// 重置OpenGL窗口大小
void CglWnd::ReSizeGLScene( GLsizei width, GLsizei height )
{
if (height==0) // 防止被零除
{
height=1; // 将Height设为1
}
float mat_p[16];
float mat_t[16];
float mvp[16];
float aspect = (float)width/height;
glViewport(0,0,width,height); // 重置当前的视口
matIdentity(mvp);
matIdentity(mat_p);
matIdentity(mat_t);
viewHeight = 720/2;
viewWidth = viewHeight*aspect;
// 设置视口的大小
matPerspective((float*)mat_p, 90, aspect, 200.0f, 500.0f);
//设置镜头
matLookAt((float*)mat_t, 0,0,viewHeight, 0,0,0, 0,1,0);
matMult((float*)mvp, (float*)mat_p, (float*)mat_t);
//z=0 平面的投影大小
// set the transformation
glUniformMatrix4fv(viewprojLoc, 1, GL_FALSE, (float*)mvp);
resetMainTexVertex();
}
void matRotate(float* a,float* axis,float angle)
{
float mag,s,c;
float xx,yy,zz,xy,yz,zx,xs,ys,zs,one_c;
float x,y,z;
float m[16];
double rads;
x=axis[0];
y=axis[1];
z=axis[2];
rads=(double)angle*PI/180.0F;
s=(float)sin(rads);
c=(float)cos(rads);
mag=(float)sqrt(x*x+y*y+z*z);
if(mag == 0.0)
{
matIdentity(m);
return;
}
x/=mag;
y/=mag;
z/=mag;
#define M(row,col) m[(col<<2)+row]
xx=x*x;
yy=y*y;
zz=z*z;
xy=x*y;
yz=y*z;
zx=z*x;
xs=x*s;
ys=y*s;
zs=z*s;
one_c=1.0F-c;
M(0,0)=(one_c*xx)+c;
M(0,1)=(one_c*xy)-zs;
M(0,2)=(one_c*zx)+ys;
M(0,3)=0.0F;
M(1,0)=(one_c*xy)+zs;
M(1,1)=(one_c*yy)+c;
M(1,2)=(one_c*yz)-xs;
M(1,3)=0.0F;
M(2,0)=(one_c*zx)-ys;
M(2,1)=(one_c*yz)+xs;
M(2,2)=(one_c*zz)+c;
M(2,3)=0.0F;
M(3,0)=0.0F;
M(3,1)=0.0F;
M(3,2)=0.0F;
M(3,3)=1.0F;
#undef M
matProduct(NULL,a,m);
return;
}
void matInvert(float *c,float* m)
{
float det;
float tmp[16]; // allow out = in
float d12,d13,d23,d24,d34,d41;
float im11,im12,im13,im14;
#define MAT(m,r,c) (m)[((c)<<2)+(r)]
#define m11 MAT(m,0,0)
#define m12 MAT(m,0,1)
#define m13 MAT(m,0,2)
#define m14 MAT(m,0,3)
#define m21 MAT(m,1,0)
#define m22 MAT(m,1,1)
#define m23 MAT(m,1,2)
#define m24 MAT(m,1,3)
#define m31 MAT(m,2,0)
#define m32 MAT(m,2,1)
#define m33 MAT(m,2,2)
#define m34 MAT(m,2,3)
#define m41 MAT(m,3,0)
#define m42 MAT(m,3,1)
#define m43 MAT(m,3,2)
#define m44 MAT(m,3,3)
if((m41 != 0.0F) || (m42 != 0.0F) || (m43 != 0.0F) || (m44 != 1.0F))
{
matInvertEx(c,m);
return;
}
// Inverse=adjoint/det
tmp[0]=m22*m33-m23*m32;
tmp[1]=m23*m31-m21*m33;
tmp[2]=m21*m32-m22*m31;
// Compute determinant using cofactors
det=m11*tmp[0]+m12*tmp[1]+m13*tmp[2];
// Singularity test
if(det == 0.0F) matIdentity(c);
else
{
det=1.0F/det;
// Compute rest of inverse
tmp[0]*=det;
tmp[1]*=det;
tmp[2]*=det;
tmp[3]=0.0F;
im11=m11*det;
im12=m12*det;
im13=m13*det;
im14=m14*det;
tmp[4]=im13*m32-im12*m33;
tmp[5]=im11*m33-im13*m31;
tmp[6]=im12*m31-im11*m32;
tmp[7]=0.0F;
// Pre-compute 2x2 dets for first two rows when computing cofactors of last two rows.
d12=im11*m22-m21*im12;
d13=im11*m23-m21*im13;
d23=im12*m23-m22*im13;
d24=im12*m24-m22*im14;
d34=im13*m24-m23*im14;
d41=im14*m21-m24*im11;
tmp[8]=d23;
tmp[9]=-d13;
tmp[10]=d12;
tmp[11]=0.0F;
tmp[12]=-(m32*d34-m33*d24+m34*d23);
tmp[13]=(m31*d34+m33*d41+m34*d13);
tmp[14]=-(m31*d24+m32*d41+m34*d12);
tmp[15]=1.0F;
memcpy(c,tmp,sizeof(float)*16);
}
#undef m11
#undef m12
#undef m13
#undef m14
#undef m21
#undef m22
#undef m23
#undef m24
#undef m31
#undef m32
#undef m33
#undef m34
#undef m41
#undef m42
#undef m43
#undef m44
#undef MAT
return;
}
