X-Git-Url: http://git.xonotic.org/?p=xonotic%2Fdarkplaces.git;a=blobdiff_plain;f=polygon.c;h=9a0f1de6d103817924403c9772cbd7ac6c62b049;hp=997cb23a8313c4b5fb7c34e4552daeddbdce77bb;hb=f50a1192fbe86bfdd69d3372620db0b661db5f20;hpb=862c4f3c80e0c8fe22a95e020ec3e8fbb68b754e

diff --git a/polygon.c b/polygon.c
index 997cb23a..9a0f1de6 100644
--- a/polygon.c
+++ b/polygon.c
@@ -1,6 +1,6 @@
 
 /*
-Polygon clipping routines written by Forest Hale and placed into public domain.
+Polygon clipping routines written by Ashley Rose Hale (LadyHavoc) and placed into public domain.
 */
 
 #include <math.h>
@@ -96,21 +96,23 @@ void PolygonD_QuadForPlane(double *outpoints, double planenormalx, double planen
 	outpoints[11] = planedist * planenormalz - quadsize * quadright[2] - quadsize * quadup[2];
 }
 
-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)
+int PolygonF_Clip(int innumpoints, const float *inpoints, float planenormalx, float planenormaly, float planenormalz, float planedist, float epsilon, int outfrontmaxpoints, float *outfrontpoints)
 {
-	int i, frontcount = 0, backcount = 0, oncount = 0;
+	int i, frontcount = 0;
 	const float *n, *p;
-	double frac, pdist, ndist;
-	for (i = 0;i < innumpoints;i++)
+	float frac, pdist, ndist;
+	if (innumpoints < 1)
+		return 0;
+	n = inpoints;
+	ndist = n[0] * planenormalx + n[1] * planenormaly + n[2] * planenormalz - planedist;
+	for(i = 0;i < innumpoints;i++)
 	{
-		p = inpoints + i * 3;
+		p = n;
+		pdist = ndist;
 		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];
@@ -119,19 +121,8 @@ void PolygonF_Divide(int innumpoints, const float *inpoints, float planenormalx,
 			}
 			frontcount++;
 		}
-		if (pdist <= epsilon)
-		{
-			if (backcount < outbackmaxpoints)
-			{
-				*outbackpoints++ = p[0];
-				*outbackpoints++ = p[1];
-				*outbackpoints++ = p[2];
-			}
-			backcount++;
-		}
 		if ((pdist > epsilon && ndist < -epsilon) || (pdist < -epsilon && ndist > epsilon))
 		{
-			oncount++;
 			frac = pdist / (pdist - ndist);
 			if (frontcount < outfrontmaxpoints)
 			{
@@ -140,38 +131,28 @@ void PolygonF_Divide(int innumpoints, const float *inpoints, float planenormalx,
 				*outfrontpoints++ = 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]);
-			}
-			backcount++;
 		}
 	}
-	if (neededfrontpoints)
-		*neededfrontpoints = frontcount;
-	if (neededbackpoints)
-		*neededbackpoints = backcount;
-	if (oncountpointer)
-		*oncountpointer = oncount;
+	return frontcount;
 }
 
-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)
+int PolygonD_Clip(int innumpoints, const double *inpoints, double planenormalx, double planenormaly, double planenormalz, double planedist, double epsilon, int outfrontmaxpoints, double *outfrontpoints)
 {
-	int i, frontcount = 0, backcount = 0, oncount = 0;
+	int i, frontcount = 0;
 	const double *n, *p;
 	double frac, pdist, ndist;
-	for (i = 0;i < innumpoints;i++)
+	if (innumpoints < 1)
+		return 0;
+	n = inpoints;
+	ndist = n[0] * planenormalx + n[1] * planenormaly + n[2] * planenormalz - planedist;
+	for(i = 0;i < innumpoints;i++)
 	{
-		p = inpoints + i * 3;
+		p = n;
+		pdist = ndist;
 		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];
@@ -180,19 +161,8 @@ void PolygonD_Divide(int innumpoints, const double *inpoints, double planenormal
 			}
 			frontcount++;
 		}
-		if (pdist <= epsilon)
-		{
-			if (backcount < outbackmaxpoints)
-			{
-				*outbackpoints++ = p[0];
-				*outbackpoints++ = p[1];
-				*outbackpoints++ = p[2];
-			}
-			backcount++;
-		}
 		if ((pdist > epsilon && ndist < -epsilon) || (pdist < -epsilon && ndist > epsilon))
 		{
-			oncount++;
 			frac = pdist / (pdist - ndist);
 			if (frontcount < outfrontmaxpoints)
 			{
@@ -201,13 +171,133 @@ void PolygonD_Divide(int innumpoints, const double *inpoints, double planenormal
 				*outfrontpoints++ = p[2] + frac * (n[2] - p[2]);
 			}
 			frontcount++;
-			if (backcount < outbackmaxpoints)
+		}
+	}
+	return frontcount;
+}
+
+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)
+{
+	int i, frontcount = 0, backcount = 0, oncount = 0;
+	const float *n, *p;
+	float frac, pdist, ndist;
+	if (innumpoints)
+	{
+		n = inpoints;
+		ndist = n[0] * planenormalx + n[1] * planenormaly + n[2] * planenormalz - planedist;
+		for(i = 0;i < innumpoints;i++)
+		{
+			p = n;
+			pdist = ndist;
+			n = inpoints + ((i + 1) < innumpoints ? (i + 1) : 0) * 3;
+			ndist = n[0] * planenormalx + n[1] * planenormaly + n[2] * planenormalz - planedist;
+			if (pdist >= -epsilon)
+			{
+				if (pdist <= epsilon)
+					oncount++;
+				if (frontcount < outfrontmaxpoints)
+				{
+					*outfrontpoints++ = p[0];
+					*outfrontpoints++ = p[1];
+					*outfrontpoints++ = p[2];
+				}
+				frontcount++;
+			}
+			if (pdist <= epsilon)
 			{
-				*outbackpoints++ = p[0] + frac * (n[0] - p[0]);
-				*outbackpoints++ = p[1] + frac * (n[1] - p[1]);
-				*outbackpoints++ = p[2] + frac * (n[2] - p[2]);
+				if (backcount < outbackmaxpoints)
+				{
+					*outbackpoints++ = p[0];
+					*outbackpoints++ = p[1];
+					*outbackpoints++ = p[2];
+				}
+				backcount++;
+			}
+			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]);
+				}
+				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]);
+				}
+				backcount++;
+			}
+		}
+	}
+	if (neededfrontpoints)
+		*neededfrontpoints = frontcount;
+	if (neededbackpoints)
+		*neededbackpoints = backcount;
+	if (oncountpointer)
+		*oncountpointer = oncount;
+}
+
+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)
+{
+	int i = 0, frontcount = 0, backcount = 0, oncount = 0;
+	const double *n, *p;
+	double frac, pdist, ndist;
+	if (innumpoints)
+	{
+		n = inpoints;
+		ndist = n[0] * planenormalx + n[1] * planenormaly + n[2] * planenormalz - planedist;
+		for(i = 0;i < innumpoints;i++)
+		{
+			p = n;
+			pdist = ndist;
+			n = inpoints + ((i + 1) < innumpoints ? (i + 1) : 0) * 3;
+			ndist = n[0] * planenormalx + n[1] * planenormaly + n[2] * planenormalz - planedist;
+			if (pdist >= -epsilon)
+			{
+				if (pdist <= epsilon)
+					oncount++;
+				if (frontcount < outfrontmaxpoints)
+				{
+					*outfrontpoints++ = p[0];
+					*outfrontpoints++ = p[1];
+					*outfrontpoints++ = p[2];
+				}
+				frontcount++;
+			}
+			if (pdist <= epsilon)
+			{
+				if (backcount < outbackmaxpoints)
+				{
+					*outbackpoints++ = p[0];
+					*outbackpoints++ = p[1];
+					*outbackpoints++ = p[2];
+				}
+				backcount++;
+			}
+			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]);
+				}
+				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]);
+				}
+				backcount++;
 			}
-			backcount++;
 		}
 	}
 	if (neededfrontpoints)