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-rw-r--r--sample/opengl/math_code.cpp488
1 files changed, 488 insertions, 0 deletions
diff --git a/sample/opengl/math_code.cpp b/sample/opengl/math_code.cpp
new file mode 100644
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--- /dev/null
+++ b/sample/opengl/math_code.cpp
@@ -0,0 +1,488 @@
+/*
+ * math_code.cpp
+ *
+ * Created on: 21.03.2011
+ * Author: ttcheblokov
+ */
+
+#include "math_code.h"
+
+void cutLowerHalfspace(float result[4][4], float level, float position, float viewmatrix[4][4], float projectionmatrix[4][4])
+{
+ float viewprojectionmatrix[4][4],tm[4][4],n[4][4]={1.0f,0.0f,0.0f,0.0f,0.0f,1.0f,0.0f,0.0f,0.0f,0.0f,1.0f,0.0f,0.0f,0.0f,0.0f,1.0f};
+ float cplane[4],clip_plane[4];
+
+ cplane[0]=0.0f;
+ cplane[1]=0.1f;
+ cplane[2]=0.0f;
+ cplane[3]=-level*0.1f;//+0.1f;
+
+ mat4Mat4Mul(viewprojectionmatrix, projectionmatrix, viewmatrix);
+ mat4Inverse(tm,viewprojectionmatrix);
+ mat4Vec4Mul(clip_plane,tm,cplane);
+
+ //clip_plane[0]/=cplane[1];
+ //clip_plane[1]/=cplane[1];
+ //clip_plane[2]/=cplane[1];
+ //clip_plane[3]/=cplane[1];
+
+ clip_plane[3] -= 1.0f;
+
+ if((level<position))
+ {
+ clip_plane[0] *= -1.0f;
+ clip_plane[1] *= -1.0f;
+ clip_plane[2] *= -1.0f;
+ clip_plane[3] *= -1.0f;
+ }
+
+ n[0][2]=clip_plane[0];
+ n[1][2]=clip_plane[1];
+ n[2][2]=clip_plane[2];
+ n[3][2]=clip_plane[3];
+
+ mat4Mat4Mul(result,n,projectionmatrix);
+}
+
+void cutUpperHalfspace(float result[4][4], float level, float position, float viewmatrix[4][4], float projectionmatrix[4][4])
+{
+ float viewprojectionmatrix[4][4],tm[4][4],n[4][4]={1.0f,0.0f,0.0f,0.0f,0.0f,1.0f,0.0f,0.0f,0.0f,0.0f,1.0f,0.0f,0.0f,0.0f,0.0f,1.0f};
+ float cplane[4],clip_plane[4];
+
+ cplane[0]=0.0f;
+ cplane[1]=-0.1f;
+ cplane[2]=0.0f;
+ cplane[3]=level*0.1f;//-0.1f;
+
+ mat4Mat4Mul(viewprojectionmatrix, projectionmatrix, viewmatrix);
+ mat4Inverse(tm,viewprojectionmatrix);
+ mat4Vec4Mul(clip_plane,tm,cplane);
+
+ //clip_plane[0]/=cplane[1];
+ //clip_plane[1]/=cplane[1];
+ //clip_plane[2]/=cplane[1];
+ //clip_plane[3]/=cplane[1];
+
+ clip_plane[3] -= 1.0f;
+
+ if((level>position))
+ {
+ clip_plane[0] *= -1.0f;
+ clip_plane[1] *= -1.0f;
+ clip_plane[2] *= -1.0f;
+ clip_plane[3] *= -1.0f;
+ }
+
+ n[0][2]=clip_plane[0];
+ n[1][2]=clip_plane[1];
+ n[2][2]=clip_plane[2];
+ n[3][2]=clip_plane[3];
+
+ mat4Mat4Mul(result,n,projectionmatrix);
+}
+
+void vec3CrossProductNormalized(float result[3], float a[3], float b[3])
+ {
+ float length;
+ result[0]=a[1]*b[2]-a[2]*b[1];
+ result[1]=a[2]*b[0]-a[0]*b[2];
+ result[2]=a[0]*b[1]-a[1]*b[0];
+ length=sqrt(result[0]*result[0]+result[1]*result[1]+result[2]*result[2]);
+ result[0]/=length;
+ result[1]/=length;
+ result[2]/=length;
+ }
+
+ void vec4Sub(float a[4], float b[4], float c[4])
+ {
+ a[0]=b[0]-c[0];
+ a[1]=b[1]-c[1];
+ a[2]=b[2]-c[2];
+ a[3]=b[3]-c[3];
+ }
+ void vec4Add(float a[4], float b[4], float c[4])
+ {
+ a[0]=b[0]+c[0];
+ a[1]=b[1]+c[1];
+ a[2]=b[2]+c[2];
+ a[3]=b[3]+c[3];
+ }
+ float vec4DotProduct(float a[4], float b[4])
+ {
+ return (a[0]*b[0]+a[1]*b[1]+a[2]*b[2]+a[3]*b[3]);
+ }
+
+ float vec3DotProduct(float a[3], float b[3])
+ {
+ return (a[0]*b[0]+a[1]*b[1]+a[2]*b[2]);
+ }
+
+ void vec4Normalize(float a[4])
+ {
+ float length;
+ length=sqrt(a[0]*a[0]+a[1]*a[1]+a[2]*a[2]+a[3]*a[3]);
+ a[0]/=length;
+ a[1]/=length;
+ a[2]/=length;
+ a[3]/=length;
+ }
+ void vec3Normalize(float a[4])
+ {
+ float length;
+ length=sqrt(a[0]*a[0]+a[1]*a[1]+a[2]*a[2]);
+ a[0]/=length;
+ a[1]/=length;
+ a[2]/=length;
+ }
+ void mat4Add(float result[4][4], float a[4][4], float b[4][4])
+ {
+ int i,j;
+ for (i=0;i<4;++i)
+ for (j=0;j<4;++j)
+ result[i][j]=a[i][j]+b[i][j];
+ }
+ void mat4ConstMul(float result[4][4], float a[4][4], float b)
+ {
+ int i,j;
+ for (i=0;i<4;++i)
+ for (j=0;j<4;++j)
+ result[i][j]=a[i][j]*b;
+ }
+ void mat4Transpose(float result[4][4], float a[4][4])
+ {
+ int i,j;
+ for (i=0;i<4;++i)
+ for (j=0;j<4;++j)
+ result[i][j]=a[j][i];
+ }
+ void mat4Mat4Mul(float result[4][4], float a[4][4], float b[4][4])
+ {
+ int i,j,k;
+ float temp;
+
+ for (i=0;i<4;++i)
+ for (j=0;j<4;++j)
+ {
+ temp=0;
+ for(k=0;k<4;++k)
+ {
+ temp+=a[k][j]*b[i][k];
+ }
+ result[i][j]=temp;
+ }
+ }
+ void vec4Mat4Mul(float result[4], float a[4], float b[4][4])
+ {
+ int i,k;
+ float temp;
+
+ for (i=0;i<4;++i)
+ {
+ temp=0;
+ for(k=0;k<4;++k)
+ {
+ temp+=a[k]*b[k][i];
+ }
+ result[i]=temp;
+ }
+ }
+ void mat4Vec4Mul(float result[4], float a[4][4], float b[4])
+ {
+ int i,k;
+ float temp;
+ for (i=0;i<4;++i)
+ {
+ temp=0;
+ for(k=0;k<4;++k)
+ {
+ temp+=a[i][k]*b[k];
+ }
+ result[i]=temp;
+ }
+ }
+ void mat4CreateIdentity (float result[4][4])
+ {
+ int i;
+ for (i=0;i<4;i++)
+ {
+ result[i][0] = 0;
+ result[i][1] = 0;
+ result[i][2] = 0;
+ result[i][3] = 0;
+ }
+ result [0][0] = 1;
+ result [1][1] = 1;
+ result [2][2] = 1;
+ result [3][3] = 1;
+ }
+ void mat4CreateScale (float result[4][4], float x, float y, float z)
+ {
+ int i;
+ for (i=0;i<4;i++)
+ {
+ result[i][0] = 0;
+ result[i][1] = 0;
+ result[i][2] = 0;
+ result[i][3] = 0;
+ }
+ result [0][0] = x;
+ result [1][1] = y;
+ result [2][2] = z;
+ result [3][3] = 1;
+ }
+
+ void mat4CreateTranslation (float result[4][4], float x, float y, float z)
+ {
+ int i;
+ for (i=0;i<4;i++)
+ {
+ result[i][0] = 0;
+ result[i][1] = 0;
+ result[i][2] = 0;
+ result[i][3] = 0;
+ }
+ result [3][0] = x;
+ result [3][1] = y;
+ result [3][2] = z;
+ result [0][0] = 1;
+ result [1][1] = 1;
+ result [2][2] = 1;
+ result [3][3] = 1;
+
+ }
+
+ void mat4CreateProjection (float result[4][4], float w, float h, float zn, float zf)
+ {
+ for (int i=0;i<4;i++)
+ {
+ result[i][0] = 0;
+ result[i][1] = 0;
+ result[i][2] = 0;
+ result[i][3] = 0;
+ }
+ result [0][0] = zn/w;
+ result [1][1] = zn/h;
+ result [2][2] = -(zf+zn)/(zf-zn);
+ result [3][2] = -2.0f*zf*zn/(zf-zn);
+ result [2][3] = -1.0f;
+ }
+
+ void mat4CreateView (float result[4][4], float eyepoint[3], float lookatpoint[3])
+ {
+ float xaxis[3];
+ float yaxis[3];
+ float zaxis[3];
+ float up[3] = {0.0f,0.0f, 1.0f};
+
+ zaxis[0] = - lookatpoint[0] + eyepoint[0];
+ zaxis[1] = - lookatpoint[1] + eyepoint[1];
+ zaxis[2] = - lookatpoint[2] + eyepoint[2];
+
+ vec3Normalize(zaxis);
+ vec3CrossProductNormalized(xaxis, up, zaxis);
+ vec3CrossProductNormalized(yaxis, zaxis, xaxis);
+
+ result[0][0] = xaxis[0];
+ result[0][1] = yaxis[0];
+ result[0][2] = zaxis[0];
+ result[0][3] = 0;
+ result[1][0] = xaxis[1];
+ result[1][1] = yaxis[1];
+ result[1][2] = zaxis[1];
+ result[1][3] = 0;
+ result[2][0] = xaxis[2];
+ result[2][1] = yaxis[2];
+ result[2][2] = zaxis[2];
+ result[2][3] = 0;
+ result[3][0] = -vec3DotProduct(xaxis,eyepoint);
+ result[3][1] = -vec3DotProduct(yaxis,eyepoint);
+ result[3][2] = -vec3DotProduct(zaxis,eyepoint);
+ result[3][3] = 1.0f;
+ }
+
+ void mat4CreateOrthoProjection (float result[4][4], float xmin, float xmax, float ymin, float ymax, float zmin, float zmax)
+ {
+ for(int i=0;i<4;i++)
+ {
+ result[i][0]=0;
+ result[i][1]=0;
+ result[i][2]=0;
+ result[i][3]=0;
+ }
+ result[0][0] = 2.0f/(xmax-xmin);
+ result[1][1] = 2.0f/(ymax-ymin);
+ result[2][2] = -2.0f/(zmax-zmin);
+ result[3][3] = 1.0f;
+ result[3][0] = - (xmax + xmin) / (xmax - xmin);
+ result[3][1] = - (ymax + ymin) / (ymax - ymin);
+ result[3][2] = - (zmax + zmin) / (zmax - zmin);
+
+ }
+
+ void mat4CreateRotation (float result[4][4], float angle, char axis)
+ {
+ int i;
+ for (i=0;i<4;i++)
+ {
+ result[i][0] = 0;
+ result[i][1] = 0;
+ result[i][2] = 0;
+ result[i][3] = 0;
+ }
+ result [3][3] = 1;
+
+ switch (axis)
+ {
+ case 'x':
+ result[0][0]=1.0f;
+ result[0][1]=0.0f;
+ result[0][2]=0.0f;
+ result[1][0]=0.0f;
+ result[1][1]=cos(angle);
+ result[1][2]=sin(angle);
+ result[2][0]=0.0f;
+ result[2][1]=-sin(angle);
+ result[2][2]=cos(angle);
+ break;
+ case 'y':
+ result[0][0]=cos(angle);
+ result[0][1]=0.0f;
+ result[0][2]=-sin(angle);
+ result[1][0]=0.0f;
+ result[1][1]=1.0f;
+ result[1][2]=0.0f;
+ result[2][0]=sin(angle);
+ result[2][1]=0.0f;
+ result[2][2]=cos(angle);
+ break;
+ case 'z':
+ result[0][0]=cos(angle);
+ result[0][1]=sin(angle);
+ result[0][2]=0.0f;
+ result[1][0]=-sin(angle);
+ result[1][1]=cos(angle);
+ result[1][2]=0.0f;
+ result[2][0]=0.0f;
+ result[2][1]=0.0f;
+ result[2][2]=1.0f;
+ break;
+ }
+
+ }
+ float sgn (float a)
+ {
+ if(a>0.0f) return (1.0f);
+ if(a<0.0f) return (-1.0f);
+ return(0.0f);
+ }
+
+ float det2x2(float a,float b,
+ float c,float d)
+ {
+ return a * d - b * c;
+ }
+
+ float det3x3(float a1,float a2,float a3,
+ float b1,float b2,float b3,
+ float c1,float c2,float c3)
+ {
+ float ans;
+ ans = a1 * det2x2( b2, b3, c2, c3)
+ - b1 * det2x2( a2, a3, c2, c3)
+ + c1 * det2x2( a2, a3, b2, b3);
+ return ans;
+ }
+
+ float det4x4(float m[4][4])
+ {
+ float a1,a2,a3,a4,b1,b2,b3,b4,c1,c2,c3,c4,d1,d2,d3,d4;
+
+
+ a1 = m[0][0]; b1 = m[0][1];
+ c1 = m[0][2]; d1 = m[0][3];
+
+ a2 = m[1][0]; b2 = m[1][1];
+ c2 = m[1][2]; d2 = m[1][3];
+
+ a3 = m[2][0]; b3 = m[2][1];
+ c3 = m[2][2]; d3 = m[2][3];
+
+ a4 = m[3][0]; b4 = m[3][1];
+ c4 = m[3][2]; d4 = m[3][3];
+
+ return a1 * det3x3( b2, b3, b4, c2, c3, c4, d2, d3, d4)
+ - b1 * det3x3( a2, a3, a4, c2, c3, c4, d2, d3, d4)
+ + c1 * det3x3( a2, a3, a4, b2, b3, b4, d2, d3, d4)
+ - d1 * det3x3( a2, a3, a4, b2, b3, b4, c2, c3, c4);
+ }
+
+ void adjoint(float adj[4][4],float m[4][4])
+ {
+ float a1,a2,a3,a4,b1,b2,b3,b4,c1,c2,c3,c4,d1,d2,d3,d4;
+
+ a1 = m[0][0]; b1 = m[0][1];
+ c1 = m[0][2]; d1 = m[0][3];
+
+ a2 = m[1][0]; b2 = m[1][1];
+ c2 = m[1][2]; d2 = m[1][3];
+
+ a3 = m[2][0]; b3 = m[2][1];
+ c3 = m[2][2]; d3 = m[2][3];
+
+ a4 = m[3][0]; b4 = m[3][1];
+ c4 = m[3][2]; d4 = m[3][3];
+
+ adj[0][0] = det3x3( b2, b3, b4, c2, c3, c4, d2, d3, d4);
+ adj[1][0] = - det3x3( a2, a3, a4, c2, c3, c4, d2, d3, d4);
+ adj[2][0] = det3x3( a2, a3, a4, b2, b3, b4, d2, d3, d4);
+ adj[3][0] = - det3x3( a2, a3, a4, b2, b3, b4, c2, c3, c4);
+
+ adj[0][1] = - det3x3( b1, b3, b4, c1, c3, c4, d1, d3, d4);
+ adj[1][1] = det3x3( a1, a3, a4, c1, c3, c4, d1, d3, d4);
+ adj[2][1] = - det3x3( a1, a3, a4, b1, b3, b4, d1, d3, d4);
+ adj[3][1] = det3x3( a1, a3, a4, b1, b3, b4, c1, c3, c4);
+
+ adj[0][2] = det3x3( b1, b2, b4, c1, c2, c4, d1, d2, d4);
+ adj[1][2] = - det3x3( a1, a2, a4, c1, c2, c4, d1, d2, d4);
+ adj[2][2] = det3x3( a1, a2, a4, b1, b2, b4, d1, d2, d4);
+ adj[3][2] = - det3x3( a1, a2, a4, b1, b2, b4, c1, c2, c4);
+
+ adj[0][3] = - det3x3( b1, b2, b3, c1, c2, c3, d1, d2, d3);
+ adj[1][3] = det3x3( a1, a2, a3, c1, c2, c3, d1, d2, d3);
+ adj[2][3] = - det3x3( a1, a2, a3, b1, b2, b3, d1, d2, d3);
+ adj[3][3] = det3x3( a1, a2, a3, b1, b2, b3, c1, c2, c3);
+ }
+
+ void mat4Inverse(float result[4][4],float source[4][4])
+ {
+ float adj[4][4];
+ float det;
+ int i,j;
+
+ adjoint(adj,source);
+
+ det = det4x4(source);
+ if (fabs(det) < 1e-8f)
+ {
+ return ;
+ }
+ else
+ {
+ det = 1 / det;
+ for (i = 0; i < 4; i++)
+ for (j = 0; j < 4; j++)
+ result[i][j] = adj[i][j] * det;
+ }
+ }
+
+ void mat4Mat4Copy (float result[4][4], float source[4][4])
+ {
+ int i;
+ for (i=0;i<4;i++)
+ {
+ result[i][0] = source[i][0];
+ result[i][1] = source[i][1];
+ result[i][2] = source[i][2];
+ result[i][3] = source[i][3];
+ }
+ }
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