Initial revision

git-svn-id: svn://svn.icculus.org/blackshades/trunk@2 5198baeb-e213-0410-be47-fc2ff85ca46f

1 files changed, 153 insertions, 0 deletions

diff --git a/Source/Frustum.cpp b/Source/Frustum.cpp
new file mode 100644
index 0000000..32639e7
--- /dev/null
+++ b/Source/Frustum.cpp
@@ -0,0 +1,153 @@
+#include "frustum.h"
+#include <math.h>
+#include "gl.h"
+
+void FRUSTUM::
+	GetFrustum() {
+	float projmatrix[16];
+	float mvmatrix[16];
+	float clip[16];
+	float t;
+	
+	glGetFloatv(GL_PROJECTION_MATRIX, projmatrix);
+	glGetFloatv(GL_MODELVIEW_MATRIX, mvmatrix);
+	
+	// Combine the matrices
+	clip[0]	= mvmatrix[0] * projmatrix[0] + mvmatrix[1] * projmatrix[4] + mvmatrix[2] * projmatrix[8] + mvmatrix[3] * projmatrix[12];
+	clip[1] = mvmatrix[0] * projmatrix[1] + mvmatrix[1] * projmatrix[5] + mvmatrix[2] * projmatrix[9] + mvmatrix[3] * projmatrix[13];
+	clip[2] = mvmatrix[0] * projmatrix[2] + mvmatrix[1] * projmatrix[6] + mvmatrix[2] * projmatrix[10] + mvmatrix[3] * projmatrix[14];
+	clip[3] = mvmatrix[0] * projmatrix[3] + mvmatrix[1] * projmatrix[7] + mvmatrix[2] * projmatrix[11] + mvmatrix[3] * projmatrix[15];
+	
+	clip[4] = mvmatrix[4] * projmatrix[0] + mvmatrix[5] * projmatrix[4] + mvmatrix[6] * projmatrix[8] + mvmatrix[7] * projmatrix[12];
+	clip[5] = mvmatrix[4] * projmatrix[1] + mvmatrix[5] * projmatrix[5] + mvmatrix[6] * projmatrix[9] + mvmatrix[7] * projmatrix[13];
+	clip[6] = mvmatrix[4] * projmatrix[2] + mvmatrix[5] * projmatrix[6] + mvmatrix[6] * projmatrix[10] + mvmatrix[7] * projmatrix[14];
+	clip[7] = mvmatrix[4] * projmatrix[3] + mvmatrix[5] * projmatrix[7] + mvmatrix[6] * projmatrix[11] + mvmatrix[7] * projmatrix[15];
+	
+	clip[8] = mvmatrix[8] * projmatrix[0] + mvmatrix[9] * projmatrix[4] + mvmatrix[10] * projmatrix[8] + mvmatrix[11] * projmatrix[12];
+	clip[9] = mvmatrix[8] * projmatrix[1] + mvmatrix[9] * projmatrix[5] + mvmatrix[10] * projmatrix[9] + mvmatrix[11] * projmatrix[13];
+	clip[10] = mvmatrix[8] * projmatrix[2] + mvmatrix[9] * projmatrix[6] + mvmatrix[10] * projmatrix[10] + mvmatrix[11] * projmatrix[14];
+	clip[11] = mvmatrix[8] * projmatrix[3] + mvmatrix[9] * projmatrix[7] + mvmatrix[10] * projmatrix[11] + mvmatrix[11] * projmatrix[15];
+	
+	clip[12] = mvmatrix[12] * projmatrix[0] + mvmatrix[13] * projmatrix[4] + mvmatrix[14] * projmatrix[8] + mvmatrix[15] * projmatrix[12];
+	clip[13] = mvmatrix[12] * projmatrix[1] + mvmatrix[13] * projmatrix[5] + mvmatrix[14] * projmatrix[9] + mvmatrix[15] * projmatrix[13];
+	clip[14] = mvmatrix[12] * projmatrix[2] + mvmatrix[13] * projmatrix[6] + mvmatrix[14] * projmatrix[10] + mvmatrix[15] * projmatrix[14];
+	clip[15] = mvmatrix[12] * projmatrix[3] + mvmatrix[13] * projmatrix[7] + mvmatrix[14] * projmatrix[11] + mvmatrix[15] * projmatrix[15];
+	
+	// Right plane
+	frustum[0][0] = clip[3] - clip[0];
+	frustum[0][1] = clip[7] - clip[4];
+	frustum[0][2] = clip[11] - clip[8];
+	frustum[0][3] = clip[15] - clip[12];
+	
+	// Left plane
+	frustum[1][0] = clip[3] + clip[0];
+	frustum[1][1] = clip[7] + clip[4];
+	frustum[1][2] = clip[11] + clip[8];
+	frustum[1][3] = clip[15] + clip[12];
+	
+	// Bottom plane
+	frustum[2][0] = clip[3] + clip[1];
+	frustum[2][1] = clip[7] + clip[5];
+	frustum[2][2] = clip[11] + clip[9];
+	frustum[2][3] = clip[15] + clip[13];
+	
+	// Top plane
+	frustum[3][0] = clip[3] - clip[1];
+	frustum[3][1] = clip[7] - clip[5];
+	frustum[3][2] = clip[11] - clip[9];
+	frustum[3][3] = clip[15] - clip[13];
+	
+	// Far plane
+	frustum[4][0] = clip[3] - clip[2];
+	frustum[4][1] = clip[7] - clip[6];
+	frustum[4][2] = clip[11] - clip[10];
+	frustum[4][3] = clip[15] - clip[14];
+	
+	// Near plane
+	frustum[5][0] = clip[3] + clip[2];
+	frustum[5][1] = clip[7] + clip[6];
+	frustum[5][2] = clip[11] + clip[10];
+	frustum[5][3] = clip[15] + clip[14];
+}
+
+int FRUSTUM::
+	CubeInFrustum(float x, float y, float z, float size) {
+	int c, c2;
+	
+	for(int i=0; i<6; i++) {
+		c=0;
+		if(frustum[i][0] * (x-size) + frustum[i][1] * (y-size) + frustum[i][2] * (z-size) + frustum[i][3] > 0)
+			c++;
+		if(frustum[i][0] * (x+size) + frustum[i][1] * (y-size) + frustum[i][2] * (z-size) + frustum[i][3] > 0)
+			c++;
+		if(frustum[i][0] * (x-size) + frustum[i][1] * (y+size) + frustum[i][2] * (z-size) + frustum[i][3] > 0)
+			c++;
+		if(frustum[i][0] * (x+size) + frustum[i][1] * (y+size) + frustum[i][2] * (z-size) + frustum[i][3] > 0)
+			c++;
+		if(frustum[i][0] * (x-size) + frustum[i][1] * (y-size) + frustum[i][2] * (z+size) + frustum[i][3] > 0)
+			c++;
+		if(frustum[i][0] * (x+size) + frustum[i][1] * (y-size) + frustum[i][2] * (z+size) + frustum[i][3] > 0)
+			c++;
+		if(frustum[i][0] * (x-size) + frustum[i][1] * (y+size) + frustum[i][2] * (z+size) + frustum[i][3] > 0)
+			c++;
+		if(frustum[i][0] * (x+size) + frustum[i][1] * (y+size) + frustum[i][2] * (z+size) + frustum[i][3] > 0)
+			c++;
+		if(c==0)
+			return 0;
+		if(c==8)
+			c2++;
+	}
+	if(c2>=6)
+		return 2;
+	else
+		return 1;
+}
+
+int FRUSTUM::
+	CubeInFrustum(float x, float y, float z, float size, float height) {
+	int c, c2;
+	
+	for(int i=0; i<6; i++) {
+		c=0;
+		if(frustum[i][0] * (x-size) + frustum[i][1] * (y-height) + frustum[i][2] * (z-size) + frustum[i][3] > 0)
+			c++;
+		if(frustum[i][0] * (x+size) + frustum[i][1] * (y-height) + frustum[i][2] * (z-size) + frustum[i][3] > 0)
+			c++;
+		if(frustum[i][0] * (x-size) + frustum[i][1] * (y+height) + frustum[i][2] * (z-size) + frustum[i][3] > 0)
+			c++;
+		if(frustum[i][0] * (x+size) + frustum[i][1] * (y+height) + frustum[i][2] * (z-size) + frustum[i][3] > 0)
+			c++;
+		if(frustum[i][0] * (x-size) + frustum[i][1] * (y-height) + frustum[i][2] * (z+size) + frustum[i][3] > 0)
+			c++;
+		if(frustum[i][0] * (x+size) + frustum[i][1] * (y-height) + frustum[i][2] * (z+size) + frustum[i][3] > 0)
+			c++;
+		if(frustum[i][0] * (x-size) + frustum[i][1] * (y+height) + frustum[i][2] * (z+size) + frustum[i][3] > 0)
+			c++;
+		if(frustum[i][0] * (x+size) + frustum[i][1] * (y+height) + frustum[i][2] * (z+size) + frustum[i][3] > 0)
+			c++;
+		if(c==0)
+			return 0;
+		if(c==8)
+			c2++;
+	}
+	if(c2>=6)
+		return 2;
+	else
+		return 1;
+}
+
+int FRUSTUM::
+	SphereInFrustum(float x, float y, float z, float radius) {
+	int  c2;
+	
+	for(int i=0; i<6; i++) {
+		if(frustum[i][0] * x + frustum[i][1] * y + frustum[i][2] * z + frustum[i][3] > -1*radius)
+			c2++;
+		else
+			return 0;
+	}
+	if(c2>=6)
+		return 2;
+	else
+		return 1;
+}
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