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Small tweaks to CDT

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- added CDT support for demo
- added infinity-loop safety guard on CDT iteration count
- visit all 4 neighbours
- changed to options based API
This commit is contained in:
Mikko Mononen 2018-04-16 09:57:05 +03:00
parent c655ececd5
commit c6e6358018
5 changed files with 158 additions and 108 deletions
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81
Example/example.c
View file

@ -56,6 +56,7 @@ void poolFree( void* userData, void* ptr )
int run = 1; int run = 1;
int cdt = 0;
static void key(GLFWwindow* window, int key, int scancode, int action, int mods) static void key(GLFWwindow* window, int key, int scancode, int action, int mods)
{ {
@ -65,6 +66,8 @@ static void key(GLFWwindow* window, int key, int scancode, int action, int mods)
glfwSetWindowShouldClose(window, GL_TRUE); glfwSetWindowShouldClose(window, GL_TRUE);
if (key == GLFW_KEY_SPACE && action == GLFW_PRESS) if (key == GLFW_KEY_SPACE && action == GLFW_PRESS)
run = !run; run = !run;
if (key == GLFW_KEY_C && action == GLFW_PRESS)
cdt = !cdt;
} }
int main(int argc, char *argv[]) int main(int argc, char *argv[])
@ -79,14 +82,15 @@ int main(int argc, char *argv[])
float t = 0.0f, pt = 0.0f; float t = 0.0f, pt = 0.0f;
TESSalloc ma; TESSalloc ma;
TESStesselator* tess = 0; TESStesselator* tess = 0;
const int nvp = 6; const int nvp = 3;
unsigned char* vflags = 0; unsigned char* vflags = 0;
int nvflags = 0;
#ifdef USE_POOL #ifdef USE_POOL
struct MemPool pool; struct MemPool pool;
unsigned char mem[1024*1024]; unsigned char mem[1024*1024];
int nvflags = 0;
#else #else
int allocated = 0; int allocated = 0;
double t0 = 0, t1 = 0;
#endif #endif
TESS_NOTUSED(argc); TESS_NOTUSED(argc);
TESS_NOTUSED(argv); TESS_NOTUSED(argv);
@ -104,7 +108,7 @@ int main(int argc, char *argv[])
if (!fg) return -1; if (!fg) return -1;
printf("go...\n"); printf("go...\n");
// Flip y // Flip y
for (it = bg; it != NULL; it = it->next) for (it = bg; it != NULL; it = it->next)
for (i = 0; i < it->npts; ++i) for (i = 0; i < it->npts; ++i)
@ -138,7 +142,7 @@ int main(int argc, char *argv[])
it->pts[i*2+1] -= cy; it->pts[i*2+1] -= cy;
} }
} }
// Find BG bounds. // Find BG bounds.
bounds[0] = bounds[2] = bg->pts[0]; bounds[0] = bounds[2] = bg->pts[0];
bounds[1] = bounds[3] = bg->pts[1]; bounds[1] = bounds[3] = bg->pts[1];
@ -154,7 +158,7 @@ int main(int argc, char *argv[])
if (y > bounds[3]) bounds[3] = y; if (y > bounds[3]) bounds[3] = y;
} }
} }
#ifdef USE_POOL #ifdef USE_POOL
pool.size = 0; pool.size = 0;
@ -168,6 +172,8 @@ int main(int argc, char *argv[])
#else #else
t0 = glfwGetTime();
memset(&ma, 0, sizeof(ma)); memset(&ma, 0, sizeof(ma));
ma.memalloc = stdAlloc; ma.memalloc = stdAlloc;
ma.memfree = stdFree; ma.memfree = stdFree;
@ -178,6 +184,8 @@ int main(int argc, char *argv[])
if (!tess) if (!tess)
return -1; return -1;
tessSetOption(tess, TESS_CONSTRAINED_DELAUNAY_TRIANGULATION, 1);
// Offset the foreground shape to center of the bg. // Offset the foreground shape to center of the bg.
offx = (bounds[2]+bounds[0])/2; offx = (bounds[2]+bounds[0])/2;
offy = (bounds[3]+bounds[1])/2; offy = (bounds[3]+bounds[1])/2;
@ -189,7 +197,7 @@ int main(int argc, char *argv[])
it->pts[i*2+1] += offy; it->pts[i*2+1] += offy;
} }
} }
// Add contours. // Add contours.
for (it = bg; it != NULL; it = it->next) for (it = bg; it != NULL; it = it->next)
tessAddContour(tess, 2, it->pts, sizeof(float)*2, it->npts); tessAddContour(tess, 2, it->pts, sizeof(float)*2, it->npts);
@ -197,10 +205,14 @@ int main(int argc, char *argv[])
tessAddContour(tess, 2, it->pts, sizeof(float)*2, it->npts); tessAddContour(tess, 2, it->pts, sizeof(float)*2, it->npts);
if (!tessTesselate(tess, TESS_WINDING_POSITIVE, TESS_POLYGONS, nvp, 2, 0)) if (!tessTesselate(tess, TESS_WINDING_POSITIVE, TESS_POLYGONS, nvp, 2, 0))
return -1; return -1;
t1 = glfwGetTime();
printf("Time: %.3f ms\n", (t1 - t0) * 1000.0f);
printf("Memory used: %.1f kB\n", allocated/1024.0f); printf("Memory used: %.1f kB\n", allocated/1024.0f);
#endif #endif
mode = glfwGetVideoMode(glfwGetPrimaryMonitor()); mode = glfwGetVideoMode(glfwGetPrimaryMonitor());
width = mode->width - 40; width = mode->width - 40;
height = mode->height - 80; height = mode->height - 80;
@ -221,17 +233,27 @@ int main(int argc, char *argv[])
view[2] = cx + w*1.2f; view[2] = cx + w*1.2f;
view[1] = cy - w*1.2f*(float)height/(float)width; view[1] = cy - w*1.2f*(float)height/(float)width;
view[3] = cy + w*1.2f*(float)height/(float)width; view[3] = cy + w*1.2f*(float)height/(float)width;
glfwSetTime(0); glfwSetTime(0);
while (!glfwWindowShouldClose(window)) while (!glfwWindowShouldClose(window))
{ {
float ct = (float)glfwGetTime(); int winWidth, winHeight;
int fbWidth, fbHeight;
float pxr, ct;
glfwGetWindowSize(window, &winWidth, &winHeight);
glfwGetFramebufferSize(window, &fbWidth, &fbHeight);
// Calculate pixel ration for hi-dpi devices.
pxr = (float)fbWidth / (float)winWidth;
ct = (float)glfwGetTime();
if (run) t += ct - pt; if (run) t += ct - pt;
pt = ct; pt = ct;
// Update and render // Update and render
glViewport(0, 0, width, height); glViewport(0, 0, fbWidth, fbHeight);
glClearColor(0.3f, 0.3f, 0.32f, 1.0f); glClearColor(0.3f, 0.3f, 0.32f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT); glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glEnable(GL_BLEND); glEnable(GL_BLEND);
@ -251,9 +273,11 @@ int main(int argc, char *argv[])
tess = tessNewTess(&ma); tess = tessNewTess(&ma);
if (tess) if (tess)
{ {
tessSetOption(tess, TESS_CONSTRAINED_DELAUNAY_TRIANGULATION, cdt);
offx = (view[2]+view[0])/2 + sinf(t) * (view[2]-view[0])/2; offx = (view[2]+view[0])/2 + sinf(t) * (view[2]-view[0])/2;
offy = (view[3]+view[1])/2 + cosf(t*3.13f) * (view[3]-view[1])/6; offy = (view[3]+view[1])/2 + cosf(t*3.13f) * (view[3]-view[1])/6;
for (it = fg; it != NULL; it = it->next) for (it = fg; it != NULL; it = it->next)
{ {
for (i = 0; i < it->npts; ++i) for (i = 0; i < it->npts; ++i)
@ -293,7 +317,7 @@ int main(int argc, char *argv[])
nvflags = nverts; nvflags = nverts;
vflags = (unsigned char*)malloc(sizeof(unsigned char)*nvflags); vflags = (unsigned char*)malloc(sizeof(unsigned char)*nvflags);
} }
if (vflags) if (vflags)
{ {
// Vertex indices describe the order the indices were added and can be used // Vertex indices describe the order the indices were added and can be used
@ -303,7 +327,7 @@ int main(int argc, char *argv[])
for (i = 0; i < nverts; ++i) for (i = 0; i < nverts; ++i)
vflags[i] = vinds[i] == TESS_UNDEF ? 1 : 0; vflags[i] = vinds[i] == TESS_UNDEF ? 1 : 0;
} }
for (i = 0; i < nelems; ++i) for (i = 0; i < nelems; ++i)
{ {
int b = elems[i*2]; int b = elems[i*2];
@ -314,9 +338,9 @@ int main(int argc, char *argv[])
tess = 0; tess = 0;
} }
else else
tess = 0; tess = 0;
} }
#endif #endif
// Draw tesselated pieces. // Draw tesselated pieces.
if (tess) if (tess)
@ -326,7 +350,7 @@ int main(int argc, char *argv[])
const int* elems = tessGetElements(tess); const int* elems = tessGetElements(tess);
const int nverts = tessGetVertexCount(tess); const int nverts = tessGetVertexCount(tess);
const int nelems = tessGetElementCount(tess); const int nelems = tessGetElementCount(tess);
// Draw polygons. // Draw polygons.
glColor4ub(255,255,255,128); glColor4ub(255,255,255,128);
for (i = 0; i < nelems; ++i) for (i = 0; i < nelems; ++i)
@ -337,7 +361,10 @@ int main(int argc, char *argv[])
glVertex2f(verts[p[j]*2], verts[p[j]*2+1]); glVertex2f(verts[p[j]*2], verts[p[j]*2+1]);
glEnd(); glEnd();
} }
glLineWidth(1.0f * pxr);
glPointSize(3.0f * pxr);
glColor4ub(0,0,0,16); glColor4ub(0,0,0,16);
for (i = 0; i < nelems; ++i) for (i = 0; i < nelems; ++i)
{ {
@ -347,9 +374,8 @@ int main(int argc, char *argv[])
glVertex2f(verts[p[j]*2], verts[p[j]*2+1]); glVertex2f(verts[p[j]*2], verts[p[j]*2+1]);
glEnd(); glEnd();
} }
glColor4ub(0,0,0,128); glColor4ub(0,0,0,128);
glPointSize(3.0f);
glBegin(GL_POINTS); glBegin(GL_POINTS);
for (i = 0; i < nverts; ++i) for (i = 0; i < nverts; ++i)
{ {
@ -360,21 +386,22 @@ int main(int argc, char *argv[])
glVertex2f(verts[i*2], verts[i*2+1]); glVertex2f(verts[i*2], verts[i*2+1]);
} }
glEnd(); glEnd();
glPointSize(1.0f); glPointSize(1.0f);
} }
glEnable(GL_DEPTH_TEST); glEnable(GL_DEPTH_TEST);
glfwSwapBuffers(window); glfwSwapBuffers(window);
glfwPollEvents(); glfwPollEvents();
} }
if (tess) tessDeleteTess(tess); if (tess) tessDeleteTess(tess);
if (vflags) if (vflags)
free(vflags); free(vflags);
svgDelete(bg); svgDelete(bg);
svgDelete(fg); svgDelete(fg);
glfwTerminate(); glfwTerminate();
return 0; return 0;

37
Include/tesselator.h
View file

@ -1,5 +1,5 @@
/* /*
** SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008) ** SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
** Copyright (C) [dates of first publication] Silicon Graphics, Inc. ** Copyright (C) [dates of first publication] Silicon Graphics, Inc.
** All Rights Reserved. ** All Rights Reserved.
** **
@ -9,10 +9,10 @@
** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies ** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
** of the Software, and to permit persons to whom the Software is furnished to do so, ** of the Software, and to permit persons to whom the Software is furnished to do so,
** subject to the following conditions: ** subject to the following conditions:
** **
** The above copyright notice including the dates of first publication and either this ** The above copyright notice including the dates of first publication and either this
** permission notice or a reference to http://oss.sgi.com/projects/FreeB/ shall be ** permission notice or a reference to http://oss.sgi.com/projects/FreeB/ shall be
** included in all copies or substantial portions of the Software. ** included in all copies or substantial portions of the Software.
** **
** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, ** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
** INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A ** INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
@ -20,7 +20,7 @@
** BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, ** BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE ** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
** OR OTHER DEALINGS IN THE SOFTWARE. ** OR OTHER DEALINGS IN THE SOFTWARE.
** **
** Except as contained in this notice, the name of Silicon Graphics, Inc. shall not ** Except as contained in this notice, the name of Silicon Graphics, Inc. shall not
** be used in advertising or otherwise to promote the sale, use or other dealings in ** be used in advertising or otherwise to promote the sale, use or other dealings in
** this Software without prior written authorization from Silicon Graphics, Inc. ** this Software without prior written authorization from Silicon Graphics, Inc.
@ -106,17 +106,22 @@ enum TessWindingRule
// } // }
// glEnd(); // glEnd();
// } // }
//
// TESS_CONSTRAINED_DELAUNAY_TRIANGLES
// Similar to TESS_POLYGONS, but we output only triangles and we attempt to provide a valid
// Constrained Delaunay triangulation.
enum TessElementType enum TessElementType
{ {
TESS_POLYGONS, TESS_POLYGONS,
TESS_CONNECTED_POLYGONS, TESS_CONNECTED_POLYGONS,
TESS_BOUNDARY_CONTOURS, TESS_BOUNDARY_CONTOURS,
TESS_CONSTRAINED_DELAUNAY_TRIANGLES };
// TESS_CONSTRAINED_DELAUNAY_TRIANGULATION
// If enabled, the initial triagulation is improved with non-robust Constrained Delayney triangulation.
// Disable by default.
enum TessOption
{
TESS_CONSTRAINED_DELAUNAY_TRIANGULATION,
}; };
typedef float TESSreal; typedef float TESSreal;
@ -138,12 +143,12 @@ typedef struct TESSalloc TESSalloc;
// how often to allocate memory from the system versus how much extra space the system // how often to allocate memory from the system versus how much extra space the system
// should allocate. Reasonable defaults are show in commects below, they will be used if // should allocate. Reasonable defaults are show in commects below, they will be used if
// the bucket sizes are zero. // the bucket sizes are zero.
// //
// The use may left the memrealloc to be null. In that case, the tesselator will not try to // The use may left the memrealloc to be null. In that case, the tesselator will not try to
// dynamically grow int's internal arrays. The tesselator only needs the reallocation when it // dynamically grow int's internal arrays. The tesselator only needs the reallocation when it
// has found intersecting segments and needs to add new vertex. This defency can be cured by // has found intersecting segments and needs to add new vertex. This defency can be cured by
// allocating some extra vertices beforehand. The 'extraVertices' variable allows to specify // allocating some extra vertices beforehand. The 'extraVertices' variable allows to specify
// number of expected extra vertices. // number of expected extra vertices.
struct TESSalloc struct TESSalloc
{ {
void *(*memalloc)( void *userData, unsigned int size ); void *(*memalloc)( void *userData, unsigned int size );
@ -189,12 +194,18 @@ void tessDeleteTess( TESStesselator *tess );
// count - number of vertices in contour. // count - number of vertices in contour.
void tessAddContour( TESStesselator *tess, int size, const void* pointer, int stride, int count ); void tessAddContour( TESStesselator *tess, int size, const void* pointer, int stride, int count );
// tessSetOption() - Toggles optional tessellation parameters
// Parameters:
// option - one of TessOption
// value - 1 if enabled, 0 if disabled.
void tessSetOption( TESStesselator *tess, int option, int value );
// tessTesselate() - tesselate contours. // tessTesselate() - tesselate contours.
// Parameters: // Parameters:
// tess - pointer to tesselator object. // tess - pointer to tesselator object.
// windingRule - winding rules used for tesselation, must be one of TessWindingRule. // windingRule - winding rules used for tesselation, must be one of TessWindingRule.
// elementType - defines the tesselation result element type, must be one of TessElementType. // elementType - defines the tesselation result element type, must be one of TessElementType.
// polySize - defines maximum vertices per polygons if output is polygons. If elementType is TESS_CONSTRAINED_DELAUNAY_TRIANGLES, this parameter is ignored. // polySize - defines maximum vertices per polygons if output is polygons.
// vertexSize - defines the number of coordinates in tesselation result vertex, must be 2 or 3. // vertexSize - defines the number of coordinates in tesselation result vertex, must be 2 or 3.
// normal - defines the normal of the input contours, of null the normal is calculated automatically. // normal - defines the normal of the input contours, of null the normal is calculated automatically.
// Returns: // Returns:
@ -212,7 +223,7 @@ const TESSreal* tessGetVertices( TESStesselator *tess );
// Every point added using tessAddContour() will get a new index starting at 0. // Every point added using tessAddContour() will get a new index starting at 0.
// New vertices generated at the intersections of segments are assigned value TESS_UNDEF. // New vertices generated at the intersections of segments are assigned value TESS_UNDEF.
const TESSindex* tessGetVertexIndices( TESStesselator *tess ); const TESSindex* tessGetVertexIndices( TESStesselator *tess );
// tessGetElementCount() - Returns number of elements in the the tesselated output. // tessGetElementCount() - Returns number of elements in the the tesselated output.
int tessGetElementCount( TESStesselator *tess ); int tessGetElementCount( TESStesselator *tess );

27
Source/geom.c
View file

@ -1,5 +1,5 @@
/* /*
** SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008) ** SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
** Copyright (C) [dates of first publication] Silicon Graphics, Inc. ** Copyright (C) [dates of first publication] Silicon Graphics, Inc.
** All Rights Reserved. ** All Rights Reserved.
** **
@ -9,10 +9,10 @@
** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies ** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
** of the Software, and to permit persons to whom the Software is furnished to do so, ** of the Software, and to permit persons to whom the Software is furnished to do so,
** subject to the following conditions: ** subject to the following conditions:
** **
** The above copyright notice including the dates of first publication and either this ** The above copyright notice including the dates of first publication and either this
** permission notice or a reference to http://oss.sgi.com/projects/FreeB/ shall be ** permission notice or a reference to http://oss.sgi.com/projects/FreeB/ shall be
** included in all copies or substantial portions of the Software. ** included in all copies or substantial portions of the Software.
** **
** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, ** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
** INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A ** INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
@ -20,7 +20,7 @@
** BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, ** BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE ** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
** OR OTHER DEALINGS IN THE SOFTWARE. ** OR OTHER DEALINGS IN THE SOFTWARE.
** **
** Except as contained in this notice, the name of Silicon Graphics, Inc. shall not ** Except as contained in this notice, the name of Silicon Graphics, Inc. shall not
** be used in advertising or otherwise to promote the sale, use or other dealings in ** be used in advertising or otherwise to promote the sale, use or other dealings in
** this Software without prior written authorization from Silicon Graphics, Inc. ** this Software without prior written authorization from Silicon Graphics, Inc.
@ -266,16 +266,13 @@ void tesedgeIntersect( TESSvertex *o1, TESSvertex *d1,
*/ */
TESSreal calcAngle( TESSvertex *v0, TESSvertex *v1, TESSvertex *v2 ) TESSreal calcAngle( TESSvertex *v0, TESSvertex *v1, TESSvertex *v2 )
{ {
TESSreal num; TESSreal num, den, ax, ay, bx, by;
TESSreal den; ax = v2->s - v1->s;
TESSreal a[2]; ay = v2->t - v1->t;
TESSreal b[2]; bx = v0->s - v1->s;
a[0] = v2->s - v1->s; by = v0->t - v1->t;
a[1] = v2->t - v1->t; num = ax * bx + ay * by;
b[0] = v0->s - v1->s; den = sqrt( ax * ax + ay * ay ) * sqrt( bx * bx + by * by );
b[1] = v0->t - v1->t;
num = a[0] * b[0] + a[1] * b[1];
den = sqrt( a[0] * a[0] + a[1] * a[1] ) * sqrt( b[0] * b[0] + b[1] * b[1] );
if ( den > 0.0 ) num /= den; if ( den > 0.0 ) num /= den;
if ( num < -1.0 ) num = -1.0; if ( num < -1.0 ) num = -1.0;
if ( num > 1.0 ) num = 1.0; if ( num > 1.0 ) num = 1.0;
@ -288,5 +285,5 @@ TESSreal calcAngle( TESSvertex *v0, TESSvertex *v1, TESSvertex *v2 )
int tesedgeIsLocallyDelaunay( TESShalfEdge *e ) int tesedgeIsLocallyDelaunay( TESShalfEdge *e )
{ {
return (calcAngle(e->Lnext->Org, e->Lnext->Lnext->Org, e->Org) + return (calcAngle(e->Lnext->Org, e->Lnext->Lnext->Org, e->Org) +
calcAngle(e->Sym->Lnext->Org, e->Sym->Lnext->Lnext->Org, e->Sym->Org)) < (M_PI + 0.01); calcAngle(e->Sym->Lnext->Org, e->Sym->Lnext->Lnext->Org, e->Sym->Org)) < (M_PI + 0.01);
} }

107
Source/tess.c
View file

@ -1,5 +1,5 @@
/* /*
** SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008) ** SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
** Copyright (C) [dates of first publication] Silicon Graphics, Inc. ** Copyright (C) [dates of first publication] Silicon Graphics, Inc.
** All Rights Reserved. ** All Rights Reserved.
** **
@ -9,10 +9,10 @@
** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies ** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
** of the Software, and to permit persons to whom the Software is furnished to do so, ** of the Software, and to permit persons to whom the Software is furnished to do so,
** subject to the following conditions: ** subject to the following conditions:
** **
** The above copyright notice including the dates of first publication and either this ** The above copyright notice including the dates of first publication and either this
** permission notice or a reference to http://oss.sgi.com/projects/FreeB/ shall be ** permission notice or a reference to http://oss.sgi.com/projects/FreeB/ shall be
** included in all copies or substantial portions of the Software. ** included in all copies or substantial portions of the Software.
** **
** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, ** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
** INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A ** INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
@ -20,7 +20,7 @@
** BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, ** BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE ** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
** OR OTHER DEALINGS IN THE SOFTWARE. ** OR OTHER DEALINGS IN THE SOFTWARE.
** **
** Except as contained in this notice, the name of Silicon Graphics, Inc. shall not ** Except as contained in this notice, the name of Silicon Graphics, Inc. shall not
** be used in advertising or otherwise to promote the sale, use or other dealings in ** be used in advertising or otherwise to promote the sale, use or other dealings in
** this Software without prior written authorization from Silicon Graphics, Inc. ** this Software without prior written authorization from Silicon Graphics, Inc.
@ -177,7 +177,7 @@ extern int RandomSweep;
#define S_UNIT_X (RandomSweep ? (2*drand48()-1) : 1.0) #define S_UNIT_X (RandomSweep ? (2*drand48()-1) : 1.0)
#define S_UNIT_Y (RandomSweep ? (2*drand48()-1) : 0.0) #define S_UNIT_Y (RandomSweep ? (2*drand48()-1) : 0.0)
#else #else
#if defined(SLANTED_SWEEP) #if defined(SLANTED_SWEEP)
/* The "feature merging" is not intended to be complete. There are /* The "feature merging" is not intended to be complete. There are
* special cases where edges are nearly parallel to the sweep line * special cases where edges are nearly parallel to the sweep line
* which are not implemented. The algorithm should still behave * which are not implemented. The algorithm should still behave
@ -286,7 +286,7 @@ void tessProjectPolygon( TESStesselator *tess )
* (what else would it do??) The region must consist of a single * (what else would it do??) The region must consist of a single
* loop of half-edges (see mesh.h) oriented CCW. "Monotone" in this * loop of half-edges (see mesh.h) oriented CCW. "Monotone" in this
* case means that any vertical line intersects the interior of the * case means that any vertical line intersects the interior of the
* region in a single interval. * region in a single interval.
* *
* Tessellation consists of adding interior edges (actually pairs of * Tessellation consists of adding interior edges (actually pairs of
* half-edges), to split the region into non-overlapping triangles. * half-edges), to split the region into non-overlapping triangles.
@ -436,43 +436,49 @@ TESShalfEdge *stackPop( EdgeStack *stack )
return e; return e;
} }
/*
Starting with a valid triangulation, uses the Edge Flip algorithm to
refine the triangulation into a Constrained Delaunay Triangulation.
*/
int tessMeshRefineDelaunay( TESSmesh *mesh, TESSalloc *alloc )
{
/* At this point, we have a valid, but not optimal, triangulation.
We refine the triangulation using the Edge Flip algorithm */
/* // Starting with a valid triangulation, uses the Edge Flip algorithm to
1) Find all internal edges // refine the triangulation into a Constrained Delaunay Triangulation.
2) Mark all dual edges void tessMeshRefineDelaunay( TESSmesh *mesh, TESSalloc *alloc )
3) insert all dual edges into a queue {
*/ // At this point, we have a valid, but not optimal, triangulation.
// We refine the triangulation using the Edge Flip algorithm
//
// 1) Find all internal edges
// 2) Mark all dual edges
// 3) insert all dual edges into a queue
TESSface *f; TESSface *f;
EdgeStack stack; EdgeStack stack;
TESShalfEdge *e; TESShalfEdge *e;
TESShalfEdge *edges[4]; int maxFaces = 0, maxIter = 0, iter = 0;
stackInit(&stack, alloc); stackInit(&stack, alloc);
for( f = mesh->fHead.next; f != &mesh->fHead; f = f->next ) { for( f = mesh->fHead.next; f != &mesh->fHead; f = f->next ) {
if ( f->inside) { if ( f->inside) {
e = f->anEdge; e = f->anEdge;
do { do {
e->mark = EdgeIsInternal(e); /* Mark internal edges */ e->mark = EdgeIsInternal(e); // Mark internal edges
if (e->mark && !e->Sym->mark) stackPush(&stack, e); /* Insert into queue */ if (e->mark && !e->Sym->mark) stackPush(&stack, e); // Insert into queue
e = e->Lnext; e = e->Lnext;
} while (e != f->anEdge); } while (e != f->anEdge);
maxFaces++;
} }
} }
// The algorithm should converge on O(n^2), since the predicate is not robust,
// we'll save guard against infinite loop.
maxIter = maxFaces * maxFaces;
// Pop stack until we find a reversed edge // Pop stack until we find a reversed edge
// Flip the reversed edge, and insert any of the four opposite edges // Flip the reversed edge, and insert any of the four opposite edges
// which are internal and not already in the stack (!marked) // which are internal and not already in the stack (!marked)
while (!stackEmpty(&stack)) { while (!stackEmpty(&stack) && iter < maxIter) {
e = stackPop(&stack); e = stackPop(&stack);
e->mark = e->Sym->mark = 0; e->mark = e->Sym->mark = 0;
if (!tesedgeIsLocallyDelaunay(e)) { if (!tesedgeIsLocallyDelaunay(e)) {
TESShalfEdge *edges[4];
int i; int i;
tessMeshFlipEdge(mesh, e); tessMeshFlipEdge(mesh, e);
// for each opposite edge // for each opposite edge
@ -480,18 +486,17 @@ int tessMeshRefineDelaunay( TESSmesh *mesh, TESSalloc *alloc )
edges[1] = e->Lprev; edges[1] = e->Lprev;
edges[2] = e->Sym->Lnext; edges[2] = e->Sym->Lnext;
edges[3] = e->Sym->Lprev; edges[3] = e->Sym->Lprev;
for (i=0;i<3;i++) { for (i = 0; i < 4; i++) {
if (!edges[i]->mark && EdgeIsInternal(edges[i])) { if (!edges[i]->mark && EdgeIsInternal(edges[i])) {
edges[i]->mark = edges[i]->Sym->mark = 1; edges[i]->mark = edges[i]->Sym->mark = 1;
stackPush(&stack, edges[i]); stackPush(&stack, edges[i]);
} }
} }
} }
iter++;
} }
stackDelete(&stack);
return 1; stackDelete(&stack);
} }
@ -584,7 +589,7 @@ TESStesselator* tessNewTess( TESSalloc* alloc )
if (alloc == NULL) if (alloc == NULL)
alloc = &defaulAlloc; alloc = &defaulAlloc;
/* Only initialize fields which can be changed by the api. Other fields /* Only initialize fields which can be changed by the api. Other fields
* are initialized where they are used. * are initialized where they are used.
*/ */
@ -605,7 +610,7 @@ TESStesselator* tessNewTess( TESSalloc* alloc )
tess->alloc.dictNodeBucketSize = 512; tess->alloc.dictNodeBucketSize = 512;
if (tess->alloc.regionBucketSize == 0) if (tess->alloc.regionBucketSize == 0)
tess->alloc.regionBucketSize = 256; tess->alloc.regionBucketSize = 256;
tess->normal[0] = 0; tess->normal[0] = 0;
tess->normal[1] = 0; tess->normal[1] = 0;
tess->normal[2] = 0; tess->normal[2] = 0;
@ -629,7 +634,7 @@ TESStesselator* tessNewTess( TESSalloc* alloc )
tess->outOfMemory = 0; tess->outOfMemory = 0;
tess->vertexIndexCounter = 0; tess->vertexIndexCounter = 0;
tess->vertices = 0; tess->vertices = 0;
tess->vertexIndices = 0; tess->vertexIndices = 0;
tess->vertexCount = 0; tess->vertexCount = 0;
@ -641,9 +646,9 @@ TESStesselator* tessNewTess( TESSalloc* alloc )
void tessDeleteTess( TESStesselator *tess ) void tessDeleteTess( TESStesselator *tess )
{ {
struct TESSalloc alloc = tess->alloc; struct TESSalloc alloc = tess->alloc;
deleteBucketAlloc( tess->regionPool ); deleteBucketAlloc( tess->regionPool );
if( tess->mesh != NULL ) { if( tess->mesh != NULL ) {
@ -722,7 +727,7 @@ void OutputPolymesh( TESStesselator *tess, TESSmesh *mesh, int elementType, int
edge = edge->Lnext; edge = edge->Lnext;
} }
while (edge != f->anEdge); while (edge != f->anEdge);
assert( faceVerts <= polySize ); assert( faceVerts <= polySize );
f->n = maxFaceCount; f->n = maxFaceCount;
@ -739,7 +744,7 @@ void OutputPolymesh( TESStesselator *tess, TESSmesh *mesh, int elementType, int
tess->outOfMemory = 1; tess->outOfMemory = 1;
return; return;
} }
tess->vertexCount = maxVertexCount; tess->vertexCount = maxVertexCount;
tess->vertices = (TESSreal*)tess->alloc.memalloc( tess->alloc.userData, tess->vertices = (TESSreal*)tess->alloc.memalloc( tess->alloc.userData,
sizeof(TESSreal) * tess->vertexCount * vertexSize ); sizeof(TESSreal) * tess->vertexCount * vertexSize );
@ -756,7 +761,7 @@ void OutputPolymesh( TESStesselator *tess, TESSmesh *mesh, int elementType, int
tess->outOfMemory = 1; tess->outOfMemory = 1;
return; return;
} }
// Output vertices. // Output vertices.
for ( v = mesh->vHead.next; v != &mesh->vHead; v = v->next ) for ( v = mesh->vHead.next; v != &mesh->vHead; v = v->next )
{ {
@ -778,7 +783,7 @@ void OutputPolymesh( TESStesselator *tess, TESSmesh *mesh, int elementType, int
for ( f = mesh->fHead.next; f != &mesh->fHead; f = f->next ) for ( f = mesh->fHead.next; f != &mesh->fHead; f = f->next )
{ {
if ( !f->inside ) continue; if ( !f->inside ) continue;
// Store polygon // Store polygon
edge = f->anEdge; edge = f->anEdge;
faceVerts = 0; faceVerts = 0;
@ -847,7 +852,7 @@ void OutputContours( TESStesselator *tess, TESSmesh *mesh, int vertexSize )
tess->outOfMemory = 1; tess->outOfMemory = 1;
return; return;
} }
tess->vertices = (TESSreal*)tess->alloc.memalloc( tess->alloc.userData, tess->vertices = (TESSreal*)tess->alloc.memalloc( tess->alloc.userData,
sizeof(TESSreal) * tess->vertexCount * vertexSize ); sizeof(TESSreal) * tess->vertexCount * vertexSize );
if (!tess->vertices) if (!tess->vertices)
@ -863,7 +868,7 @@ void OutputContours( TESStesselator *tess, TESSmesh *mesh, int vertexSize )
tess->outOfMemory = 1; tess->outOfMemory = 1;
return; return;
} }
verts = tess->vertices; verts = tess->vertices;
elements = tess->elements; elements = tess->elements;
vertInds = tess->vertexIndices; vertInds = tess->vertexIndices;
@ -964,6 +969,17 @@ void tessAddContour( TESStesselator *tess, int size, const void* vertices,
} }
} }
void tessSetOption( TESStesselator *tess, int option, int value )
{
switch(option)
{
case TESS_CONSTRAINED_DELAUNAY_TRIANGULATION:
tess->processCDT = value > 0 ? 1 : 0;
break;
}
}
int tessTesselate( TESStesselator *tess, int windingRule, int elementType, int tessTesselate( TESStesselator *tess, int windingRule, int elementType,
int polySize, int vertexSize, const TESSreal* normal ) int polySize, int vertexSize, const TESSreal* normal )
{ {
@ -984,7 +1000,7 @@ int tessTesselate( TESStesselator *tess, int windingRule, int elementType,
} }
tess->vertexIndexCounter = 0; tess->vertexIndexCounter = 0;
if (normal) if (normal)
{ {
tess->normal[0] = normal[0]; tess->normal[0] = normal[0];
@ -999,7 +1015,7 @@ int tessTesselate( TESStesselator *tess, int windingRule, int elementType,
if (vertexSize > 3) if (vertexSize > 3)
vertexSize = 3; vertexSize = 3;
if (setjmp(tess->env) != 0) { if (setjmp(tess->env) != 0) {
/* come back here if out of memory */ /* come back here if out of memory */
return 0; return 0;
} }
@ -1033,12 +1049,9 @@ int tessTesselate( TESStesselator *tess, int windingRule, int elementType,
if (elementType == TESS_BOUNDARY_CONTOURS) { if (elementType == TESS_BOUNDARY_CONTOURS) {
rc = tessMeshSetWindingNumber( mesh, 1, TRUE ); rc = tessMeshSetWindingNumber( mesh, 1, TRUE );
} else { } else {
rc = tessMeshTessellateInterior( mesh ); rc = tessMeshTessellateInterior( mesh );
if (elementType == TESS_CONSTRAINED_DELAUNAY_TRIANGLES) { if (rc != 0 && tess->processCDT != 0)
rc = tessMeshRefineDelaunay( mesh, &tess->alloc ); tessMeshRefineDelaunay( mesh, &tess->alloc );
elementType = TESS_POLYGONS;
polySize = 3;
}
} }
if (rc == 0) longjmp(tess->env,1); /* could've used a label */ if (rc == 0) longjmp(tess->env,1); /* could've used a label */

14
Source/tess.h
View file

@ -1,5 +1,5 @@
/* /*
** SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008) ** SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
** Copyright (C) [dates of first publication] Silicon Graphics, Inc. ** Copyright (C) [dates of first publication] Silicon Graphics, Inc.
** All Rights Reserved. ** All Rights Reserved.
** **
@ -9,10 +9,10 @@
** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies ** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
** of the Software, and to permit persons to whom the Software is furnished to do so, ** of the Software, and to permit persons to whom the Software is furnished to do so,
** subject to the following conditions: ** subject to the following conditions:
** **
** The above copyright notice including the dates of first publication and either this ** The above copyright notice including the dates of first publication and either this
** permission notice or a reference to http://oss.sgi.com/projects/FreeB/ shall be ** permission notice or a reference to http://oss.sgi.com/projects/FreeB/ shall be
** included in all copies or substantial portions of the Software. ** included in all copies or substantial portions of the Software.
** **
** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, ** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
** INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A ** INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
@ -20,7 +20,7 @@
** BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, ** BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE ** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
** OR OTHER DEALINGS IN THE SOFTWARE. ** OR OTHER DEALINGS IN THE SOFTWARE.
** **
** Except as contained in this notice, the name of Silicon Graphics, Inc. shall not ** Except as contained in this notice, the name of Silicon Graphics, Inc. shall not
** be used in advertising or otherwise to promote the sale, use or other dealings in ** be used in advertising or otherwise to promote the sale, use or other dealings in
** this Software without prior written authorization from Silicon Graphics, Inc. ** this Software without prior written authorization from Silicon Graphics, Inc.
@ -61,6 +61,8 @@ struct TESStesselator {
TESSreal bmin[2]; TESSreal bmin[2];
TESSreal bmax[2]; TESSreal bmax[2];
int processCDT; /* option to run Constrained Delayney pass. */
/*** state needed for the line sweep ***/ /*** state needed for the line sweep ***/
int windingRule; /* rule for determining polygon interior */ int windingRule; /* rule for determining polygon interior */
@ -71,7 +73,7 @@ struct TESStesselator {
struct BucketAlloc* regionPool; struct BucketAlloc* regionPool;
TESSindex vertexIndexCounter; TESSindex vertexIndexCounter;
TESSreal *vertices; TESSreal *vertices;
TESSindex *vertexIndices; TESSindex *vertexIndices;
int vertexCount; int vertexCount;
@ -79,7 +81,7 @@ struct TESStesselator {
int elementCount; int elementCount;
TESSalloc alloc; TESSalloc alloc;
jmp_buf env; /* place to jump to when memAllocs fail */ jmp_buf env; /* place to jump to when memAllocs fail */
}; };