL_CAMERA_DIRECTION[0], ORIGINAL_CAMERA_LOCATION[1] + ORIGINAL_CAMERA_LOCATION[1], ORIGINAL_CAMERA_LOCATION[2] + ORIGINAL_CAMERA_LOCATION[2], //LOOK AT
0.0, 1.0, 0.0 ); //VERTICAL DEFINITION
}
/*rotate_camera DETECTS LOCATION OF CURSOR, ADJUSTING THE DIRECTION LOOKED DEPENDING ON WHAT DIRECTION THE MOUSE IS MOVED*/
void rotate_camera( )
{
POINT m1;
GetCursorPos( &m1 );//EXTRACT MOUSE COORDINATES
//DISPLACEMENT FROM CENTRE OF SCREEN IN X&Y
int xmpos = ( m1.x - widthOfMonitor / 2 );
int ympos = ( m1.y - heightOfMonitor / 2 );
//TAKE MOUSE COORDS AND SET WHOLE WINDOW TO BE LENGTH 2PI IN X AND Y
cursorAngle[0] += - ( ( xmpos * 180 / (widthOfMonitor / 2) ) * PI / 180 );
cursorAngle[1] += ( ( ympos * 180 / (heightOfMonitor / 2) ) * PI / 180 );
//DON'T ALLOW ROTATING UP PAST CEILING OR BELOW FLOOR, CAN BE DONE BUT MAKES PERSPECTIVE CONFUSING
if ( cursorAngle[1] > 0 )
cursorAngle[1] = - 1E-5;
else if ( cursorAngle[1] < -PI )
cursorAngle[1] = -( PI - 1E-5 );
//CONVERT FROM SPHERICAL POLARS INTO CARTESIANS
cameraInformation[1][0] = cos( cursorAngle[0] ) * sin( cursorAngle[1] );
cameraInformation[1][1] = sin( cursorAngle[0] ) * sin( cursorAngle[1] );
cameraInformation[1][2] = -cos( cursorAngle[1] );
//KEEP CURSOR CENTERED TO PREVENT SCREEN GETTING STUCK WHEN ROTATING PAST 2PI.
SetCursorPos( widthOfMonitor / 2, heightOfMonitor / 2 );
}
/*MoveForwards TRIGGERS IF W OR S IS PRESSED AND MOVES FORWARD OR BACKWARDS IN THE DIRECTION FACED IF A CUBE IS NOT BEING BUILT, OR MOVES CUBE FORWARD OR BACKWARDS IN THE DIRECTION FACED IF CUBE IS BEING BUILT*/
void move_forward( float forwardsOrBackwards )
{
float changeInX, changeInY, changeInZ, length;
if ( cuboidBuilding == 0 )
{
//GO FORWARD/BACK RELATIVE TO CAMERA VIEW
changeInX = ( forwardsOrBackwards * cameraInformation[1][0] );
changeInY = ( forwardsOrBackwards * cameraInformation[1][1] );
changeInZ = ( forwardsOrBackwards * cameraInformation[1][2] );
//NORMALIZE MOVEMENT
length = sqrt ( pow ( changeInX, 2.0 ) + pow ( changeInY, 2.0 ) + pow ( changeInZ, 2.0 ) );
changeInX = changeInX / length;
changeInY = changeInY / length;
changeInZ = changeInZ / length;
//SET SENSITIVITY AND ADD CHANGE FROM STARTING POSITION TO STARTING POSITION TO GET CURRENT POSITION
cameraInformation[0][0] += changeInX * movementSpeed;
cameraInformation[0][1] += changeInY * movementSpeed;
cameraInformation[0][2] += changeInZ * movementSpeed;
}
}
/*move_left TRIGGERS IF A OR D IS PRESSED AND MOVES LEFT OR RIGHT TO THE DIRECTION FACED IF A CUBE IS NOT BEING BUILT, OR MOVES CUBE LEFT OR RIGHT OF THE DIRECTION FACED IF CUBE IS BEING BUILT*/
void move_left( float forwardsOrBackwards )
{
float changeInX, changeInY, length;
if ( cuboidBuilding == 0 )
{
//GO LEFT/RIGHT RELATIVE TO CAMERA VIEW
changeInX = ( -forwardsOrBackwards * cameraInformation[1][1] );
changeInY = ( forwardsOrBackwards * cameraInformation[1][0] );
//NORMALIZE MOVEMENT
length = sqrt ( pow ( changeInX, 2.0 ) + pow ( changeInY, 2.0 ) );
changeInX = changeInX / length;
changeInY = changeInY / length;
//SET SENSITIVITY AND ADD CHANGE FROM STARTING POSITION TO STARTING POSITION TO GET CURRENT POSITION
cameraInformation[0][0] += changeInX * movementSpeed;
cameraInformation[0][1] += changeInY * movementSpeed;
}
}
/*move_up TRIGGERS IF Q OR E IS PRESSED AND MOVES VERTICALLY UP OR DOWN IF A CUBE IS NOT BEING BUILT, OR MOVES CUBE VERTICALLY UP OR DOWN IF CUBE IS BEING BUILT*/
void move_up( float forwardsOrBackwards )
{
//MOVEMENT AND MAKING CUBE AS THE DIRECTION MOVED IS ALWAYS PARRALEL TO Z COORDS, SO NO CONVERSION FROM CAMERA TO BOX IS REQUIRED
float changeInZ, length;
//GO UP/DOWN RELATIVE TO CAMERA VIEW
changeInZ = ( forwardsOrBackwards );
//NORMALIZE MOVEMENT
length = sqrt( pow ( changeInZ, 2.0 ) );
changeInZ = changeInZ / length;
//SET SENSITIVITY
if ( cuboidBuilding == 0 )
cameraInformation[0][2] += changeInZ * movementSpeed;
//ADD CHANGE FROM STARTING POSITION TO STARTING POSITION TO GET CURRENT POSITION
}
/*keyboard TRIGGERS IF A KEY ON THE KEYBOARD IS PRESSED, THEN PASSES TO A FUNCTION THAT PROCESSES THE KEY PRESSED, ALSO UPDATES THE LOCATION OF CAMERA IF MOVEMENT KEYS ARE PRESSED */
void keyboard( unsigned char key, int x, int y )
{
int forwardsOrBackwards; //FORWARD OR BACKWORDS.
//PREVENT A POTENTIAL DIVIDE BY 0 ERROR BY SETTING 0 DIRECTIONS TO VERY SMALL DIRECTIONS.
for ( int i = 0; i <= 2; i++ )
{
if ( cameraInformation[1][i] > -1E-5 && cameraInformation[1][i] < 1E-5 )
cameraInformation[1][i] = 1E-4;
}
switch ( key )
{
case 122: case 90: //z
if ( movementSpeed < 0.5 )
movementSpeed = 1.0;
else
movementSpeed = 0.025;
break;
case 119: case 52: forwardsOrBackwards = 1; move_forward ( forwardsOrBackwards ); break; //w
case 115: case 83: forwardsOrBackwards = -1;move_forward ( forwardsOrBackwards ); break; //s
case 97 : case 65: forwardsOrBackwards = 1; move_left ( forwardsOrBackwards ); break; //a
case 100: case 68: forwardsOrBackwards = -1;move_left ( forwardsOrBackwards ); break; //d
case 113: case 81: forwardsOrBackwards = -1;move_up ( forwardsOrBackwards ); break; //q
case 101: case 69: forwardsOrBackwards = 1; move_up ( forwardsOrBackwards ); break; //e
case 27 : exit ( 0 ); //esc CLOSE PROGRAM
}
if ( cuboidBuilding == 0 ) //IF NOT BUILDING A CUBE, MOVE CAMERA COORDS BY THE AMOUNT THEY HAVE CHANGED
{
for ( int i = 0; i <=2; i++)
{
cameraInformation[2][i] = ORIGINAL_CAMERA_LOCATION[i] + cameraInformation[0][i];
}
}
}
/*cuboid TAKES INPUTS OF CENTER OF CUBE, SIZE OF CUBE AND COLOURS OF EACH FACE THEN PRODUCES A CUBE BY SPLITING EACH FACE UP INTO TWO TRIANGLES*/
void cuboid ( float OCX, float OCY, float OCZ,
float xsize, float ysize, float zsize,
float TR, float TG, float TB,
float BR, float BG, float BB,
float FR, float FG, float FB,
float BWR, float BWG, float BWB,
float LR, float LG, float LB,
float RR, float RG, float RB )
{
glBegin( GL_TRIANGLES );
//MAKE TRIANGLES IN SHAPE OF A CUBE BY SPECIFYING VERTICES OF TRIANGLES
glColor3f ( TR, TG, TB ); //TOP
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ + zsize );
glColor3f ( BR, BG, BB ); //BOTTOM
glVertex3f( OCX - xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ - zsize );
glColor3f ( FR, FG, FB ); //FORWARDS
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ - zsize );
glColor3f ( BWR, BWG, BWB ); //BACKWARDS
glVertex3f( OCX - xsize, OCY + ysize, OCZ + zsize);
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ - zsize );
glColor3f ( LR, LG, LB ); //LEFT
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ + zsize );
glColor3f ( RR, RG, RB ); //RIGHT
glVertex3f( OCX + xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ + zsize );
glEnd( );
}
/*place_cuboid TRIGGERS IF LEFT MOUSE BUTTON IS PLACED, CAUSES A TEMPORARY CUBE TO APPEAR AT THE CURSOR LOCATION, THEN WHEN LEFT MOUSE BUTTON IS RELEASED IT SAVES THE CENTER,SIZE AND COLOUR OF THIS TEMPORARY CUBE INTO THE PERMAMENT ARRAYS OF CUBS*/
/*display TAKES THE ARRAYS OF CUBE AND MOLECULE LOCATIONS, SIZE AND COLOURS THEN RENDERS AND CHECKS IF MOLECULES ARE COLLIDING WITH A CUBE*/
void display ( )
{
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
//SET EDGES OF THE MAP
cuboid ( 0.0, 0.0, 0.0,
MAPSIZE, MAPSIZE, MAPSIZE,
0.0, 0.0, 1.0,
0.0, 1.0, 0.0,
0.0, 1.0, 0.0,
0.0, 1.0, 0.0,
0.0, 1.0, 0.0,
0.0, 1.0, 0.0 );
glColor3d( 1.0, 0.0, 0.0 );
glPushMatrix( );
glLoadIdentity( );
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glMatrixMode(GL_MODELVIEW);
rotate_camera( ); //ROTATE CAMERA WITH MOUSE
//MOVE CAMERA
gluLookAt( cameraInformation[2][0], cameraInformation[2][1], cameraInformation[2][2], //Camera location
cameraInformation[2][0] + cameraInformation[1][0], cameraInformation[2][1] + cameraInformation[1][1], cameraInformation[2][2] + cameraInformation[1][2], //LOOK AT
0.0, 0.0, 1.0 ); //VERTICAL
glutSwapBuffers();
}
- 在调用
glutInit() 之前不要使用 glutGet()
- 初始化你的变量
- 使用 C++ 风格
#includes
- 在显示回调中设置矩阵，有助于防止使用错误
- 不需要使用 Windows 到 track/hide 光标，(Free)GLUT 有相应的功能
- 用合理的方式换行
- timerfunc 或 vsync 在 battery/CPU 风扇上比闲置回调更友好
总计：
#include <GL/freeglut.h>
#include <cmath>
int cuboidBuilding = 0;//IS A CUBE CURRENTLY BEING BUILT? 0 FOR NO, 1 FOR YES.
const float ORIGINAL_CAMERA_LOCATION[3] = { 0, 0, 0 }, //ORIGINAL CAMERA LOCATION
ORIGINAL_CAMERA_DIRECTION[3] = { 2.001, 0, 0 },
PI = 3.14159265359, //PI
MAPSIZE = 20.0, //SIZE OF THE CUBE SURROUNDING THE CENTER
SIZESCALE = 100.0; //SCALE THE SIZE OF BOXES
float cameraInformation[3][3], //(CAMERA TRANSLATION FROM ORIGINAL CAMERA LOCATION, CAMERA DIRECTION, CAMERA LOCATION) in (x,y,z)
cursorAngle[2], //POSITION OF CURSOR CONVERTED TO AN ANGLE, in (y,z)
cubeInitialOrigin[3], //ORIGIN OF CUBE WHEN STARTING BUILDING, in (x,y,z)
movementSpeed = 0.0125;
// DETECTS LOCATION OF CURSOR, ADJUSTING THE
// DIRECTION LOOKED DEPENDING ON WHAT DIRECTION THE MOUSE IS MOVED
bool warped = false;
void passiveMotion( int x, int y )
{
if( warped )
{
// break warp loop
warped = false;
return;
}
int widthOfMonitor = glutGet( GLUT_WINDOW_WIDTH );
int heightOfMonitor = glutGet( GLUT_WINDOW_HEIGHT );
//DISPLACEMENT FROM CENTRE OF SCREEN IN X&Y
int xmpos = ( x - widthOfMonitor / 2 );
int ympos = ( y - heightOfMonitor / 2 );
//TAKE MOUSE COORDS AND SET WHOLE WINDOW TO BE LENGTH 2PI IN X AND Y
cursorAngle[0] += - ( ( xmpos * 180 / (widthOfMonitor / 2) ) * PI / 180 );
cursorAngle[1] += ( ( ympos * 180 / (heightOfMonitor / 2) ) * PI / 180 );
//DON'T ALLOW ROTATING UP PAST CEILING OR BELOW FLOOR, CAN BE DONE BUT MAKES PERSPECTIVE CONFUSING
if ( cursorAngle[1] > 0 )
cursorAngle[1] = - 1E-5;
else if ( cursorAngle[1] < -PI )
cursorAngle[1] = -( PI - 1E-5 );
//CONVERT FROM SPHERICAL POLARS INTO CARTESIANS
cameraInformation[1][0] = cos( cursorAngle[0] ) * sin( cursorAngle[1] );
cameraInformation[1][1] = sin( cursorAngle[0] ) * sin( cursorAngle[1] );
cameraInformation[1][2] = -cos( cursorAngle[1] );
//KEEP CURSOR CENTERED TO PREVENT SCREEN GETTING STUCK WHEN ROTATING PAST 2PI.
warped = true;
glutWarpPointer( widthOfMonitor / 2, heightOfMonitor / 2 );
}
// MoveForwards TRIGGERS IF W OR S IS PRESSED AND MOVES FORWARD OR BACKWARDS
// IN THE DIRECTION FACED IF A CUBE IS NOT BEING BUILT, OR MOVES CUBE FORWARD
// OR BACKWARDS IN THE DIRECTION FACED IF CUBE IS BEING BUILT
void move_forward( float forwardsOrBackwards )
{
float changeInX, changeInY, changeInZ, length;
if ( cuboidBuilding == 0 )
{
//GO FORWARD/BACK RELATIVE TO CAMERA VIEW
changeInX = ( forwardsOrBackwards * cameraInformation[1][0] );
changeInY = ( forwardsOrBackwards * cameraInformation[1][1] );
changeInZ = ( forwardsOrBackwards * cameraInformation[1][2] );
//NORMALIZE MOVEMENT
length = sqrt ( pow ( changeInX, 2.0 ) + pow ( changeInY, 2.0 ) + pow ( changeInZ, 2.0 ) );
changeInX = changeInX / length;
changeInY = changeInY / length;
changeInZ = changeInZ / length;
//SET SENSITIVITY AND ADD CHANGE FROM STARTING POSITION TO STARTING POSITION TO GET CURRENT POSITION
cameraInformation[0][0] += changeInX * movementSpeed;
cameraInformation[0][1] += changeInY * movementSpeed;
cameraInformation[0][2] += changeInZ * movementSpeed;
}
}
// move_left TRIGGERS IF A OR D IS PRESSED AND MOVES LEFT OR RIGHT TO THE
// DIRECTION FACED IF A CUBE IS NOT BEING BUILT, OR MOVES CUBE
// LEFT OR RIGHT OF THE DIRECTION FACED IF CUBE IS BEING BUILT
void move_left( float forwardsOrBackwards )
{
float changeInX, changeInY, length;
if ( cuboidBuilding == 0 )
{
//GO LEFT/RIGHT RELATIVE TO CAMERA VIEW
changeInX = ( -forwardsOrBackwards * cameraInformation[1][1] );
changeInY = ( forwardsOrBackwards * cameraInformation[1][0] );
//NORMALIZE MOVEMENT
length = sqrt ( pow ( changeInX, 2.0 ) + pow ( changeInY, 2.0 ) );
changeInX = changeInX / length;
changeInY = changeInY / length;
//SET SENSITIVITY AND ADD CHANGE FROM STARTING POSITION TO STARTING POSITION TO GET CURRENT POSITION
cameraInformation[0][0] += changeInX * movementSpeed;
cameraInformation[0][1] += changeInY * movementSpeed;
}
}
// move_up TRIGGERS IF Q OR E IS PRESSED AND MOVES VERTICALLY UP OR DOWN
// IF A CUBE IS NOT BEING BUILT, OR MOVES CUBE VERTICALLY UP OR DOWN IF CUBE IS BEING BUILT
void move_up( float forwardsOrBackwards )
{
//MOVEMENT AND MAKING CUBE AS THE DIRECTION MOVED IS ALWAYS PARRALEL TO Z COORDS, SO NO CONVERSION FROM CAMERA TO BOX IS REQUIRED
float changeInZ, length;
//GO UP/DOWN RELATIVE TO CAMERA VIEW
changeInZ = ( forwardsOrBackwards );
//NORMALIZE MOVEMENT
length = sqrt( pow ( changeInZ, 2.0 ) );
changeInZ = changeInZ / length;
//SET SENSITIVITY
if ( cuboidBuilding == 0 )
cameraInformation[0][2] += changeInZ * movementSpeed;
//ADD CHANGE FROM STARTING POSITION TO STARTING POSITION TO GET CURRENT POSITION
}
// keyboard TRIGGERS IF A KEY ON THE KEYBOARD IS PRESSED,
// THEN PASSES TO A FUNCTION THAT PROCESSES THE KEY PRESSED,
// ALSO UPDATES THE LOCATION OF CAMERA IF MOVEMENT KEYS ARE PRESSED
void keyboard( unsigned char key, int x, int y )
{
int forwardsOrBackwards; //FORWARD OR BACKWORDS.
//PREVENT A POTENTIAL DIVIDE BY 0 ERROR BY SETTING 0 DIRECTIONS TO VERY SMALL DIRECTIONS.
for ( int i = 0; i <= 2; i++ )
{
if ( cameraInformation[1][i] > -1E-5 && cameraInformation[1][i] < 1E-5 )
cameraInformation[1][i] = 1E-4;
}
switch ( key )
{
case 122: case 90: //z
if ( movementSpeed < 0.5 )
movementSpeed = 1.0;
else
movementSpeed = 0.025;
break;
case 119: case 52: forwardsOrBackwards = 1; move_forward ( forwardsOrBackwards ); break; //w
case 115: case 83: forwardsOrBackwards = -1;move_forward ( forwardsOrBackwards ); break; //s
case 97 : case 65: forwardsOrBackwards = 1; move_left ( forwardsOrBackwards ); break; //a
case 100: case 68: forwardsOrBackwards = -1;move_left ( forwardsOrBackwards ); break; //d
case 113: case 81: forwardsOrBackwards = -1;move_up ( forwardsOrBackwards ); break; //q
case 101: case 69: forwardsOrBackwards = 1; move_up ( forwardsOrBackwards ); break; //e
case 27 : exit ( 0 ); //esc CLOSE PROGRAM
}
if ( cuboidBuilding == 0 ) //IF NOT BUILDING A CUBE, MOVE CAMERA COORDS BY THE AMOUNT THEY HAVE CHANGED
{
for ( int i = 0; i <=2; i++)
{
cameraInformation[2][i] = ORIGINAL_CAMERA_LOCATION[i] + cameraInformation[0][i];
}
}
}
// cuboid TAKES INPUTS OF CENTER OF CUBE, SIZE OF CUBE AND COLOURS OF EACH FACE
// THEN PRODUCES A CUBE BY SPLITING EACH FACE UP INTO TWO TRIANGLES
void cuboid
(
float OCX, float OCY, float OCZ,
float xsize, float ysize, float zsize,
float TR, float TG, float TB,
float BR, float BG, float BB,
float FR, float FG, float FB,
float BWR, float BWG, float BWB,
float LR, float LG, float LB,
float RR, float RG, float RB
)
{
glBegin( GL_TRIANGLES );
//MAKE TRIANGLES IN SHAPE OF A CUBE BY SPECIFYING VERTICES OF TRIANGLES
glColor3f ( TR, TG, TB ); //TOP
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ + zsize );
glColor3f ( BR, BG, BB ); //BOTTOM
glVertex3f( OCX - xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ - zsize );
glColor3f ( FR, FG, FB ); //FORWARDS
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ - zsize );
glColor3f ( BWR, BWG, BWB ); //BACKWARDS
glVertex3f( OCX - xsize, OCY + ysize, OCZ + zsize);
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ - zsize );
glColor3f ( LR, LG, LB ); //LEFT
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ + zsize );
glColor3f ( RR, RG, RB ); //RIGHT
glVertex3f( OCX + xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ + zsize );
glEnd( );
}
// display TAKES THE ARRAYS OF CUBE AND MOLECULE LOCATIONS, SIZE AND
// COLOURS THEN RENDERS AND CHECKS IF MOLECULES ARE COLLIDING WITH A CUBE
void display ( )
{
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
//SET THE PERSPECTIVE
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
int widthOfMonitor = glutGet( GLUT_WINDOW_WIDTH );
int heightOfMonitor = glutGet( GLUT_WINDOW_HEIGHT );
gluPerspective( 90, //FOV
widthOfMonitor / heightOfMonitor, //DISPLAY ASPECT
0.01, //NEAR CLIP
20000.0 ); //FAR CLIP
//MOVE CAMERA
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt
(
cameraInformation[2][0], cameraInformation[2][1], cameraInformation[2][2], //Camera location
cameraInformation[2][0] + cameraInformation[1][0],
cameraInformation[2][1] + cameraInformation[1][1],
cameraInformation[2][2] + cameraInformation[1][2], //LOOK AT
0.0, 0.0, 1.0
); //VERTICAL
glColorMaterial ( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE ) ;
glEnable ( GL_COLOR_MATERIAL ) ;
glEnable( GL_DEPTH_TEST ); //RENDER OBJECTS CLOSEST TO CAMERA INFRONT OF OBJECTS FURTHER AWAY
//SET EDGES OF THE MAP
glColor3d( 1.0, 0.0, 0.0 );
cuboid
(
0.0, 0.0, 0.0,
MAPSIZE, MAPSIZE, MAPSIZE,
0.0, 0.0, 1.0,
0.0, 1.0, 0.0,
0.0, 1.0, 0.0,
0.0, 1.0, 0.0,
0.0, 1.0, 0.0,
0.0, 1.0, 0.0
);
glutSwapBuffers();
}
void timer( int value )
{
glutPostRedisplay();
glutTimerFunc( 16, timer, 0 );
}
int main ( int argc, char **argv )
{
glutInit( &argc, argv );
glutInitDisplayMode( GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA );
glutInitWindowSize( 600, 600 );
glutInitWindowPosition( 0, 0 );
glutCreateWindow( "SQUARE" );
glutKeyboardFunc( keyboard );
glutDisplayFunc( display );
glutPassiveMotionFunc( passiveMotion );
glutTimerFunc( 0, timer, 0 );
glutSetCursor( GLUT_CURSOR_NONE );
glutMainLoop( );
}
glutPostRedisplay 是这里的主要内容。您甚至可以 post 它来自内部显示功能。没有它，它将无法工作。
我有一个我在 6 个多月前编写的程序，它使用了 GLUT 库。 6 个月前我写的时候它运行得非常好。从那以后我就没有使用过它，也没有以任何方式编辑过代码。
该程序有一些立方体以一些随机速度四处漂浮，它们会从它们所在环境的墙壁上反弹。可以使用箭头键和 panned/tilted 使用鼠标移动摄像机。可以通过单击向环境中添加更多的墙，然后可以使用箭头键调整这些墙的位置。
然而，尽管这在 6 个月前是有效的，但现在摄像机仅 pans/tilts 在程序的前几帧使用鼠标，使用箭头键移动摄像机也是如此。但是程序并没有冻结，我仍然可以看到立方体漂浮在周围，可以添加和调整位置的墙仍然可以移动。
是否有任何常见原因导致以前工作的 GLUT 程序只能在前几帧正常运行？
#include <iostream>
#include <GL/glut.h>
#include <Windows.h> //FOR CURSOR
#include <tgmath.h> //FOR MATHS
#include <fstream>
#include <string>
#include <time.h> //FOR THE TIME FOR RANDOM GENERATOR SEED
const int MAXMOLECULES = 1000000, MAXCUBOIDS = 10000, NUMBER_OF_PRESSURE_SENSORS = 3, MAX_RECORDING_TIME = 1000000;
int widthOfMonitor = glutGet( GLUT_SCREEN_WIDTH ), heightOfMonitor = glutGet( GLUT_SCREEN_HEIGHT ),
cuboidBuilding = 0;//IS A CUBE CURRENTLY BEING BUILT? 0 FOR NO, 1 FOR YES.
const float ORIGINAL_CAMERA_LOCATION[3] = { 0, 0, 0 }, //ORIGINAL CAMERA LOCATION
ORIGINAL_CAMERA_DIRECTION[3] = { 2.001, 0, 0 },
PI = 3.14159265359, //PI
MAPSIZE = 20.0, //SIZE OF THE CUBE SURROUNDING THE CENTER
SIZESCALE = 100.0; //SCALE THE SIZE OF BOXES
float cameraInformation[3][3], //(CAMERA TRANSLATION FROM ORIGINAL CAMERA LOCATION, CAMERA DIRECTION, CAMERA LOCATION) in (x,y,z)
cursorAngle[2], //POSITION OF CURSOR CONVERTED TO AN ANGLE, in (y,z)
cubeInitialOrigin[3], //ORIGIN OF CUBE WHEN STARTING BUILDING, in (x,y,z)
movementSpeed = 0.0125;
char s[30];
std::string str1 = "FILLINGUPTHESTRING"; //TAKES USERS INPUT OF FILENAME
const char *FILENAME = str1.c_str( );
void window_size( int w, int h ); //TAKE CURRENT SIZE OF WINDOW
void rotate_camera( );
void move_forward( float forwardsOrBackwards );
void move_left( float forwardsOrBackwards );
void move_up( float forwardsOrBackwards );
void keyboard( unsigned char key, int x, int y );
void cuboid ( float OCX, float OCY, float OCZ,
float xsize, float ysize, float zsize,
float TR, float TG, float TB,
float BR, float BG, float BB,
float FR, float FG, float FB,
float BWR, float BWG, float BWB,
float LR, float LG, float LB,
float RR, float RG, float RB ); //PRODUCE CUBOIDS
void display ( ); //RENDERS CUBOIDS, TEXT AND MOLECULES
int main ( int argc, char **argv )
{
ShowCursor( FALSE );
void glutInit( int *argc, char **argv );
glutInitDisplayMode( GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA );
//CREATE WINDOW, SET RESOLUTION AND POSITION
glutInitWindowSize( widthOfMonitor, heightOfMonitor );
glutCreateWindow( "SQUARE" );
glutInitWindowPosition( 0, 0 );
glutFullScreen( );
glColorMaterial ( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE ) ;
glEnable ( GL_COLOR_MATERIAL ) ;
glutReshapeFunc( window_size ); //SET WINDOW CORRECT SIZE
glutKeyboardFunc( keyboard );//DETECT IF KEYBOARD IS PRESSED AND RESPOND
//CONSTANTLY UPDATE DISPLAY AT FRAME rate OF MONITOR (OR LOWER IF CPU/GPU CANNOT PROCESS FAST ENOUGH)
glutDisplayFunc( display );
glutIdleFunc( display );
glEnable( GL_DEPTH_TEST ); //RENDER OBJECTS CLOSEST TO CAMERA INFRONT OF OBJECTS FURTHER AWAY
glutMainLoop( );
}
/*window_size TAKES INPUT OF SIZE OF WINDOW THEN GENERATES THE ORIGINAL CAMERA VIEW*/
void window_size( int widthOfMonitor, int heightOfMonitor ) //TAKE CURRENT SIZE OF WINDOW
{
glMatrixMode( GL_PROJECTION ); //EDIT THE CAMERA SETTINGS
glViewport( 0, 0, widthOfMonitor, heightOfMonitor ); //SET THE RENDERING TO COVER ENTIRE WINDOW
//SET THE PERSPECTIVE
gluPerspective( 90, //FOV
widthOfMonitor / heightOfMonitor, //DISPLAY ASPECT
0.01, //NEAR CLIP
20000.0 ); //FAR CLIP
glMatrixMode( GL_MODELVIEW ); //CHANGE BACK TO EDITING THE WOLRD
gluLookAt( ORIGINAL_CAMERA_LOCATION[0], ORIGINAL_CAMERA_LOCATION[1], ORIGINAL_CAMERA_LOCATION[2], //CAMERA LOCATION
ORIGINAL_CAMERA_LOCATION[0] + ORIGINAL_CAMERA_DIRECTION[0], ORIGINAL_CAMERA_LOCATION[1] + ORIGINAL_CAMERA_LOCATION[1], ORIGINAL_CAMERA_LOCATION[2] + ORIGINAL_CAMERA_LOCATION[2], //LOOK AT
0.0, 1.0, 0.0 ); //VERTICAL DEFINITION
}
/*rotate_camera DETECTS LOCATION OF CURSOR, ADJUSTING THE DIRECTION LOOKED DEPENDING ON WHAT DIRECTION THE MOUSE IS MOVED*/
void rotate_camera( )
{
POINT m1;
GetCursorPos( &m1 );//EXTRACT MOUSE COORDINATES
//DISPLACEMENT FROM CENTRE OF SCREEN IN X&Y
int xmpos = ( m1.x - widthOfMonitor / 2 );
int ympos = ( m1.y - heightOfMonitor / 2 );
//TAKE MOUSE COORDS AND SET WHOLE WINDOW TO BE LENGTH 2PI IN X AND Y
cursorAngle[0] += - ( ( xmpos * 180 / (widthOfMonitor / 2) ) * PI / 180 );
cursorAngle[1] += ( ( ympos * 180 / (heightOfMonitor / 2) ) * PI / 180 );
//DON'T ALLOW ROTATING UP PAST CEILING OR BELOW FLOOR, CAN BE DONE BUT MAKES PERSPECTIVE CONFUSING
if ( cursorAngle[1] > 0 )
cursorAngle[1] = - 1E-5;
else if ( cursorAngle[1] < -PI )
cursorAngle[1] = -( PI - 1E-5 );
//CONVERT FROM SPHERICAL POLARS INTO CARTESIANS
cameraInformation[1][0] = cos( cursorAngle[0] ) * sin( cursorAngle[1] );
cameraInformation[1][1] = sin( cursorAngle[0] ) * sin( cursorAngle[1] );
cameraInformation[1][2] = -cos( cursorAngle[1] );
//KEEP CURSOR CENTERED TO PREVENT SCREEN GETTING STUCK WHEN ROTATING PAST 2PI.
SetCursorPos( widthOfMonitor / 2, heightOfMonitor / 2 );
}
/*MoveForwards TRIGGERS IF W OR S IS PRESSED AND MOVES FORWARD OR BACKWARDS IN THE DIRECTION FACED IF A CUBE IS NOT BEING BUILT, OR MOVES CUBE FORWARD OR BACKWARDS IN THE DIRECTION FACED IF CUBE IS BEING BUILT*/
void move_forward( float forwardsOrBackwards )
{
float changeInX, changeInY, changeInZ, length;
if ( cuboidBuilding == 0 )
{
//GO FORWARD/BACK RELATIVE TO CAMERA VIEW
changeInX = ( forwardsOrBackwards * cameraInformation[1][0] );
changeInY = ( forwardsOrBackwards * cameraInformation[1][1] );
changeInZ = ( forwardsOrBackwards * cameraInformation[1][2] );
//NORMALIZE MOVEMENT
length = sqrt ( pow ( changeInX, 2.0 ) + pow ( changeInY, 2.0 ) + pow ( changeInZ, 2.0 ) );
changeInX = changeInX / length;
changeInY = changeInY / length;
changeInZ = changeInZ / length;
//SET SENSITIVITY AND ADD CHANGE FROM STARTING POSITION TO STARTING POSITION TO GET CURRENT POSITION
cameraInformation[0][0] += changeInX * movementSpeed;
cameraInformation[0][1] += changeInY * movementSpeed;
cameraInformation[0][2] += changeInZ * movementSpeed;
}
}
/*move_left TRIGGERS IF A OR D IS PRESSED AND MOVES LEFT OR RIGHT TO THE DIRECTION FACED IF A CUBE IS NOT BEING BUILT, OR MOVES CUBE LEFT OR RIGHT OF THE DIRECTION FACED IF CUBE IS BEING BUILT*/
void move_left( float forwardsOrBackwards )
{
float changeInX, changeInY, length;
if ( cuboidBuilding == 0 )
{
//GO LEFT/RIGHT RELATIVE TO CAMERA VIEW
changeInX = ( -forwardsOrBackwards * cameraInformation[1][1] );
changeInY = ( forwardsOrBackwards * cameraInformation[1][0] );
//NORMALIZE MOVEMENT
length = sqrt ( pow ( changeInX, 2.0 ) + pow ( changeInY, 2.0 ) );
changeInX = changeInX / length;
changeInY = changeInY / length;
//SET SENSITIVITY AND ADD CHANGE FROM STARTING POSITION TO STARTING POSITION TO GET CURRENT POSITION
cameraInformation[0][0] += changeInX * movementSpeed;
cameraInformation[0][1] += changeInY * movementSpeed;
}
}
/*move_up TRIGGERS IF Q OR E IS PRESSED AND MOVES VERTICALLY UP OR DOWN IF A CUBE IS NOT BEING BUILT, OR MOVES CUBE VERTICALLY UP OR DOWN IF CUBE IS BEING BUILT*/
void move_up( float forwardsOrBackwards )
{
//MOVEMENT AND MAKING CUBE AS THE DIRECTION MOVED IS ALWAYS PARRALEL TO Z COORDS, SO NO CONVERSION FROM CAMERA TO BOX IS REQUIRED
float changeInZ, length;
//GO UP/DOWN RELATIVE TO CAMERA VIEW
changeInZ = ( forwardsOrBackwards );
//NORMALIZE MOVEMENT
length = sqrt( pow ( changeInZ, 2.0 ) );
changeInZ = changeInZ / length;
//SET SENSITIVITY
if ( cuboidBuilding == 0 )
cameraInformation[0][2] += changeInZ * movementSpeed;
//ADD CHANGE FROM STARTING POSITION TO STARTING POSITION TO GET CURRENT POSITION
}
/*keyboard TRIGGERS IF A KEY ON THE KEYBOARD IS PRESSED, THEN PASSES TO A FUNCTION THAT PROCESSES THE KEY PRESSED, ALSO UPDATES THE LOCATION OF CAMERA IF MOVEMENT KEYS ARE PRESSED */
void keyboard( unsigned char key, int x, int y )
{
int forwardsOrBackwards; //FORWARD OR BACKWORDS.
//PREVENT A POTENTIAL DIVIDE BY 0 ERROR BY SETTING 0 DIRECTIONS TO VERY SMALL DIRECTIONS.
for ( int i = 0; i <= 2; i++ )
{
if ( cameraInformation[1][i] > -1E-5 && cameraInformation[1][i] < 1E-5 )
cameraInformation[1][i] = 1E-4;
}
switch ( key )
{
case 122: case 90: //z
if ( movementSpeed < 0.5 )
movementSpeed = 1.0;
else
movementSpeed = 0.025;
break;
case 119: case 52: forwardsOrBackwards = 1; move_forward ( forwardsOrBackwards ); break; //w
case 115: case 83: forwardsOrBackwards = -1;move_forward ( forwardsOrBackwards ); break; //s
case 97 : case 65: forwardsOrBackwards = 1; move_left ( forwardsOrBackwards ); break; //a
case 100: case 68: forwardsOrBackwards = -1;move_left ( forwardsOrBackwards ); break; //d
case 113: case 81: forwardsOrBackwards = -1;move_up ( forwardsOrBackwards ); break; //q
case 101: case 69: forwardsOrBackwards = 1; move_up ( forwardsOrBackwards ); break; //e
case 27 : exit ( 0 ); //esc CLOSE PROGRAM
}
if ( cuboidBuilding == 0 ) //IF NOT BUILDING A CUBE, MOVE CAMERA COORDS BY THE AMOUNT THEY HAVE CHANGED
{
for ( int i = 0; i <=2; i++)
{
cameraInformation[2][i] = ORIGINAL_CAMERA_LOCATION[i] + cameraInformation[0][i];
}
}
}
/*cuboid TAKES INPUTS OF CENTER OF CUBE, SIZE OF CUBE AND COLOURS OF EACH FACE THEN PRODUCES A CUBE BY SPLITING EACH FACE UP INTO TWO TRIANGLES*/
void cuboid ( float OCX, float OCY, float OCZ,
float xsize, float ysize, float zsize,
float TR, float TG, float TB,
float BR, float BG, float BB,
float FR, float FG, float FB,
float BWR, float BWG, float BWB,
float LR, float LG, float LB,
float RR, float RG, float RB )
{
glBegin( GL_TRIANGLES );
//MAKE TRIANGLES IN SHAPE OF A CUBE BY SPECIFYING VERTICES OF TRIANGLES
glColor3f ( TR, TG, TB ); //TOP
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ + zsize );
glColor3f ( BR, BG, BB ); //BOTTOM
glVertex3f( OCX - xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ - zsize );
glColor3f ( FR, FG, FB ); //FORWARDS
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ - zsize );
glColor3f ( BWR, BWG, BWB ); //BACKWARDS
glVertex3f( OCX - xsize, OCY + ysize, OCZ + zsize);
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ - zsize );
glColor3f ( LR, LG, LB ); //LEFT
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ + zsize );
glColor3f ( RR, RG, RB ); //RIGHT
glVertex3f( OCX + xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ + zsize );
glEnd( );
}
/*place_cuboid TRIGGERS IF LEFT MOUSE BUTTON IS PLACED, CAUSES A TEMPORARY CUBE TO APPEAR AT THE CURSOR LOCATION, THEN WHEN LEFT MOUSE BUTTON IS RELEASED IT SAVES THE CENTER,SIZE AND COLOUR OF THIS TEMPORARY CUBE INTO THE PERMAMENT ARRAYS OF CUBS*/
/*display TAKES THE ARRAYS OF CUBE AND MOLECULE LOCATIONS, SIZE AND COLOURS THEN RENDERS AND CHECKS IF MOLECULES ARE COLLIDING WITH A CUBE*/
void display ( )
{
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
//SET EDGES OF THE MAP
cuboid ( 0.0, 0.0, 0.0,
MAPSIZE, MAPSIZE, MAPSIZE,
0.0, 0.0, 1.0,
0.0, 1.0, 0.0,
0.0, 1.0, 0.0,
0.0, 1.0, 0.0,
0.0, 1.0, 0.0,
0.0, 1.0, 0.0 );
glColor3d( 1.0, 0.0, 0.0 );
glPushMatrix( );
glLoadIdentity( );
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glMatrixMode(GL_MODELVIEW);
rotate_camera( ); //ROTATE CAMERA WITH MOUSE
//MOVE CAMERA
gluLookAt( cameraInformation[2][0], cameraInformation[2][1], cameraInformation[2][2], //Camera location
cameraInformation[2][0] + cameraInformation[1][0], cameraInformation[2][1] + cameraInformation[1][1], cameraInformation[2][2] + cameraInformation[1][2], //LOOK AT
0.0, 0.0, 1.0 ); //VERTICAL
glutSwapBuffers();
}
- 在调用
glutInit() 之前不要使用 - 初始化你的变量
- 使用 C++ 风格
#includes - 在显示回调中设置矩阵，有助于防止使用错误
- 不需要使用 Windows 到 track/hide 光标，(Free)GLUT 有相应的功能
- 用合理的方式换行
- timerfunc 或 vsync 在 battery/CPU 风扇上比闲置回调更友好
glutGet()
总计：
#include <GL/freeglut.h>
#include <cmath>
int cuboidBuilding = 0;//IS A CUBE CURRENTLY BEING BUILT? 0 FOR NO, 1 FOR YES.
const float ORIGINAL_CAMERA_LOCATION[3] = { 0, 0, 0 }, //ORIGINAL CAMERA LOCATION
ORIGINAL_CAMERA_DIRECTION[3] = { 2.001, 0, 0 },
PI = 3.14159265359, //PI
MAPSIZE = 20.0, //SIZE OF THE CUBE SURROUNDING THE CENTER
SIZESCALE = 100.0; //SCALE THE SIZE OF BOXES
float cameraInformation[3][3], //(CAMERA TRANSLATION FROM ORIGINAL CAMERA LOCATION, CAMERA DIRECTION, CAMERA LOCATION) in (x,y,z)
cursorAngle[2], //POSITION OF CURSOR CONVERTED TO AN ANGLE, in (y,z)
cubeInitialOrigin[3], //ORIGIN OF CUBE WHEN STARTING BUILDING, in (x,y,z)
movementSpeed = 0.0125;
// DETECTS LOCATION OF CURSOR, ADJUSTING THE
// DIRECTION LOOKED DEPENDING ON WHAT DIRECTION THE MOUSE IS MOVED
bool warped = false;
void passiveMotion( int x, int y )
{
if( warped )
{
// break warp loop
warped = false;
return;
}
int widthOfMonitor = glutGet( GLUT_WINDOW_WIDTH );
int heightOfMonitor = glutGet( GLUT_WINDOW_HEIGHT );
//DISPLACEMENT FROM CENTRE OF SCREEN IN X&Y
int xmpos = ( x - widthOfMonitor / 2 );
int ympos = ( y - heightOfMonitor / 2 );
//TAKE MOUSE COORDS AND SET WHOLE WINDOW TO BE LENGTH 2PI IN X AND Y
cursorAngle[0] += - ( ( xmpos * 180 / (widthOfMonitor / 2) ) * PI / 180 );
cursorAngle[1] += ( ( ympos * 180 / (heightOfMonitor / 2) ) * PI / 180 );
//DON'T ALLOW ROTATING UP PAST CEILING OR BELOW FLOOR, CAN BE DONE BUT MAKES PERSPECTIVE CONFUSING
if ( cursorAngle[1] > 0 )
cursorAngle[1] = - 1E-5;
else if ( cursorAngle[1] < -PI )
cursorAngle[1] = -( PI - 1E-5 );
//CONVERT FROM SPHERICAL POLARS INTO CARTESIANS
cameraInformation[1][0] = cos( cursorAngle[0] ) * sin( cursorAngle[1] );
cameraInformation[1][1] = sin( cursorAngle[0] ) * sin( cursorAngle[1] );
cameraInformation[1][2] = -cos( cursorAngle[1] );
//KEEP CURSOR CENTERED TO PREVENT SCREEN GETTING STUCK WHEN ROTATING PAST 2PI.
warped = true;
glutWarpPointer( widthOfMonitor / 2, heightOfMonitor / 2 );
}
// MoveForwards TRIGGERS IF W OR S IS PRESSED AND MOVES FORWARD OR BACKWARDS
// IN THE DIRECTION FACED IF A CUBE IS NOT BEING BUILT, OR MOVES CUBE FORWARD
// OR BACKWARDS IN THE DIRECTION FACED IF CUBE IS BEING BUILT
void move_forward( float forwardsOrBackwards )
{
float changeInX, changeInY, changeInZ, length;
if ( cuboidBuilding == 0 )
{
//GO FORWARD/BACK RELATIVE TO CAMERA VIEW
changeInX = ( forwardsOrBackwards * cameraInformation[1][0] );
changeInY = ( forwardsOrBackwards * cameraInformation[1][1] );
changeInZ = ( forwardsOrBackwards * cameraInformation[1][2] );
//NORMALIZE MOVEMENT
length = sqrt ( pow ( changeInX, 2.0 ) + pow ( changeInY, 2.0 ) + pow ( changeInZ, 2.0 ) );
changeInX = changeInX / length;
changeInY = changeInY / length;
changeInZ = changeInZ / length;
//SET SENSITIVITY AND ADD CHANGE FROM STARTING POSITION TO STARTING POSITION TO GET CURRENT POSITION
cameraInformation[0][0] += changeInX * movementSpeed;
cameraInformation[0][1] += changeInY * movementSpeed;
cameraInformation[0][2] += changeInZ * movementSpeed;
}
}
// move_left TRIGGERS IF A OR D IS PRESSED AND MOVES LEFT OR RIGHT TO THE
// DIRECTION FACED IF A CUBE IS NOT BEING BUILT, OR MOVES CUBE
// LEFT OR RIGHT OF THE DIRECTION FACED IF CUBE IS BEING BUILT
void move_left( float forwardsOrBackwards )
{
float changeInX, changeInY, length;
if ( cuboidBuilding == 0 )
{
//GO LEFT/RIGHT RELATIVE TO CAMERA VIEW
changeInX = ( -forwardsOrBackwards * cameraInformation[1][1] );
changeInY = ( forwardsOrBackwards * cameraInformation[1][0] );
//NORMALIZE MOVEMENT
length = sqrt ( pow ( changeInX, 2.0 ) + pow ( changeInY, 2.0 ) );
changeInX = changeInX / length;
changeInY = changeInY / length;
//SET SENSITIVITY AND ADD CHANGE FROM STARTING POSITION TO STARTING POSITION TO GET CURRENT POSITION
cameraInformation[0][0] += changeInX * movementSpeed;
cameraInformation[0][1] += changeInY * movementSpeed;
}
}
// move_up TRIGGERS IF Q OR E IS PRESSED AND MOVES VERTICALLY UP OR DOWN
// IF A CUBE IS NOT BEING BUILT, OR MOVES CUBE VERTICALLY UP OR DOWN IF CUBE IS BEING BUILT
void move_up( float forwardsOrBackwards )
{
//MOVEMENT AND MAKING CUBE AS THE DIRECTION MOVED IS ALWAYS PARRALEL TO Z COORDS, SO NO CONVERSION FROM CAMERA TO BOX IS REQUIRED
float changeInZ, length;
//GO UP/DOWN RELATIVE TO CAMERA VIEW
changeInZ = ( forwardsOrBackwards );
//NORMALIZE MOVEMENT
length = sqrt( pow ( changeInZ, 2.0 ) );
changeInZ = changeInZ / length;
//SET SENSITIVITY
if ( cuboidBuilding == 0 )
cameraInformation[0][2] += changeInZ * movementSpeed;
//ADD CHANGE FROM STARTING POSITION TO STARTING POSITION TO GET CURRENT POSITION
}
// keyboard TRIGGERS IF A KEY ON THE KEYBOARD IS PRESSED,
// THEN PASSES TO A FUNCTION THAT PROCESSES THE KEY PRESSED,
// ALSO UPDATES THE LOCATION OF CAMERA IF MOVEMENT KEYS ARE PRESSED
void keyboard( unsigned char key, int x, int y )
{
int forwardsOrBackwards; //FORWARD OR BACKWORDS.
//PREVENT A POTENTIAL DIVIDE BY 0 ERROR BY SETTING 0 DIRECTIONS TO VERY SMALL DIRECTIONS.
for ( int i = 0; i <= 2; i++ )
{
if ( cameraInformation[1][i] > -1E-5 && cameraInformation[1][i] < 1E-5 )
cameraInformation[1][i] = 1E-4;
}
switch ( key )
{
case 122: case 90: //z
if ( movementSpeed < 0.5 )
movementSpeed = 1.0;
else
movementSpeed = 0.025;
break;
case 119: case 52: forwardsOrBackwards = 1; move_forward ( forwardsOrBackwards ); break; //w
case 115: case 83: forwardsOrBackwards = -1;move_forward ( forwardsOrBackwards ); break; //s
case 97 : case 65: forwardsOrBackwards = 1; move_left ( forwardsOrBackwards ); break; //a
case 100: case 68: forwardsOrBackwards = -1;move_left ( forwardsOrBackwards ); break; //d
case 113: case 81: forwardsOrBackwards = -1;move_up ( forwardsOrBackwards ); break; //q
case 101: case 69: forwardsOrBackwards = 1; move_up ( forwardsOrBackwards ); break; //e
case 27 : exit ( 0 ); //esc CLOSE PROGRAM
}
if ( cuboidBuilding == 0 ) //IF NOT BUILDING A CUBE, MOVE CAMERA COORDS BY THE AMOUNT THEY HAVE CHANGED
{
for ( int i = 0; i <=2; i++)
{
cameraInformation[2][i] = ORIGINAL_CAMERA_LOCATION[i] + cameraInformation[0][i];
}
}
}
// cuboid TAKES INPUTS OF CENTER OF CUBE, SIZE OF CUBE AND COLOURS OF EACH FACE
// THEN PRODUCES A CUBE BY SPLITING EACH FACE UP INTO TWO TRIANGLES
void cuboid
(
float OCX, float OCY, float OCZ,
float xsize, float ysize, float zsize,
float TR, float TG, float TB,
float BR, float BG, float BB,
float FR, float FG, float FB,
float BWR, float BWG, float BWB,
float LR, float LG, float LB,
float RR, float RG, float RB
)
{
glBegin( GL_TRIANGLES );
//MAKE TRIANGLES IN SHAPE OF A CUBE BY SPECIFYING VERTICES OF TRIANGLES
glColor3f ( TR, TG, TB ); //TOP
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ + zsize );
glColor3f ( BR, BG, BB ); //BOTTOM
glVertex3f( OCX - xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ - zsize );
glColor3f ( FR, FG, FB ); //FORWARDS
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ - zsize );
glColor3f ( BWR, BWG, BWB ); //BACKWARDS
glVertex3f( OCX - xsize, OCY + ysize, OCZ + zsize);
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ - zsize );
glColor3f ( LR, LG, LB ); //LEFT
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX - xsize, OCY + ysize, OCZ + zsize );
glColor3f ( RR, RG, RB ); //RIGHT
glVertex3f( OCX + xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY - ysize, OCZ + zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ - zsize );
glVertex3f( OCX + xsize, OCY + ysize, OCZ + zsize );
glEnd( );
}
// display TAKES THE ARRAYS OF CUBE AND MOLECULE LOCATIONS, SIZE AND
// COLOURS THEN RENDERS AND CHECKS IF MOLECULES ARE COLLIDING WITH A CUBE
void display ( )
{
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
//SET THE PERSPECTIVE
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
int widthOfMonitor = glutGet( GLUT_WINDOW_WIDTH );
int heightOfMonitor = glutGet( GLUT_WINDOW_HEIGHT );
gluPerspective( 90, //FOV
widthOfMonitor / heightOfMonitor, //DISPLAY ASPECT
0.01, //NEAR CLIP
20000.0 ); //FAR CLIP
//MOVE CAMERA
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt
(
cameraInformation[2][0], cameraInformation[2][1], cameraInformation[2][2], //Camera location
cameraInformation[2][0] + cameraInformation[1][0],
cameraInformation[2][1] + cameraInformation[1][1],
cameraInformation[2][2] + cameraInformation[1][2], //LOOK AT
0.0, 0.0, 1.0
); //VERTICAL
glColorMaterial ( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE ) ;
glEnable ( GL_COLOR_MATERIAL ) ;
glEnable( GL_DEPTH_TEST ); //RENDER OBJECTS CLOSEST TO CAMERA INFRONT OF OBJECTS FURTHER AWAY
//SET EDGES OF THE MAP
glColor3d( 1.0, 0.0, 0.0 );
cuboid
(
0.0, 0.0, 0.0,
MAPSIZE, MAPSIZE, MAPSIZE,
0.0, 0.0, 1.0,
0.0, 1.0, 0.0,
0.0, 1.0, 0.0,
0.0, 1.0, 0.0,
0.0, 1.0, 0.0,
0.0, 1.0, 0.0
);
glutSwapBuffers();
}
void timer( int value )
{
glutPostRedisplay();
glutTimerFunc( 16, timer, 0 );
}
int main ( int argc, char **argv )
{
glutInit( &argc, argv );
glutInitDisplayMode( GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA );
glutInitWindowSize( 600, 600 );
glutInitWindowPosition( 0, 0 );
glutCreateWindow( "SQUARE" );
glutKeyboardFunc( keyboard );
glutDisplayFunc( display );
glutPassiveMotionFunc( passiveMotion );
glutTimerFunc( 0, timer, 0 );
glutSetCursor( GLUT_CURSOR_NONE );
glutMainLoop( );
}
glutPostRedisplay 是这里的主要内容。您甚至可以 post 它来自内部显示功能。没有它，它将无法工作。