C++ 使用glOrtho缩放到鼠标位置
目前，我正在使用glOrtho缩放和平移正在渲染的2D图形 我已将视口设置为标准宽度和高度。然后，我将glOrtho设置为使我的frustrum使屏幕坐标与世界坐标匹配C++ 使用glOrtho缩放到鼠标位置,c++,opengl,zooming,mouse,C++,Opengl,Zooming,Mouse,目前，我正在使用glOrtho缩放和平移正在渲染的2D图形 我已将视口设置为标准宽度和高度。然后，我将glOrtho设置为使我的frustrum使屏幕坐标与世界坐标匹配 glViewport(0, 0, window_width,window_height); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glOrtho(0, window_width,window_height,0 , 100, -100); 当我在我的鼠标回调中执行缩放功能
glViewport(0, 0, window_width,window_height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, window_width,window_height,0 , 100, -100);
glOrtho( 0 * zoomOut,
window_width * zoomOut,
window_height * zoomOut,
0 * zoomOut,
100, -100);
void ZoomOrtho(){ //ON MOUSE CLICK.....
if (zooming == false){
keyStore.LMx = keyStore.Mx; //store mouse pos for next comparison
keyStore.LMy = keyStore.My;
//get mouse pos
mouseStoreX = keyStore.Mx;//mouse pos at this moment
mouseStoreY = keyStore.My;
//get current projection matrices
glGetDoublev( GL_MODELVIEW_MATRIX, modelview );
glGetDoublev( GL_PROJECTION_MATRIX, projection );
glGetIntegerv( GL_VIEWPORT, viewport );
//flip Y for opengl reasons
winY = (float)viewport[3] - winY;
//get world mouse coordinate
gluUnProject( mouseStoreX, mouseStoreY , 0.0, modelview, projection, viewport, &posX_,&posY_, &posZ_);
// calc difference between mouse world pos and centre of 'camera'
dx = posX_ - FS.centerX;
dy = posY_ - FS.centerY;
}
//ON DRAG......
zooming = true;
//do mouse movement detection and increment zoomOut
//#################################################
int xDiff = keyStore.Mx - keyStore.LMx; //mouse drag difference in screen space just for incrementing zoom
int yDiff = keyStore.My - keyStore.LMy; //
if (xDiff > 0 && (zoomFactor >= 0.5 ) ) {
zoomFactor -= zoomInc;
if (zoomFactor < 0.5 ) {zoomFactor = 0.5;}
}
else if (xDiff < 0 && (zoomFactor <= 2.0 )) {
zoomFactor += zoomInc;
if (zoomFactor > 2.0){zoomFactor = 2.0;}
}
//#################################################
//fill structure with clipping plane values. zooms ortho projection and keeps mouse pos anchored.
FS.left = ((FS.centerX - dx - (window_width/2.0))*zoomFactor) +dx;
FS.right = ((FS.centerX -dx + (window_width/2.0))*zoomFactor)+dx ;
FS.bottom = ((FS.centerY -dy + (window_width/2.0))*zoomFactor)+dy;
FS.top = ((FS.centerY -dy - (window_width/2.0))*zoomFactor) +dy;
// store last mouse pos for next comparison.
keyStore.LMx = keyStore.Mx;
keyStore.LMy = keyStore.My;
}
void zoomRelease(){
cout << " releasing" << std::endl;
//set zoom to false so we know we are not draggin mouse anymore.
zooming = false;
keyStore.LMx = 0;
keyStore.LMy = 0;
// recenter by taking midpoint between new left and right clipping planes so dx has a reference point
FS.centreX = (FS.right-FS.left)/2.0;
}
void DrawGui(){
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(FS.left, FS.right,FS.bottom, FS.top, 1, -1);
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
//do drawing
}
void zoomotho（）{//鼠标单击。。。。。
如果（缩放==假）{
keyStore.LMx=keyStore.Mx；//存储鼠标位置以便下次比较
keyStore.LMy=keyStore.My；
//获取鼠标位置
mouseStoreX=keyStore.Mx；//此时鼠标位置
mouseStoreY=keyStore.My；
//获取当前投影矩阵
glGetDoublev（GL_模型视图_矩阵，模型视图）；
glGetDoublev（GL_投影矩阵，投影）；
glGetIntegerv（GL_视口，视口）；
//出于opengl的原因翻转Y
winY=（浮动）视口[3]-winY；
//获取世界鼠标坐标
gluUnProject（mouseStoreX、mouseStoreY、0.0、modelview、投影、视口和posX、posY和posZ）；
//鼠标世界位置和“相机”中心之间的计算差异
dx=posX_u3;-FS.centerX；
dy=posY_ufs.centerY；
}
//拖拉。。。。。。
缩放=真；
//执行鼠标移动检测和增量缩放
//#################################################
int xDiff=keyStore.Mx-keyStore.LMx；//鼠标拖动屏幕空间中的差异只是为了增加缩放
int-yDiff=keyStore.My-keyStore.LMy//
如果（xDiff>0&（zoomFactor>=0.5））{
zoomFactor-=zoomInc；
如果（zoomFactor<0.5）{zoomFactor=0.5；}
}
else如果（xDiff<0&（zoomFactor 2.0）{zoomFactor=2.0；}
}
//#################################################
//用剪切平面值填充结构。缩放正交投影并保持鼠标位置固定。
FS.left=（（FS.centerX-dx-（窗口宽度/2.0））*zoomFactor）+dx；
FS.right=（（FS.centerX-dx+（窗口宽度/2.0））*zoomFactor）+dx；
FS.bottom=（（FS.centerY-dy+（窗口宽度/2.0））*zoomFactor）+dy；
FS.top=（（FS.centerY-dy-（窗口宽度/2.0））*zoomFactor）+dy；
//存储最后一个鼠标位置以便下次比较。
keyStore.LMx=keyStore.Mx；
keyStore.LMy=keyStore.My；
}
void zoomRelease（）{
cout我假设当你进行第二次点击时，你正在将其值存储到mouseStoreXY中。如果是这样，这会导致跳转。你在用旧mouseStoreXY的偏移量绘图，然后突然偏移到新的mouseStoreXY
解决方案是持久存储投影矩阵输入，然后在每一帧上增量修改它们。试一试：
// g++ main.cpp -o main -lglut -lGL && ./main
#include <GL/glut.h>
double centerX = 0, centerY = 0;
double width = 0, height = 0;
void mouse( int button, int state, int mx, int my )
{
// flip mouse y axis so up is +y
my = glutGet( GLUT_WINDOW_HEIGHT ) - my;
// convert mouse coords to (-1/2,-1/2)-(1/2, 1/2) box
double x = ( mx / (double)glutGet( GLUT_WINDOW_WIDTH ) ) - 0.5;
double y = ( my / (double)glutGet( GLUT_WINDOW_HEIGHT ) ) - 0.5;
if( GLUT_UP == state )
{
double preX = ( x * width );
double preY = ( y * height );
double zoomFactor = 1.5;
if( button == GLUT_LEFT_BUTTON )
{
// zoom in
width /= zoomFactor;
height /= zoomFactor;
}
if( button == GLUT_RIGHT_BUTTON )
{
// zoom out
width *= zoomFactor;
height *= zoomFactor;
}
double postX = ( x * width );
double postY = ( y * height );
// recenter
centerX += ( preX - postX );
centerY += ( preY - postY );
}
glutPostRedisplay();
}
void display()
{
glClear( GL_COLOR_BUFFER_BIT );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
glOrtho
(
centerX - ( width / 2.0 ),
centerX + ( width / 2.0 ),
centerY - ( height / 2.0 ),
centerY + ( height / 2.0 ),
-1,
1
);
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
glColor3ub( 255, 0, 0 );
glBegin( GL_TRIANGLES );
glVertex2i( 0, 0 );
glVertex2i( 150, 0 );
glVertex2i( 0, 150 );
glVertex2i( 0, 0 );
glVertex2i( -150, 0 );
glVertex2i( 0, -150 );
glEnd();
glutSwapBuffers();
}
int main( int argc, char **argv )
{
glutInit( &argc, argv );
glutInitDisplayMode( GLUT_RGBA | GLUT_DOUBLE );
glutInitWindowSize( 600, 600 );
glutCreateWindow( "GLUT" );
glutDisplayFunc( display );
glutMouseFunc( mouse );
width = glutGet( GLUT_WINDOW_WIDTH );
height = glutGet( GLUT_WINDOW_HEIGHT );
glutMainLoop();
return 0;
}
// g++ main.cpp -o main -lglut -lGL && ./main
#include <GL/glut.h>
#include <cmath>
void getMouseCoords( int mx, int my, double& x, double& y )
{
// flip mouse y axis so up is +y
my = glutGet( GLUT_WINDOW_HEIGHT ) - my;
// convert mouse coords to (-1/2,-1/2)-(1/2, 1/2) box
x = ( mx / (double)glutGet( GLUT_WINDOW_WIDTH ) ) - 0.5;
y = ( my / (double)glutGet( GLUT_WINDOW_HEIGHT ) ) - 0.5;
}
int btn;
double baseX, baseY;
double baseWidth, baseHeight;
double centerX = 0, centerY = 0;
double width = 0, height = 0;
void mouse( int button, int state, int mx, int my )
{
baseWidth = width;
baseHeight = height;
btn = button;
getMouseCoords( mx, my, baseX, baseY );
}
void motion( int mx, int my )
{
if( btn != GLUT_LEFT_BUTTON )
{
return;
}
double x, y;
getMouseCoords( mx, my, x, y );
double preX = ( baseX * width );
double preY = ( baseY * height );
double zoomFactor = exp( baseY - y );
width = baseWidth * zoomFactor;
height = baseHeight * zoomFactor;
double postX = ( baseX * width );
double postY = ( baseY * height );
// recenter
centerX += ( preX - postX );
centerY += ( preY - postY );
glutPostRedisplay();
}
void display()
{
glClear( GL_COLOR_BUFFER_BIT );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
glOrtho
(
centerX - ( width / 2.0 ),
centerX + ( width / 2.0 ),
centerY - ( height / 2.0 ),
centerY + ( height / 2.0 ),
-1,
1
);
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
glColor3ub( 255, 0, 0 );
glBegin( GL_TRIANGLES );
glVertex2i( 0, 0 );
glVertex2i( 150, 0 );
glVertex2i( 0, 150 );
glVertex2i( 0, 0 );
glVertex2i( -150, 0 );
glVertex2i( 0, -150 );
glEnd();
glutSwapBuffers();
}
int main( int argc, char **argv )
{
glutInit( &argc, argv );
glutInitDisplayMode( GLUT_RGBA | GLUT_DOUBLE );
glutInitWindowSize( 600, 600 );
glutCreateWindow( "GLUT" );
glutDisplayFunc( display );
glutMouseFunc( mouse );
glutMotionFunc( motion );
width = glutGet( GLUT_WINDOW_WIDTH );
height = glutGet( GLUT_WINDOW_HEIGHT );
glutMainLoop();
return 0;
}
//g++main.cpp-o main-lglut-lGL&&./main
#包括
双中心X=0，中心Y=0；
双宽=0，高=0；
无效鼠标（int按钮、int状态、int mx、int my）
{
//翻转鼠标y轴，使其向上为+y
my=glutGet（GLUT\u窗口\u高度）-my；
//将鼠标坐标转换为（-1/2，-1/2）-（1/2，1/2）框
双x=（mx/（双）glutGet（GLUT_窗口_宽度））-0.5；
双y=（我的/（双）glutGet（GLUT_窗口_高度））-0.5；
if（GLUT_UP==状态）
{
双preX=（x*宽度）；
双猎物=（y*高度）；
双变焦因子=1.5；
如果（按钮==GLUT\u左按钮）
{
//放大
宽度/=缩放因子；
高度/=动物因子；
}
如果（按钮==GLUT\u右按钮）
{
//缩小
宽度*=缩放因子；
高度*=缩放因子；
}
双postX=（x*宽度）；
双立柱y=（y*高度）；
//重新居中
centerX+=（前置-后置）；
centerY+=（猎物-postY）；
}
再发现（）；
}
无效显示（）
{
glClear（GLU颜色缓冲位）；
glMatrixMode（GL_投影）；
glLoadIdentity（）；
格洛托
(
centerX-（宽度/2.0），
centerX+（宽度/2.0），
中心-（高度/2.0），
centerY+（高度/2.0），
-1,
1.
);
glMatrixMode（GLU模型视图）；
glLoadIdentity（）；
glColor3ub（255,0,0）；
glBegin（GL_三角形）；
glVertex2i（0,0）；
glVertex2i（150,0）；
glVertex2i（0150）；
glVertex2i（0,0）；
glVertex2i（-150,0）；
glVertex2i（0，-150）；
格伦德（）；
glutSwapBuffers（）；
}
int main（int argc，字符**argv）
{
glutInit（&argc，argv）；
glutInitDisplayMode（GLUT_RGBA | GLUT_DOUBLE）；
glutInitWindowSize（600600）；
GLUT（GLUT）；
glutDisplayFunc（显示器）；
glutMouseFunc（小鼠）；
宽度=glutGet（GLUT\u窗口\u宽度）；
高度=glutGet（GLUT\u窗口\u高度）；
glutMainLoop（）；
返回0；
}
试一试：
// g++ main.cpp -o main -lglut -lGL && ./main
#include <GL/glut.h>
double centerX = 0, centerY = 0;
double width = 0, height = 0;
void mouse( int button, int state, int mx, int my )
{
// flip mouse y axis so up is +y
my = glutGet( GLUT_WINDOW_HEIGHT ) - my;
// convert mouse coords to (-1/2,-1/2)-(1/2, 1/2) box
double x = ( mx / (double)glutGet( GLUT_WINDOW_WIDTH ) ) - 0.5;
double y = ( my / (double)glutGet( GLUT_WINDOW_HEIGHT ) ) - 0.5;
if( GLUT_UP == state )
{
double preX = ( x * width );
double preY = ( y * height );
double zoomFactor = 1.5;
if( button == GLUT_LEFT_BUTTON )
{
// zoom in
width /= zoomFactor;
height /= zoomFactor;
}
if( button == GLUT_RIGHT_BUTTON )
{
// zoom out
width *= zoomFactor;
height *= zoomFactor;
}
double postX = ( x * width );
double postY = ( y * height );
// recenter
centerX += ( preX - postX );
centerY += ( preY - postY );
}
glutPostRedisplay();
}
void display()
{
glClear( GL_COLOR_BUFFER_BIT );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
glOrtho
(
centerX - ( width / 2.0 ),
centerX + ( width / 2.0 ),
centerY - ( height / 2.0 ),
centerY + ( height / 2.0 ),
-1,
1
);
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
glColor3ub( 255, 0, 0 );
glBegin( GL_TRIANGLES );
glVertex2i( 0, 0 );
glVertex2i( 150, 0 );
glVertex2i( 0, 150 );
glVertex2i( 0, 0 );
glVertex2i( -150, 0 );
glVertex2i( 0, -150 );
glEnd();
glutSwapBuffers();
}
int main( int argc, char **argv )
{
glutInit( &argc, argv );
glutInitDisplayMode( GLUT_RGBA | GLUT_DOUBLE );
glutInitWindowSize( 600, 600 );
glutCreateWindow( "GLUT" );
glutDisplayFunc( display );
glutMouseFunc( mouse );
width = glutGet( GLUT_WINDOW_WIDTH );
height = glutGet( GLUT_WINDOW_HEIGHT );
glutMainLoop();
return 0;
}
// g++ main.cpp -o main -lglut -lGL && ./main
#include <GL/glut.h>
#include <cmath>
void getMouseCoords( int mx, int my, double& x, double& y )
{
// flip mouse y axis so up is +y
my = glutGet( GLUT_WINDOW_HEIGHT ) - my;
// convert mouse coords to (-1/2,-1/2)-(1/2, 1/2) box
x = ( mx / (double)glutGet( GLUT_WINDOW_WIDTH ) ) - 0.5;
y = ( my / (double)glutGet( GLUT_WINDOW_HEIGHT ) ) - 0.5;
}
int btn;
double baseX, baseY;
double baseWidth, baseHeight;
double centerX = 0, centerY = 0;
double width = 0, height = 0;
void mouse( int button, int state, int mx, int my )
{
baseWidth = width;
baseHeight = height;
btn = button;
getMouseCoords( mx, my, baseX, baseY );
}
void motion( int mx, int my )
{
if( btn != GLUT_LEFT_BUTTON )
{
return;
}
double x, y;
getMouseCoords( mx, my, x, y );
double preX = ( baseX * width );
double preY = ( baseY * height );
double zoomFactor = exp( baseY - y );
width = baseWidth * zoomFactor;
height = baseHeight * zoomFactor;
double postX = ( baseX * width );
double postY = ( baseY * height );
// recenter
centerX += ( preX - postX );
centerY += ( preY - postY );
glutPostRedisplay();
}
void display()
{
glClear( GL_COLOR_BUFFER_BIT );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
glOrtho
(
centerX - ( width / 2.0 ),
centerX + ( width / 2.0 ),
centerY - ( height / 2.0 ),
centerY + ( height / 2.0 ),
-1,
1
);
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
glColor3ub( 255, 0, 0 );
glBegin( GL_TRIANGLES );
glVertex2i( 0, 0 );
glVertex2i( 150, 0 );
glVertex2i( 0, 150 );
glVertex2i( 0, 0 );
glVertex2i( -150, 0 );
glVertex2i( 0, -150 );
glEnd();
glutSwapBuffers();
}
int main( int argc, char **argv )
{
glutInit( &argc, argv );
glutInitDisplayMode( GLUT_RGBA | GLUT_DOUBLE );
glutInitWindowSize( 600, 600 );
glutCreateWindow( "GLUT" );
glutDisplayFunc( display );
glutMouseFunc( mouse );
glutMotionFunc( motion );
width = glutGet( GLUT_WINDOW_WIDTH );
height = glutGet( GLUT_WINDOW_HEIGHT );
glutMainLoop();
return 0;
}
//g++main.cpp-o main-lglut-lGL&&./main
#包括
#包括
void getMouseCoords（int-mx、int-my、double&x、double&y）
{
//翻转鼠标y轴，使其向上为+y
my=glutGet（GLUT\u窗口\u高度）-my；
//将鼠标坐标转换为（-1/2，-1/2）-（1/2，1/2）框
x=（mx/（双）glutGet（GLUT_窗口_宽度））-0.5；
y=（我的/（双）glutGet（GLUT_窗口_高度））-0.5；
}
国际电话号码；
双基x，基y；
双底宽，底高；
双中心X=0，中心Y=0；
双宽=0，高=0；
无效鼠标（int按钮、int状态、int mx、int my）
{
baseWidth=宽度；
基准高度=高度；
btn=按钮；
GetMouseCoods（mx、my、baseX、baseY）；
}
无效运动（int mx，int my）
{
如果（btn！=GLUT\u左按钮）
{
返回；
}
双x，y；
getMouseCoords（mx，my，x，y）；
双preX=（baseX*宽度）；
双猎物=（贝西*黑格）
# Translate graphics
glTranslatef(0.0, 0.0, (self.translation[1]/100.0) * (math.tan(self.cameraPosition[0]/self.cameraPosition[1])))
glTranslatef(0.0, (self.translation[0]/100.0) * (math.tan(self.cameraPosition[0]/self.cameraPosition[1])), 0.0)
# Set Perspective
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
gluPerspective(self.zoomFactor, float(width)/float(height), self.nearPlane, self.farPlane)
# Render Scene
glMatrixMode(GL_MODELVIEW)
...Draw stuff here...