X-Git-Url: http://git.xonotic.org/?a=blobdiff_plain;f=polygon.c;h=2bc897fbe8baec206093b5fe6bb26308b1a15793;hb=ac8abfb4850b0061611141880dbff840a2e705bc;hp=8133dce3dbd0e99d26dbf705a0b63498c723b12c;hpb=2824a71dcb6cb3568f87b9a3dae340c342865669;p=xonotic%2Fdarkplaces.git

diff --git a/polygon.c b/polygon.c
index 8133dce3..2bc897fb 100644
--- a/polygon.c
+++ b/polygon.c
@@ -9,7 +9,7 @@ Polygon clipping routines written by Forest Hale and placed into public domain.
 void PolygonF_QuadForPlane(float *outpoints, float planenormalx, float planenormaly, float planenormalz, float planedist, float quadsize)
 {
 	float d, quadright[3], quadup[3];
-	if (planenormalz > planenormalx && planenormalz > planenormaly)
+	if (fabs(planenormalz) > fabs(planenormalx) && fabs(planenormalz) > fabs(planenormaly))
 	{
 		quadup[0] = 1;
 		quadup[1] = 0;
@@ -25,10 +25,10 @@ void PolygonF_QuadForPlane(float *outpoints, float planenormalx, float planenorm
 	d = -(quadup[0] * planenormalx + quadup[1] * planenormaly + quadup[2] * planenormalz);
 	// VectorMA(quadup, d, planenormal, quadup);
 	quadup[0] += d * planenormalx;
-	quadup[1] += d * planenormalx;
-	quadup[2] += d * planenormalx;
+	quadup[1] += d * planenormaly;
+	quadup[2] += d * planenormalz;
 	// VectorNormalize(quadup);
-	d = 1.0 / sqrt(quadup[0] * quadup[0] + quadup[1] * quadup[1] + quadup[2] * quadup[2]);
+	d = (float)(1.0 / sqrt(quadup[0] * quadup[0] + quadup[1] * quadup[1] + quadup[2] * quadup[2]));
 	quadup[0] *= d;
 	quadup[1] *= d;
 	quadup[2] *= d;
@@ -54,7 +54,7 @@ void PolygonF_QuadForPlane(float *outpoints, float planenormalx, float planenorm
 void PolygonD_QuadForPlane(double *outpoints, double planenormalx, double planenormaly, double planenormalz, double planedist, double quadsize)
 {
 	double d, quadright[3], quadup[3];
-	if (planenormalz > planenormalx && planenormalz > planenormaly)
+	if (fabs(planenormalz) > fabs(planenormalx) && fabs(planenormalz) > fabs(planenormaly))
 	{
 		quadup[0] = 1;
 		quadup[1] = 0;
@@ -70,8 +70,8 @@ void PolygonD_QuadForPlane(double *outpoints, double planenormalx, double planen
 	d = -(quadup[0] * planenormalx + quadup[1] * planenormaly + quadup[2] * planenormalz);
 	// VectorMA(quadup, d, planenormal, quadup);
 	quadup[0] += d * planenormalx;
-	quadup[1] += d * planenormalx;
-	quadup[2] += d * planenormalx;
+	quadup[1] += d * planenormaly;
+	quadup[2] += d * planenormalz;
 	// VectorNormalize(quadup);
 	d = 1.0 / sqrt(quadup[0] * quadup[0] + quadup[1] * quadup[1] + quadup[2] * quadup[2]);
 	quadup[0] *= d;
@@ -96,21 +96,21 @@ void PolygonD_QuadForPlane(double *outpoints, double planenormalx, double planen
 	outpoints[11] = planedist * planenormalz - quadsize * quadright[2] - quadsize * quadup[2];
 }
 
-void PolygonF_Divide(unsigned int innumpoints, const float *inpoints, float planenormalx, float planenormaly, float planenormalz, float planedist, float epsilon, unsigned int outfrontmaxpoints, float *outfrontpoints, unsigned int *neededfrontpoints, unsigned int outbackmaxpoints, float *outbackpoints, unsigned int *neededbackpoints)
+void PolygonF_Divide(int innumpoints, const float *inpoints, float planenormalx, float planenormaly, float planenormalz, float planedist, float epsilon, int outfrontmaxpoints, float *outfrontpoints, int *neededfrontpoints, int outbackmaxpoints, float *outbackpoints, int *neededbackpoints, int *oncountpointer)
 {
-	unsigned int i, frontcount, backcount;
+	int i, frontcount = 0, backcount = 0, oncount = 0;
 	const float *n, *p;
-	float frac, pdist, ndist;
-	frontcount = 0;
-	backcount = 0;
-	p = inpoints + (innumpoints - 1) * 3;
-	n = inpoints;
-	pdist = p[0] * planenormalx + p[1] * planenormaly + p[2] * planenormalz - planedist;
+	double frac, pdist, ndist;
 	for (i = 0;i < innumpoints;i++)
 	{
+		p = inpoints + i * 3;
+		n = inpoints + ((i + 1) < innumpoints ? (i + 1) : 0) * 3;
+		pdist = p[0] * planenormalx + p[1] * planenormaly + p[2] * planenormalz - planedist;
 		ndist = n[0] * planenormalx + n[1] * planenormaly + n[2] * planenormalz - planedist;
 		if (pdist >= -epsilon)
 		{
+			if (pdist <= epsilon)
+				oncount++;
 			if (frontcount < outfrontmaxpoints)
 			{
 				*outfrontpoints++ = p[0];
@@ -131,47 +131,47 @@ void PolygonF_Divide(unsigned int innumpoints, const float *inpoints, float plan
 		}
 		if ((pdist > epsilon && ndist < -epsilon) || (pdist < -epsilon && ndist > epsilon))
 		{
+			oncount++;
 			frac = pdist / (pdist - ndist);
 			if (frontcount < outfrontmaxpoints)
 			{
-				*outfrontpoints++ = p[0] + frac * (n[0] - p[0]);
-				*outfrontpoints++ = p[1] + frac * (n[1] - p[1]);
-				*outfrontpoints++ = p[2] + frac * (n[2] - p[2]);
+				*outfrontpoints++ = (float)(p[0] + frac * (n[0] - p[0]));
+				*outfrontpoints++ = (float)(p[1] + frac * (n[1] - p[1]));
+				*outfrontpoints++ = (float)(p[2] + frac * (n[2] - p[2]));
 			}
 			frontcount++;
 			if (backcount < outbackmaxpoints)
 			{
-				*outbackpoints++ = p[0] + frac * (n[0] - p[0]);
-				*outbackpoints++ = p[1] + frac * (n[1] - p[1]);
-				*outbackpoints++ = p[2] + frac * (n[2] - p[2]);
+				*outbackpoints++ = (float)(p[0] + frac * (n[0] - p[0]));
+				*outbackpoints++ = (float)(p[1] + frac * (n[1] - p[1]));
+				*outbackpoints++ = (float)(p[2] + frac * (n[2] - p[2]));
 			}
 			backcount++;
 		}
-		p = n;
-		n += 3;
-		pdist = ndist;
 	}
 	if (neededfrontpoints)
 		*neededfrontpoints = frontcount;
 	if (neededbackpoints)
 		*neededbackpoints = backcount;
+	if (oncountpointer)
+		*oncountpointer = oncount;
 }
 
-void PolygonD_Divide(unsigned int innumpoints, const double *inpoints, double planenormalx, double planenormaly, double planenormalz, double planedist, double epsilon, unsigned int outfrontmaxpoints, double *outfrontpoints, unsigned int *neededfrontpoints, unsigned int outbackmaxpoints, double *outbackpoints, unsigned int *neededbackpoints)
+void PolygonD_Divide(int innumpoints, const double *inpoints, double planenormalx, double planenormaly, double planenormalz, double planedist, double epsilon, int outfrontmaxpoints, double *outfrontpoints, int *neededfrontpoints, int outbackmaxpoints, double *outbackpoints, int *neededbackpoints, int *oncountpointer)
 {
-	unsigned int i, frontcount, backcount;
+	int i, frontcount = 0, backcount = 0, oncount = 0;
 	const double *n, *p;
 	double frac, pdist, ndist;
-	frontcount = 0;
-	backcount = 0;
-	p = inpoints + (innumpoints - 1) * 3;
-	n = inpoints;
-	pdist = p[0] * planenormalx + p[1] * planenormaly + p[2] * planenormalz - planedist;
 	for (i = 0;i < innumpoints;i++)
 	{
+		p = inpoints + i * 3;
+		n = inpoints + ((i + 1) < innumpoints ? (i + 1) : 0) * 3;
+		pdist = p[0] * planenormalx + p[1] * planenormaly + p[2] * planenormalz - planedist;
 		ndist = n[0] * planenormalx + n[1] * planenormaly + n[2] * planenormalz - planedist;
 		if (pdist >= -epsilon)
 		{
+			if (pdist <= epsilon)
+				oncount++;
 			if (frontcount < outfrontmaxpoints)
 			{
 				*outfrontpoints++ = p[0];
@@ -192,6 +192,7 @@ void PolygonD_Divide(unsigned int innumpoints, const double *inpoints, double pl
 		}
 		if ((pdist > epsilon && ndist < -epsilon) || (pdist < -epsilon && ndist > epsilon))
 		{
+			oncount++;
 			frac = pdist / (pdist - ndist);
 			if (frontcount < outfrontmaxpoints)
 			{
@@ -208,13 +209,12 @@ void PolygonD_Divide(unsigned int innumpoints, const double *inpoints, double pl
 			}
 			backcount++;
 		}
-		p = n;
-		n += 3;
-		pdist = ndist;
 	}
 	if (neededfrontpoints)
 		*neededfrontpoints = frontcount;
 	if (neededbackpoints)
 		*neededbackpoints = backcount;
+	if (oncountpointer)
+		*oncountpointer = oncount;
 }