* mcgarvey@eng.utah.edu
*/
-#ifndef __TRI_H__
-#define __TRI_H__
+#ifndef _TRI_H_
+#define _TRI_H_
+#include "aabb.h"
#include "mat.h"
#include "vert.h"
/*
* Initialize a triangle.
*/
-__fast__
+INLINE_MAYBE
void tri_init(tri_t* t, vert_t a, vert_t b, vert_t c)
{
t->a = a;
/*
* Create a new triangle.
*/
-__fast__
+INLINE_MAYBE
tri_t tri_new(vert_t a, vert_t b, vert_t c)
{
tri_t t;
/*
* Create a new triangle on the heap.
*/
-__fast__
+INLINE_MAYBE
tri_t* tri_alloc(vert_t a, vert_t b, vert_t c)
{
tri_t* t = (tri_t*)mem_alloc(sizeof(tri_t));
/*
* Apply a transformation matrix to alter the triangle geometry.
*/
-__fast__
+INLINE_MAYBE
tri_t tri_transform(tri_t t, mat_t m)
{
t.a.v = mat_apply(m, t.a.v);
t.b.v = mat_apply(m, t.b.v);
t.c.v = mat_apply(m, t.c.v);
+ t.a.n.w = t.b.n.w = t.c.n.w = S(0.0);
+ t.a.n = vec_normalize(mat_apply(m, t.a.n));
+ t.b.n = vec_normalize(mat_apply(m, t.b.n));
+ t.c.n = vec_normalize(mat_apply(m, t.c.n));
+ return t;
+}
+
+/*
+ * Perform a homogeneous divide on the geometry.
+ */
+INLINE_MAYBE
+tri_t tri_homodiv(tri_t t)
+{
+ t.a.v = vec_homodiv(t.a.v);
+ t.b.v = vec_homodiv(t.b.v);
+ t.c.v = vec_homodiv(t.c.v);
return t;
}
+/*
+ * Calculate a normal vector.
+ */
+INLINE_MAYBE
+vec_t tri_normal(tri_t t)
+{
+ vec_t n = vec_cross(vec_sub(t.b.v, t.a.v), vec_sub(t.c.v, t.a.v));
+ return n;
+}
+
+
+/*
+ * Calculate the AABB for the triangle.
+ */
+INLINE_MAYBE
+aabb_t tri_aabb(tri_t t)
+{
+ aabb_t b;
+ b.min = vec_new(scal_min2(t.a.v.x, t.b.v.x, t.c.v.x),
+ scal_min2(t.a.v.y, t.b.v.y, t.c.v.y),
+ scal_min2(t.a.v.z, t.b.v.z, t.c.v.z));
+ b.max = vec_new(scal_max2(t.a.v.x, t.b.v.x, t.c.v.x),
+ scal_max2(t.a.v.y, t.b.v.y, t.c.v.y),
+ scal_max2(t.a.v.z, t.b.v.z, t.c.v.z));
+ return b;
+}
+
+
/*
* Get the barycentric coordinates of a vector against a triangle. The
* returned coordinates will be a linear combination, but they may not
* to check if they really are barycentric coordinates, meaning the point
* vector v is inside the triangle, ignoring the Z components.
*/
-vec_t tri_barycentric(const tri_t* t, vec_t v);
+INLINE_MAYBE
+bool tri_barycentric(tri_t t, scal_t* b, vec_t v)
+{
+ scal_t denom = (t.b.v.y - t.c.v.y) * (t.a.v.x - t.c.v.x) + (t.c.v.x - t.b.v.x) * (t.a.v.y - t.c.v.y);
+ b[0] = ((t.b.v.y - t.c.v.y) * (v.x - t.c.v.x) + (t.c.v.x - t.b.v.x) * (v.y - t.c.v.y)) / denom;
+ b[1] = ((t.c.v.y - t.a.v.y) * (v.x - t.c.v.x) + (t.a.v.x - t.c.v.x) * (v.y - t.c.v.y)) / denom;
+ b[2] = S(1.0) - b[0] - b[1];
+ if (S(0.0) <= b[0] && b[0] <= S(1.0) &&
+ S(0.0) <= b[1] && b[1] <= S(1.0) &&
+ S(0.0) <= b[2] && b[2] <= S(1.0)) {
+ return true;
+ }
+ return false;
+}
+
+
+/*
+ * Find the midpoint of the triangle.
+ */
+INLINE_MAYBE
+vec_t tri_midpoint(tri_t t)
+{
+ return vec_new((t.a.v.x + t.b.v.x + t.c.v.x) * S(0.333),
+ (t.a.v.y + t.b.v.y + t.c.v.y) * S(0.333),
+ (t.a.v.z + t.b.v.z + t.c.v.z) * S(0.333));
+}
+
+/*
+ * Get the average color of the triangle.
+ */
+INLINE_MAYBE
+color_t tri_color(tri_t t)
+{
+ scal_t b[] = {S(0.333), S(0.333), S(0.333)};
+ return color_interp2(t.a.c, t.b.c, t.c.c, b);
+}
+
+
+/*
+ * Get an interpolated z-value at the barycentric coordinates.
+ */
+INLINE_MAYBE
+scal_t tri_z(tri_t t, scal_t b[3])
+{
+ return t.a.v.z * b[0] + t.b.v.z * b[1] + t.c.v.z * b[2];
+}
+
+/*
+ * Calculate an interpolated point.
+ */
+INLINE_MAYBE
+vec_t tri_point(tri_t t, scal_t b[3])
+{
+ return vec_interp(t.a.v, t.b.v, t.c.v, b);
+}
+
+/*
+ * Calculate an interpolated normal.
+ */
+INLINE_MAYBE
+vec_t tri_normal2(tri_t t, scal_t b[3])
+{
+ return vec_normalize(vec_interp(t.a.n, t.b.n, t.c.n, b));
+}
+
+/*
+ * Calculate an interpolated texture coordinate.
+ */
+INLINE_MAYBE
+vec_t tri_tcoord(tri_t t, scal_t b[3])
+{
+#if PERSPECTIVE_FIX
+ return vec_tinterp(t.a.t, t.b.t, t.c.t, b);
+#else
+ return vec_interp(t.a.t, t.b.t, t.c.t, b);
+#endif
+}
+
+/*
+ * Calculate an entirely new vertex within the triangle based on barycentric
+ * coordinates.
+ */
+INLINE_MAYBE
+vert_t tri_interp(tri_t t, scal_t b[3])
+{
+ vert_t v = vert_new(tri_point(t, b));
+ v.c = color_interp2(t.a.c, t.b.c, t.c.c, b);
+ v.n = tri_normal2(t, b);
+ v.t = tri_tcoord(t, b);
+ return v;
+}
-#endif // __TRI_H__
+#endif // _TRI_H_