b3f5f81999-08-10Henrik Grubbström (Grubba) /* * $Id: GLU.pmod,v 1.2 1999/08/10 17:13:31 grubba Exp $ * * GL Utilities module. */ #if constant(GL)
ea27a51999-07-24Johan Schön import GL; #ifndef M_PI #define M_PI 3.1415926536 #endif #define EPS 0.00001 void gluLookAt(float eyex, float eyey, float eyez, float centerx, float centery, float centerz, float upx, float upy, float upz) { array(float) m=allocate(16); array(float) x=allocate(3), y=allocate(3), z=allocate(3); float mag; /* Make rotation matrix */ /* Z vector */ z[0] = eyex - centerx; z[1] = eyey - centery; z[2] = eyez - centerz; mag = sqrt( z[0]*z[0] + z[1]*z[1] + z[2]*z[2] ); if (mag) { /* mpichler, 19950515 */ z[0] /= mag; z[1] /= mag; z[2] /= mag; } /* Y vector */ y[0] = upx; y[1] = upy; y[2] = upz; /* X vector = Y cross Z */ x[0] = y[1]*z[2] - y[2]*z[1]; x[1] = -y[0]*z[2] + y[2]*z[0]; x[2] = y[0]*z[1] - y[1]*z[0]; /* Recompute Y = Z cross X */ y[0] = z[1]*x[2] - z[2]*x[1]; y[1] = -z[0]*x[2] + z[2]*x[0]; y[2] = z[0]*x[1] - z[1]*x[0]; /* mpichler, 19950515 */ /* cross product gives area of parallelogram, which is < 1.0 for * non-perpendicular unit-length vectors; so normalize x, y here */ mag = sqrt( x[0]*x[0] + x[1]*x[1] + x[2]*x[2] ); if (mag) { x[0] /= mag; x[1] /= mag; x[2] /= mag; } mag = sqrt( y[0]*y[0] + y[1]*y[1] + y[2]*y[2] ); if (mag) { y[0] /= mag; y[1] /= mag; y[2] /= mag; } #define M(row,col) m[col*4+row] M(0,0) = x[0]; M(0,1) = x[1]; M(0,2) = x[2]; M(0,3) = 0.0; M(1,0) = y[0]; M(1,1) = y[1]; M(1,2) = y[2]; M(1,3) = 0.0; M(2,0) = z[0]; M(2,1) = z[1]; M(2,2) = z[2]; M(2,3) = 0.0; M(3,0) = 0.0; M(3,1) = 0.0; M(3,2) = 0.0; M(3,3) = 1.0; #undef M glMultMatrix( m ); /* Translate Eye to Origin */ glTranslate( -eyex, -eyey, -eyez ); } void gluOrtho2D(float left, float right, float bottom, float top) { glOrtho( left, right, bottom, top, -1.0, 1.0 ); } void gluPerspective(float fovy, float aspect, float zNear, float zFar) { float xmin, xmax, ymin, ymax; ymax = zNear * tan( fovy * M_PI / 360.0 ); ymin = -ymax; xmin = ymin * aspect; xmax = ymax * aspect; glFrustum( xmin, xmax, ymin, ymax, zNear, zFar ); } void gluPickMatrix(float x, float y, float width, float height, array(int) viewport) { array(float) m=allocate(16); float sx, sy; float tx, ty; sx = viewport[2] / width; sy = viewport[3] / height; tx = (viewport[2] + 2.0 * (viewport[0] - x)) / width; ty = (viewport[3] + 2.0 * (viewport[1] - y)) / height; #define M(row,col) m[col*4+row] M(0,0) = sx; M(0,1) = 0.0; M(0,2) = 0.0; M(0,3) = tx; M(1,0) = 0.0; M(1,1) = sy; M(1,2) = 0.0; M(1,3) = ty; M(2,0) = 0.0; M(2,1) = 0.0; M(2,2) = 1.0; M(2,3) = 0.0; M(3,0) = 0.0; M(3,1) = 0.0; M(3,2) = 0.0; M(3,3) = 1.0; #undef M glMultMatrix( m ); } static void transform_point(array(float) out, array(float)m, array(float) in) { #define M(row,col) m[col*4+row] out[0] = M(0,0) * in[0] + M(0,1) * in[1] + M(0,2) * in[2] + M(0,3) * in[3]; out[1] = M(1,0) * in[0] + M(1,1) * in[1] + M(1,2) * in[2] + M(1,3) * in[3]; out[2] = M(2,0) * in[0] + M(2,1) * in[1] + M(2,2) * in[2] + M(2,3) * in[3]; out[3] = M(3,0) * in[0] + M(3,1) * in[1] + M(3,2) * in[2] + M(3,3) * in[3]; #undef M } array(float) gluProject(float objx, float objy, float objz, array(float) model, array(float) proj, array(int) viewport) { array(float) in=allocate(4),out=allocate(4); in[0]=objx; in[1]=objy; in[2]=objz; in[3]=1.0; transform_point(out,model,in); transform_point(in,proj,out); if (in[3]==0.0) return 0; in[0]/=in[3]; in[1]/=in[3]; in[2]/=in[3]; return ({ viewport[0]+(1+in[0])*viewport[2]/2, viewport[1]+(1+in[1])*viewport[3]/2, (1+in[2])/2 }); } // array(float) gluUnProject(float winx,float winy,float winz, // array(float) model, array(float) proj, // array(int) viewport) // { // array(float) // m=allocate(16), // A=allocate(16), // in=allocate(4), // out=allocate(4); // in[0]=(winx-viewport[0])*2/viewport[2] - 1.0; // in[1]=(winy-viewport[1])*2/viewport[3] - 1.0; // in[2]=2*winz - 1.0; // in[3]=1.0; // matmul(A,proj,model); // invert_matrix(A,m); // transform_point(out,m,in); // if (out[3]==0.0) // return GL_FALSE; // return ({ out[0]/out[3], out[1]/out[3], out[2]/out[3] }); // }
b3f5f81999-08-10Henrik Grubbström (Grubba)  #endif /* constant(GL) */