void display(void)
{
GLfloat knots[8] = {0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0};
GLfloat edgePt[5][2] = /* counter clockwise */
{{0.0, 0.0}, {1.0, 0.0}, {1.0, 1.0}, {0.0, 1.0}, {0.0, 0.0}};
GLfloat curvePt[4][2] = /* clockwise */
{{0.25, 0.5}, {0.25, 0.75}, {0.75, 0.75}, {0.75, 0.5}};
GLfloat curveKnots[8] =
{0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0};
GLfloat pwlPt[4][2] = /* clockwise */
{{0.75, 0.5}, {0.5, 0.25}, {0.25, 0.5}};
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glRotatef(330.0, 1.,0.,0.);
glScalef (0.5, 0.5, 0.5);
gluBeginSurface(theNurb);
gluNurbsSurface(theNurb, 8, knots, 8, knots,
4 * 3, 3, &ctlpoints[0][0][0],
4, 4, GL_MAP2_VERTEX_3);
gluBeginTrim (theNurb);
gluPwlCurve (theNurb, 5, &edgePt[0][0], 2, GLU_MAP1_TRIM_2);
gluEndTrim (theNurb);
gluBeginTrim (theNurb);
gluNurbsCurve (theNurb, 8, curveKnots, 2,
&curvePt[0][0], 4, GLU_MAP1_TRIM_2);
gluPwlCurve (theNurb, 3, &pwlPt[0][0], 2, GLU_MAP1_TRIM_2);
gluEndTrim (theNurb);
gluEndSurface(theNurb);
glPopMatrix();
glFlush();
}
void display(void)
{
GLfloat knots1[12] = { 0.0, 0.0, 0.0, 0.0, 0.0, 0.0
, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0 };
GLfloat knots2[8] = {0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0};
int i, j;
GLfloat edgePt[5][2] =
{{0.0, 0.0}, {1.0, 0.0}, {1.0, 1.0}, {0.0, 1.0},
{0.0, 0.0}};
GLfloat pwlPt[42][2];
for(unsigned int k = 0; k < 42; ++k)
{
pwlPt[k][0] = 0.5 + 0.3 * cos(2.0*PI*k/41.0);
pwlPt[k][1] = 0.5 + 0.3 * sin(-2.0*PI*k/41.0);
}
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glRotatef(330.0, 1.,0.,0.);
glScalef (0.3, 0.3, 0.3);
gluBeginSurface(theNurb);
gluNurbsSurface(theNurb,
12, knots1, 8, knots2,
4 * 3, 3, &ctlpoints[0][0][0],
6, 4, GL_MAP2_VERTEX_3);
// trim
gluBeginTrim (theNurb);
gluPwlCurve(theNurb, 5, &edgePt[0][0], 2, GLU_MAP1_TRIM_2);
gluEndTrim (theNurb);
gluBeginTrim (theNurb);
gluPwlCurve (theNurb, 42, &pwlPt[0][0], 2, GLU_MAP1_TRIM_2);
gluEndTrim (theNurb);
gluEndSurface(theNurb);
if (showPoints) {
glPointSize(5.0);
glDisable(GL_LIGHTING);
glColor3f(1.0, 1.0, 0.0);
glBegin(GL_POINTS);
for (i = 0; i < 8; i++) {
for (j = 0; j < 4; j++) {
glVertex3f(ctlpoints[i][j][0],
ctlpoints[i][j][1], ctlpoints[i][j][2]);
}
}
glEnd();
glEnable(GL_LIGHTING);
}
glPopMatrix();
glFlush();
}
// Called to draw scene
void RenderScene(void)
{
// Draw in Blue
glColor3ub(0,0,220);
// Clear the window with current clearing color
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// Save the modelview matrix stack
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
// Rotate the mesh around to make it easier to see
glRotatef(330.0f, 1.0f,0.0f,0.0f);
// Render the NURB
// Begin the NURB definition
gluBeginSurface(pNurb);
// Evaluate the surface
gluNurbsSurface(pNurb, // pointer to NURBS renderer
8, Knots, // No. of knots and knot array u direction
8, Knots, // No. of knots and knot array v direction
4 * 3, // Distance between control points in u dir.
3, // Distance between control points in v dir.
&ctrlPoints[0][0][0], // Control points
4, 4, // u and v order of surface
GL_MAP2_VERTEX_3); // Type of surface
// Outer area, include entire curve
gluBeginTrim (pNurb);
gluPwlCurve (pNurb, 5, &outsidePts[0][0], 2, GLU_MAP1_TRIM_2);
gluEndTrim (pNurb);
// Inner triangluar area
gluBeginTrim (pNurb);
gluPwlCurve (pNurb, 4, &insidePts[0][0], 2, GLU_MAP1_TRIM_2);
gluEndTrim (pNurb);
// Done with surface
gluEndSurface(pNurb);
// Restore the modelview matrix
glPopMatrix();
// Dispalay the image
glutSwapBuffers();
}
void Sample_12_8::draw()
{
int i, j;
GLfloat knots[8] = {0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0};
GLfloat edgePt[5][2] = /* counter clockwise */
{{0.0, 0.0}, {1.0, 0.0}, {1.0, 1.0}, {0.0, 1.0}, {0.0, 0.0}};
GLfloat curvePt[4][2] = /* clockwise */
{{0.25, 0.5}, {0.25, 0.75}, {0.75, 0.75}, {0.75, 0.5}};
GLfloat curveKnots[8] =
{0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0};
GLfloat pwlPt[4][2] = /* clockwise */
{{0.75, 0.5}, {0.5, 0.25}, {0.25, 0.5}};
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glRotatef(330.0, 1.,0.,0.);
glScalef (0.5, 0.5, 0.5);
gluBeginSurface(m_theNurb);
gluNurbsSurface(m_theNurb, 8, knots, 8, knots,
4 * 3, 3, &m_ctlpoints[0][0][0],
4, 4, GL_MAP2_VERTEX_3);
gluBeginTrim (m_theNurb);
gluPwlCurve (m_theNurb, 5, &edgePt[0][0], 2, GLU_MAP1_TRIM_2);
gluEndTrim (m_theNurb);
gluBeginTrim (m_theNurb);
gluNurbsCurve (m_theNurb, 8, curveKnots, 2,
&curvePt[0][0], 4, GLU_MAP1_TRIM_2);
gluPwlCurve (m_theNurb, 3, &pwlPt[0][0], 2, GLU_MAP1_TRIM_2);
gluEndTrim (m_theNurb);
gluEndSurface(m_theNurb);
if (m_showPoints) {
glPointSize(5.0);
glDisable(GL_LIGHTING);
glColor3f(1.0, 1.0, 0.0);
glBegin(GL_POINTS);
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
glVertex3f(m_ctlpoints[i][j][0],
m_ctlpoints[i][j][1], m_ctlpoints[i][j][2]);
}
}
glEnd();
glEnable(GL_LIGHTING);
}
glPopMatrix();
}
void RenderScene(void)
{
glColor3ub(0,0,220);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glRotatef(330.0f, 1.0f, 0.0f, 0.0f);
//修剪框是一个闭合的环
//外修剪框
GLfloat outSidePts[5][2] =
{{0.0f, 0.0f}, {1.0f, 0.0f}, {1.0f, 1.0f}, {0.0f, 1.0f}, {0.0f, 0.0f}};
//内修剪框
GLfloat inSidePts[4][2] =
{{0.25f, 0.25f}, { 0.5f, 0.5f}, {0.75f, 0.25f},{0.25f, 0.25f} };
gluBeginSurface(pNurb);
//定义NURBS表面
gluNurbsSurface(pNurb,
8, Knots, //u定义域内的结点个数，以及结点序列
8, Knots,//v定义域内的结点个数，以及结点序列
4 * 3, //u方向上的控制点间隔
3, //v方向上的控制点间隔
&ctrlPoints[0][0][0], //控制点数组
4, 4, //u v的次数
GL_MAP2_VERTEX_3);//产生的类型
//开始修剪
gluBeginTrim(pNurb);
gluPwlCurve(pNurb,
5, //修剪点的个数
&outSidePts[0][0], //修剪点数组
2, //点之间的间隔
GLU_MAP1_TRIM_2);//修剪的类型
gluEndTrim(pNurb);
gluBeginTrim(pNurb);
gluPwlCurve(pNurb, 4, &inSidePts[0][0], 2, GLU_MAP1_TRIM_2);
gluEndTrim(pNurb);
gluEndSurface(pNurb);
DrawPoints();
glPopMatrix();
glutSwapBuffers();
}
/* nurb:BeginTrim() -> nurb */
static int luaglu_begin_trim(lua_State *L)
{
LuaGLUnurb *lnurb=luaglu_checknurb(L,1);
gluBeginTrim(lnurb->nurb);
lua_pushvalue(L,1);
return 1;
}
void render_scene()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
/* Render trimmed surface */
gluBeginSurface(nurb);
gluNurbsSurface(nurb, 8, knots, 8, knots, 4*3, 3, &ctlpoints[0][0][0], 4, 4, GLU_MAP2_VERTEX_3);
gluBeginTrim(nurb);
gluPwlCurve(nurb, 5, &edgePt[0][0], 2, GLU_MAP1_TRIM_2);
gluEndTrim(nurb);
gluBeginTrim(nurb);
gluNurbsCurve(nurb, 8, curveKnots, 2, &curvePt[0][0], 4, GLU_MAP1_TRIM_2);
gluPwlCurve (nurb, 3, &pwlPt[0][0], 2, GLU_MAP1_TRIM_2);
gluEndTrim(nurb);
gluEndSurface(nurb);
/* Flush all drawings */
glFlush();
}
/* Execute a bgn/endtrim pair for the given trim curve structure. */
void dotrim(TrimCurve *trim_curve) {
int i;
gluBeginTrim(nurbsflag);
for (i=0; i<trim_curve->pieces; i++) {
if (trim_curve->trim[i].type == PWL) {
gluPwlCurve(nurbsflag, trim_curve->trim[i].points,
&trim_curve->trim[i].point[0][0],
2, GLU_MAP1_TRIM_2);
} else {
gluNurbsCurve(nurbsflag, ELEMENTS(trimknots),trimknots,
2,&trim_curve->trim[i].point[0][0],
trim_curve->trim[i].points, GLU_MAP1_TRIM_2);
}
}
gluEndTrim(nurbsflag);
}
static int tolua_glu_gluBeginTrim00(lua_State* tolua_S)
{
#ifndef TOLUA_RELEASE
tolua_Error tolua_err;
if (
!tolua_isusertype(tolua_S,1,"GLUnurbsObj",0,&tolua_err) ||
!tolua_isnoobj(tolua_S,2,&tolua_err)
)
goto tolua_lerror;
else
#endif
{
GLUnurbsObj* nobj = ((GLUnurbsObj*) tolua_tousertype(tolua_S,1,0));
{
gluBeginTrim(nobj);
}
}
return 0;
#ifndef TOLUA_RELEASE
tolua_lerror:
tolua_error(tolua_S,"#ferror in function 'gluBeginTrim'.",&tolua_err);
return 0;
#endif
}
void ON_GL( const ON_BrepFace& face,
GLUnurbsObj* nobj // created with gluNewNurbsRenderer )
)
{
bool bSkipTrims = false;
const ON_Mesh* mesh;
mesh = face.Mesh(ON::render_mesh);
if ( mesh )
{
// use saved render mesh
ON_GL(*mesh);
}
else
{
// use (slow and buggy) glu trimmed NURBS rendering
double knot_scale[2][2] = {{0.0,1.0},{0.0,1.0}};
const ON_Brep* brep = face.Brep();
if ( !brep )
return;
// untrimmed surface
{
ON_NurbsSurface tmp_nurbssrf;
const ON_Surface* srf = brep->m_S[face.m_si];
const ON_NurbsSurface* nurbs_srf = ON_NurbsSurface::Cast(srf);
if ( !nurbs_srf )
{
// attempt to get NURBS form of this surface
if ( srf->GetNurbForm( tmp_nurbssrf ) )
nurbs_srf = &tmp_nurbssrf;
}
if ( !nurbs_srf )
return;
gluBeginSurface( nobj );
ON_GL( *nurbs_srf,
nobj,
(nurbs_srf->IsRational()) ? GL_MAP2_VERTEX_4 : GL_MAP2_VERTEX_3,
true, knot_scale[0], knot_scale[1]
);
}
if ( bSkipTrims || brep->FaceIsSurface( face.m_face_index ) ) {
gluEndSurface( nobj );
return; // face is trivially trimmed
}
int fli, li, lti, ti;
// any knot scaling applied to the surface must also be applied to
// the parameter space trimming geometry
double xform[4][4]
= {{knot_scale[0][1], 0.0, 0.0, -knot_scale[0][0]*knot_scale[0][1] },
{0.0, knot_scale[1][1], 0.0, -knot_scale[1][0]*knot_scale[1][1] },
{0.0, 0.0, 1.0, 0.0},
{0.0, 0.0, 0.0, 1.0}};
// Add face's 2d trimming loop(s)
const int face_loop_count = face.m_li.Count();
for ( fli = 0; fli < face_loop_count; fli++ )
{
gluBeginTrim( nobj );
li = face.m_li[fli];
const ON_BrepLoop& loop = brep->m_L[li];
const int loop_trim_count = loop.m_ti.Count();
for ( lti = 0; lti < loop_trim_count; lti++ )
{
ti = loop.m_ti[lti];
const ON_BrepTrim& trim = brep->m_T[ti];
ON_GL( trim,
nobj,
GLU_MAP1_TRIM_2,
xform
);
}
gluEndTrim( nobj );
}
gluEndSurface( nobj );
}
}
void
SoNurbsSurface::GLRender(SoGLRenderAction *action)
//
////////////////////////////////////////////////////////////////////////
{
// First see if the object is visible and should be rendered now
if (! shouldGLRender(action))
return;
const SoCoordinateElement *ce =
SoCoordinateElement::getInstance(action->getState());
GLfloat *sKnots, *tKnots, *dstCoords;
GLenum type;
float *fKnots;
int32_t nCoords, uOffset, vOffset;
int32_t nsKnots, ntKnots, nsCoords, ntCoords;
int32_t nDstCoords;
int32_t sOffset, tOffset;
int i, j;
// Check for 0 control points
nCoords = ce->getNum();
if (nCoords == 0)
return;
// Make sure the first current material is sent to GL
SoMaterialBundle mb(action);
mb.sendFirst();
//
// Find the number of steps required for object space tessellation and
// the pixel tolerance used for screen space tessellation.
//
float val = SoComplexityElement::get(action->getState());
if (val < 0.0) val = 0.0;
if (val > 1.0) val = 1.0;
int steps;
if (val < 0.10) steps = 2;
else if (val < 0.25) steps = 3;
else if (val < 0.40) steps = 4;
else if (val < 0.55) steps = 5;
else steps = (int)(powf(val, 3.32)*28) + 2;
float pixTolerance = 104.0*val*val - 252.0*val + 150;
//
// If the surface is being cached, or if the tessellation is in object
// space, use the software NURBS library. Create a software NURBS
// rendering class and use it to make nurbs rendering calls. Since
// the software NURBS library generates triangles, texture mapping
// will happen automatically without having to render a separate
// texture surface.
//
if (SoComplexityTypeElement::get(action->getState()) ==
SoComplexityTypeElement::OBJECT_SPACE)
{
_SoNurbsGLRender *GLRender = new _SoNurbsGLRender();
//
// Set the sampling to be constant across the surface with the
// tessellation to be 'steps' across the S and T parameters
//
GLRender->setnurbsproperty( N_T2D, N_SAMPLINGMETHOD,
N_FIXEDRATE );
GLRender->setnurbsproperty( N_V3D, N_SAMPLINGMETHOD,
N_FIXEDRATE );
GLRender->setnurbsproperty( N_V3DR, N_SAMPLINGMETHOD,
N_FIXEDRATE );
GLRender->setnurbsproperty( N_T2D, N_S_STEPS, steps);
GLRender->setnurbsproperty( N_T2D, N_T_STEPS, steps);
GLRender->setnurbsproperty( N_V3D, N_S_STEPS, steps);
GLRender->setnurbsproperty( N_V3D, N_T_STEPS, steps);
GLRender->setnurbsproperty( N_V3DR, N_S_STEPS, steps);
GLRender->setnurbsproperty( N_V3DR, N_T_STEPS, steps);
// Determine whether a texture coordinate surface must be generated
SbBool doTextures = SoGLTextureEnabledElement::get(action->getState());
// Draw the surface
drawNURBS (GLRender, action->getState(), doTextures);
delete GLRender;
return;
}
if (SoDrawStyleElement::get(action->getState()) ==
SoDrawStyleElement::POINTS) {
//
// Render the control points of the surface. Rendering the points
// of the surface would be very slow, as the Software NURBS library
// would have to be used, and because of the view dependent
// tessellation, points would not necessarily remain visible.
//
glBegin(GL_POINTS);
if (ce->is3D()) {
for (i=0; i<nCoords; i++) {
const SbVec3f & coords3 = ce->get3((int)i);
glVertex3f ((GLfloat)(coords3[0]),
(GLfloat)(coords3[1]),
(GLfloat)(coords3[2]));
}
}
else {
for (i=0; i<nCoords; i++) {
const SbVec4f & coords4 = ce->get4((int)i);
glVertex4f ((GLfloat)(coords4[0]),
(GLfloat)(coords4[1]),
(GLfloat)(coords4[2]),
(GLfloat)(coords4[3]));
}
}
glEnd();
return;
}
//
// Render the NURBS surface using the GLU.
//
GLUnurbsObj *nurbsObj = gluNewNurbsRenderer();
switch (SoDrawStyleElement::get(action->getState())) {
case SoDrawStyleElement::FILLED:
gluNurbsProperty (nurbsObj, (GLenum)GLU_DISPLAY_MODE, GLU_FILL);
break;
case SoDrawStyleElement::LINES:
gluNurbsProperty (nurbsObj, (GLenum)GLU_DISPLAY_MODE, GLU_OUTLINE_POLYGON);
break;
}
gluNurbsProperty (nurbsObj, (GLenum)GLU_SAMPLING_TOLERANCE, (GLfloat)pixTolerance);
//
// Collect the control points and knot vectors into an array suitable
// for sending to the GL. The control points and knot vectors must be
// converted to double precision so that they can be passed to the
// GL NURBS routines.
//
GLfloat *dCoords, *duKnots, *dvKnots;
if (ce->is3D()) {
dCoords = (GLfloat *)new GLfloat[3*nCoords];
for (i=0; i<nCoords; i++) {
const SbVec3f &c3 = ce->get3((int)i);
dCoords[3*i] = (GLfloat)c3[0];
dCoords[3*i+1] = (GLfloat)c3[1];
dCoords[3*i+2] = (GLfloat)c3[2];
}
uOffset = 3;
type = GL_MAP2_VERTEX_3;
}
else {
dCoords = (GLfloat *)new GLfloat[4*nCoords];
for (i=0; i<nCoords; i++) {
const SbVec4f &c4 = ce->get4((int)i);
dCoords[4*i] = (GLfloat)c4[0];
dCoords[4*i+1] = (GLfloat)c4[1];
dCoords[4*i+2] = (GLfloat)c4[2];
dCoords[4*i+3] = (GLfloat)c4[3];
}
uOffset = 4;
type = GL_MAP2_VERTEX_4;
}
vOffset = uOffset * numUControlPoints.getValue();
fKnots = (float *)uKnotVector.getValues(0);
duKnots = (GLfloat *)new GLfloat[uKnotVector.getNum()];
for (i=0; i<uKnotVector.getNum(); i++)
duKnots[i] = (GLfloat)fKnots[i];
fKnots = (GLfloat *)vKnotVector.getValues(0);
dvKnots = (GLfloat *)new GLfloat[vKnotVector.getNum()];
for (i=0; i<vKnotVector.getNum(); i++)
dvKnots[i] = (GLfloat)fKnots[i];
// Texture mapping. If doTextures == TRUE
// we are drawing textures. If the textureCoordinateBinding is
// DEFAULT, we have to build a default NURBS surface for the texture
// coordinates, otherwise we use the texture coordinates in the texture
// element.
// If there is a software texture function defined, then we have to
// create a texture nurb surface with the same number of points and
// knots as the original surface, and call the texture coordinate function
// at each vertex.
SbBool doTextures = SoGLTextureEnabledElement::get(action->getState());
if(doTextures) {
switch (SoTextureCoordinateElement::getType(action->getState())) {
// software texture functions
case SoTextureCoordinateElement::FUNCTION:
{
// generate S and T coords from U and V coords
SbVec3f coord;
SbVec2f stCoord;
int offset;
SoTextureCoordinateBundle tb(action, TRUE);
nsCoords = numUControlPoints.getValue();
ntCoords = numVControlPoints.getValue();
sKnots = duKnots;
tKnots = dvKnots;
nsKnots = uKnotVector.getNum();
ntKnots = vKnotVector.getNum();
nDstCoords = nsCoords * ntCoords;
dstCoords = (GLfloat *)new GLfloat[nDstCoords * 2];
for(int v = 0; v < ntCoords; v++) {
for(int u = 0; u < nsCoords; u++) {
if (ce->is3D()) {
offset = 3 * (v * (int)nsCoords + u);
coord[0] = dCoords[offset + 0];
coord[1] = dCoords[offset + 1];
coord[2] = dCoords[offset + 2];
}
else {
offset = 4 * (v * (int)nsCoords + u);
coord[0] = dCoords[offset + 0] / dCoords[offset + 3];
coord[1] = dCoords[offset + 1] / dCoords[offset + 3];
coord[2] = dCoords[offset + 2] / dCoords[offset + 3];
}
const SbVec4f &tc = tb.get(coord, SbVec3f(0.0, 1.0, 0.0));
dstCoords[(v * (int)nsCoords + u) * 2 + 0] = tc[0];
dstCoords[(v * (int)nsCoords + u) * 2 + 1] = tc[1];
}
}
break;
}
// texture coordinates defined from texture node
case SoTextureCoordinateElement::EXPLICIT:
// get texture coordinates from texture node
const SoTextureCoordinateElement *te =
SoTextureCoordinateElement::getInstance(action->getState());
int32_t nstCoords = te->getNum();
if (nstCoords < 1) {
// Default texture coordinates are computed by defining
// a bezier surface that is defined in the same valid
// parameter space as the geometric surface. The valid
// parameter space is defined based on the order and knot
// vector. The coordinates go from 0 to one and the knot
// vectors span the valid range of the geometric surface.
// The knot vectors default to 0 and 1 in the event of bogus
// input data.
int uOrder, vOrder;
GLfloat sKnotVal1, sKnotVal2, tKnotVal1, tKnotVal2;
uOrder = uKnotVector.getNum() - numUControlPoints.getValue();
vOrder = vKnotVector.getNum() - numVControlPoints.getValue();
if ((uOrder > 0) && (uOrder < uKnotVector.getNum()))
sKnotVal1 = duKnots[uOrder-1];
else
sKnotVal1 = 0;
if ((uOrder > 0) && (uOrder < uKnotVector.getNum()))
sKnotVal2 = duKnots[uKnotVector.getNum()-uOrder];
else
sKnotVal2 = 1;
if ((vOrder > 0) && (vOrder < vKnotVector.getNum()))
tKnotVal1 = dvKnots[vOrder-1];
else
tKnotVal1 = 0;
if ((vOrder > 0) && (vOrder < vKnotVector.getNum()))
tKnotVal2 = dvKnots[vKnotVector.getNum()-vOrder];
else
tKnotVal2 = 1;
// do a linear 2x2 array
nsKnots = 4;
ntKnots = 4;
sKnots = (GLfloat *)new GLfloat[4];
tKnots = (GLfloat *)new GLfloat[4];
sKnots[0] = sKnots[1] = sKnotVal1;
tKnots[0] = tKnots[1] = tKnotVal1;
sKnots[2] = sKnots[3] = sKnotVal2;
tKnots[2] = tKnots[3] = tKnotVal2;
// allocate a 2 x 2 array of GLfloat[2]'s
nsCoords = 2;
ntCoords = 2;
nDstCoords = nsCoords * ntCoords * 2;
dstCoords = (GLfloat *)new GLfloat[nDstCoords];
for(i = 0; i < 2; i++) {
for(j = 0; j < 2; j++) {
dstCoords[(i * 2 + j) * 2 + 0] = j;
dstCoords[(i * 2 + j) * 2 + 1] = i;
}
}
}
else {
// get knot vectors from this node
nsKnots = sKnotVector.getNum();
fKnots = (float *)sKnotVector.getValues(0);
sKnots = (GLfloat *)new GLfloat[nsKnots];
for (i=0; i < nsKnots; i++)
sKnots[i] = (GLfloat)fKnots[i];
ntKnots = tKnotVector.getNum();
fKnots = (float *)tKnotVector.getValues(0);
tKnots = (GLfloat *)new GLfloat[ntKnots];
for (i=0; i < ntKnots; i++)
tKnots[i] = (GLfloat)fKnots[i];
nsCoords = numSControlPoints.getValue();
ntCoords = numTControlPoints.getValue();
nDstCoords = 2 * nstCoords;
dstCoords = (GLfloat *)new GLfloat[nDstCoords];
for(i = 0; i < nstCoords; i++) {
const SbVec2f &tc2 = te->get2(i);
dstCoords[2*i] = (GLfloat)tc2[0];
dstCoords[2*i+1] = (GLfloat)tc2[1];
}
}
break;
}
sOffset = 2;
tOffset = sOffset * nsCoords;
}
//
// Draw the NURBS surface. Begin the surface. Then load the texture
// map as a nurbs surface. Then, draw the geometric surface followed
// by all of its trim curves. Then, end the surface.
//
glEnable(GL_AUTO_NORMAL);
// Get one camera based element so that this node will be registered
// with the cache. If the camera changes, this element will cause
// the cache to be blown for this node and the nurbs surface will be
// regenerated.
SbMatrix vMat = SoViewingMatrixElement::get (action->getState());
SbMatrix mMat = SoModelMatrixElement::get (action->getState());
// Begin the surface.
gluBeginSurface(nurbsObj);
// Draw the texture surface
if(doTextures) {
// send down nurbs surface, then free memory
gluNurbsSurface(nurbsObj, (GLint)nsKnots, sKnots,
(GLint)ntKnots, tKnots,
(GLint)sOffset, (GLint)tOffset, dstCoords,
(GLint)(nsKnots - nsCoords),
(GLint)(ntKnots - ntCoords),
GL_MAP2_TEXTURE_COORD_2);
// delete knots if not sharing them with the surface description
// (in the case of software texture coordinates only)
if(sKnots != duKnots) {
delete [] sKnots;
delete [] tKnots;
}
delete [] dstCoords;
}
gluNurbsSurface (nurbsObj, (GLint)(uKnotVector.getNum()), duKnots,
(GLint)(vKnotVector.getNum()), dvKnots,
(GLint)uOffset, (GLint)vOffset, dCoords,
(GLint)(uKnotVector.getNum() -
numUControlPoints.getValue()),
(GLint)(vKnotVector.getNum() -
numVControlPoints.getValue()),
type);
//
// Get all of the trim curves and use them to trim the surface.
//
SoProfile *profile;
const SoNodeList &trimNodes = SoProfileElement::get(action->getState());
SbBool haveTrim = FALSE;
float *trimCoords, *trimKnots;
int32_t numTrimCoords, numKnots, offset;
int numTrims = trimNodes.getLength();
int floatsPerVec;
//
// For each trim curve, check its linkage to find out if it should be
// continued on to the previous trim curve or if it should begin a
// new trim curve. Then, send the trim to the NURBS library.
//
for (i=0; i<numTrims; i++)
{
GLfloat *dTrimCoords;
GLfloat *dtmp;
float *ftmp;
// Get the trim curve.
profile = (SoProfile *)trimNodes[(int) i];
profile->getTrimCurve (action->getState(), numTrimCoords,
trimCoords, floatsPerVec,
numKnots, trimKnots);
// Check for degenerate trim curves
if (numTrimCoords == 0)
continue;
// Check the linkage.
if ((profile->linkage.getValue() == SoProfileElement::START_FIRST) ||
(profile->linkage.getValue() == SoProfileElement::START_NEW))
{
if (haveTrim)
gluEndTrim(nurbsObj);
gluBeginTrim(nurbsObj);
haveTrim = TRUE;
}
// Set the data type of the control points to non-rational or rational
if (floatsPerVec == 2)
type = (GLenum)GLU_MAP1_TRIM_2;
else
type = (GLenum)GLU_MAP1_TRIM_3;
offset = floatsPerVec;
dTrimCoords = new GLfloat[numTrimCoords*floatsPerVec];
dtmp = dTrimCoords;
ftmp = trimCoords;
for (j=0; j<floatsPerVec*numTrimCoords; j++)
*dtmp++ = (GLfloat)(*ftmp++);
if (numKnots == 0)
{
// Send down a Piecewise Linear Trim Curve
gluPwlCurve (nurbsObj, (GLint)numTrimCoords, dTrimCoords,
(GLint)offset, type);
}
else
{
// Send down a NURBS Trim Curve
GLfloat *dTrimKnots = new GLfloat[numKnots];
dtmp = dTrimKnots;
ftmp = trimKnots;
for (j=0; j<numKnots; j++)
*dtmp++ = (GLfloat)(*ftmp++);
gluNurbsCurve (nurbsObj, (GLint)numKnots, dTrimKnots,
(GLint)offset, dTrimCoords,
(GLint)(numKnots - numTrimCoords), type);
delete[] dTrimKnots;
delete[] trimKnots;
}
delete[] dTrimCoords;
delete[] trimCoords;
}
if (haveTrim)
gluEndTrim(nurbsObj);
gluEndSurface(nurbsObj);
gluDeleteNurbsRenderer(nurbsObj);
glDisable(GL_AUTO_NORMAL);
delete[] dvKnots;
delete[] duKnots;
delete[] dCoords;
}
