setup examples and clean codebase

include/klein/norm.h

@@ -0,0 +1,118 @@
+static inline
+void __calculate_normal( float *p1, float *p2, float *p3, float *normal, unsigned char n)
+{ unsigned char i;
+	float alpha;
+	float *v1, *v2, *v3;
+	float *u1, *u2, *u3;
+
+	v1 = malloc(n * sizeof(float));
+	v2 = malloc(n * sizeof(float));
+	v3 = malloc(n * sizeof(float));
+	u1 = malloc(n * sizeof(float));
+	u2 = malloc(n * sizeof(float));
+	u3 = malloc(n * sizeof(float));
+
+	/*
+		Calculate a normal vector of a plain using Gram-Schmidt process
+	*/
+	{
+		for (i = 0; i < n; ++i)
+		{
+			v1[i] = p2[i] - p1[i];
+			v2[i] = p3[i] - p1[i];
+			v3[i] = p1[i];
+		}
+
+		for (i = 0; i < n; ++i)
+		{
+			u1[i] = v1[i];
+		}
+
+		{
+			float proj[n];
+			float dot_v2_u1 = 0.0f, dot_u1_u1 = 0.0f;
+			for (i = 0; i < n; ++i)
+			{
+				dot_v2_u1 += v2[i] * u1[i];
+				dot_u1_u1 += u1[i] * u1[i];
+			}
+			alpha = dot_v2_u1 / dot_u1_u1;
+
+			for (i = 0; i < n; ++i)
+			{
+				proj[i] = u1[i] * alpha;
+				u2[i] = v2[i] - proj[i];
+			}
+		}
+
+		{
+			float proj1[n], proj2[n];
+			float dot_v3_u1 = 0.0f, dot_u1_u1 = 0.0f;
+			float dot_v3_u2 = 0.0f, dot_u2_u2 = 0.0f;
+
+			for (i = 0; i < n; ++i)
+			{
+				dot_v3_u1 += v3[i] * u1[i];
+				dot_u1_u1 += u1[i] * u1[i];
+			}
+			for (i = 0; i < n; ++i)
+			{
+				proj1[i] = u1[i] * (dot_v3_u1 / dot_u1_u1);
+			}
+
+			for (i = 0; i < n; ++i)
+			{
+				dot_v3_u2 += v3[i] * u2[i];
+				dot_u2_u2 += u2[i] * u2[i];
+			}
+			for (i = 0; i < n; ++i)
+			{
+				proj2[i] = u2[i] * (dot_v3_u2 / dot_u2_u2);
+				u3[i] = v3[i] - proj1[i] - proj2[i];
+			}
+		}
+
+		float magnitude = 0.0f;
+		for (i = 0; i < n; ++i)
+		{
+			magnitude += u3[i] * u3[i];
+		}
+		magnitude = sqrtf(magnitude);
+
+		for (i = 0; i < n; ++i)
+		{
+			normal[i] = u3[i] / magnitude;
+		}
+
+		free(v1);
+		free(v2);
+		free(v3);
+		free(u1);
+		free(u2);
+		free(u3);
+		return;
+	}
+}
+
+void klein_normalize(struct klein * klein)
+{
+	unsigned long i;
+	unsigned char j;
+	float *norm_vec;
+
+	klein->normals = malloc((klein->dim * klein->vertex_size) * sizeof(float));
+	norm_vec = malloc(klein->dim * sizeof(float));
+
+	for (i = 0; i < klein->vertex_size; i += 3 * klein->dim)
+	{
+		__calculate_normal(klein->vertex + i, klein->vertex + i + klein->dim, klein->vertex + i + 2 * klein->dim, norm_vec, klein->dim);
+		for (j = 0; j < klein->dim; ++j )
+		{
+			(klein->normals + i)[j]=norm_vec[j];
+			(klein->normals + i + klein->dim)[j]=norm_vec[j];
+			(klein->normals + i + 2*klein->dim)[j]=norm_vec[j];
+		}
+	}
+
+	free(norm_vec);
+}