gluUnProject function in openGL
The following piece of code gives me an error and I'm not able to understand it.
GLdouble objX,objY,objZ;
GLdouble modelvie开发者_如何学Cw1[4][4], projection1[4][4];
GLint viewport1[4];
glGetDoublev( GL_MODELVIEW_MATRIX, *modelview1 );
glGetDoublev( GL_PROJECTION_MATRIX, *projection1 );
glGetIntegerv( GL_VIEWPORT, viewport1 );
gluUnProject(x, y, z, modelview1, projection1, viewport1, objX , objY , objZ);`
The error :
error C2664: 'gluUnProject' : cannot convert parameter 4 from 'GLdouble [4][4]' to 'const GLdouble []'
It seems that variables modelview1 and projection1 have wrong type.
I found following snippet (here http://www.3dkingdoms.com/selection.html ):
// This function will find 2 points in world space that are on the line into the screen defined by screen-space( ie. window-space ) point (x,y)
double mvmatrix[16];
double projmatrix[16];
int viewport[4];
double dX, dY, dZ, dClickY; // glUnProject uses doubles, but I'm using floats for these 3D vectors
glGetIntegerv(GL_VIEWPORT, viewport);
glGetDoublev (GL_MODELVIEW_MATRIX, mvmatrix);
glGetDoublev (GL_PROJECTION_MATRIX, projmatrix);
dClickY = double (g_WindowHeight - y); // OpenGL renders with (0,0) on bottom, mouse reports with (0,0) on top
gluUnProject ((double) x, dClickY, 0.0, mvmatrix, projmatrix, viewport, &dX, &dY, &dZ);
ClickRayP1 = Vector3 ( (float) dX, (float) dY, (float) dZ );
gluUnProject ((double) x, dClickY, 1.0, mvmatrix, projmatrix, viewport, &dX, &dY, &dZ);
ClickRayP2 = Vector3 ( (float) dX, (float) dY, (float) dZ );
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