X-Git-Url: http://git.mutantstargoat.com?a=blobdiff_plain;f=src%2Fhair.cc;h=2431f509cf7669331698b5327741f2035d4f6007;hb=2c4aeaa83ca06d604c084f1fe146ee7f51e30f90;hp=e4843fb0c9168a058946e31cb6e1e45c6e68d5ef;hpb=da5cbacf755273da510c37c819a59c7fe9894c4e;p=hair

diff --git a/src/hair.cc b/src/hair.cc
index e4843fb..2431f50 100644
--- a/src/hair.cc
+++ b/src/hair.cc
@@ -1,3 +1,6 @@
+#include <GL/glew.h>
+
+#include <float.h>
 #include <gmath/gmath.h>
 #include <stdlib.h>
 #include <string>
@@ -10,8 +13,14 @@ struct Triangle {
 	Vec3 n[3];
 };
 
-Hair::Hair() {}
-Hair::~Hair() {}
+Hair::Hair()
+{
+	hair_length = 0.5;
+}
+
+Hair::~Hair()
+{
+}
 
 static Vec3 calc_rand_point(const Triangle &tr, Vec3 *bary)
 {
@@ -25,7 +34,7 @@ static Vec3 calc_rand_point(const Triangle &tr, Vec3 *bary)
 
 	float c = 1 - (u + v);
 
-	Vec3 rp = u * tr.v[0] + v * tr.v[1] + c * tr.v[3];
+	Vec3 rp = u * tr.v[0] + v * tr.v[1] + c * tr.v[2];
 
 	bary->x = u;
 	bary->y = v;
@@ -36,11 +45,18 @@ static Vec3 calc_rand_point(const Triangle &tr, Vec3 *bary)
 
 static void get_spawn_triangles(const Mesh *m, float thresh, std::vector<Triangle> *faces)
 {
+	if (!m) {
+		fprintf(stderr, "Func: %s, invalid mesh.\n", __func__);
+		exit(1);
+	}
+	float min_y = FLT_MAX;
+	float max_y = -FLT_MAX;
+
 	for(size_t i=0; i<m->indices.size() / 3; i++) {
 		bool is_spawn = true;
 		int idx[3];
 		for(int j=0; j<3; j++) {
-			idx[j] = i * 3 + j;
+			idx[j] = m->indices[i * 3 + j];
 			float c = (m->colors[idx[j]].x + m->colors[idx[j]].y + m->colors[idx[j]].z) / 3;
 			if (c >= thresh) {
 				is_spawn = false;
@@ -53,10 +69,15 @@ static void get_spawn_triangles(const Mesh *m, float thresh, std::vector<Triangl
 			for(int j=0; j<3; j++) {
 				t.v[j] = m->vertices[idx[j]];
 				t.n[j] = m->normals[idx[j]];
+				if(t.v[j].y < min_y)
+					min_y = t.v[j].y;
+				if(t.v[j].y > max_y)
+					max_y = t.v[j].y;
 			}
 			faces->push_back(t);
 		}
 	}
+/*	printf("spawn tri AABB: min y: %f max y: %f\n", min_y, max_y);*/
 }
 
 bool Hair::init(const Mesh *m, int max_num_spawns, float thresh)
@@ -65,6 +86,11 @@ bool Hair::init(const Mesh *m, int max_num_spawns, float thresh)
 	kdtree *kd = kd_create(3);
 	const float min_dist = 0.05;
 
+	if(!m) {
+		fprintf(stderr, "Func %s: invalid mesh.\n", __func__);
+		return false;
+	}
+
 	get_spawn_triangles(m, thresh, &faces);
 
 	for(int i = 0; i < max_num_spawns; i++) {
@@ -75,24 +101,82 @@ bool Hair::init(const Mesh *m, int max_num_spawns, float thresh)
 		Vec3 rpoint = calc_rand_point(rtriangle, &bary);
 
 		kdres *res = kd_nearest3f(kd, rpoint.x, rpoint.y, rpoint.z);
-		if (!kd_res_end(res)) {
+
+		if (res && !kd_res_end(res)) {
 			Vec3 nearest;
 			kd_res_item3f(res, &nearest.x, &nearest.y, &nearest.z);
 			if(distance_sq(rpoint, nearest) < min_dist * min_dist)
 				continue;
 		}
 
+		HairStrand strand;
 		/* weighted sum of the triangle's vertex normals */
-		Vec3 spawn_dir = rtriangle.n[0] * bary.x + rtriangle.n[1] * bary.y + rtriangle.n[2] * bary.z;
-		spawn_directions.push_back(normalize(spawn_dir));
-		spawn_points.push_back(rpoint);
+		strand.spawn_dir = normalize(rtriangle.n[0] * bary.x + rtriangle.n[1] * bary.y + rtriangle.n[2] * bary.z);
+		strand.spawn_pt = rpoint;
+		hair.push_back(strand);
+
 		kd_insert3f(kd, rpoint.x, rpoint.y, rpoint.z, 0);
 	}
 
 	kd_free(kd);
+
+	for(size_t i=0; i<hair.size(); i++) {
+		hair[i].pos = hair[i].spawn_pt + hair[i].spawn_dir * hair_length;
+		
+		/* orthonormal basis */
+		Vec3 vk = hair[i].spawn_dir;
+		Vec3 vi = Vec3(1, 0, 0);
+		if(fabs(vk.x > 0.99)) {
+			vi = Vec3(0, -1, 0);
+		}
+		Vec3 vj = normalize(cross(vk, vi));
+		vi = cross(vj, vk);
+
+		/* identity when the hair points to the z axis */
+		Mat4 basis = Mat4(vi, vj, vk);
+
+		for(int j=0; j<3; j++) {
+			float angle = (float)j / 3.0 * 2 * M_PI;
+			/* dir of each anchor relative to hair end */
+			Vec3 dir = Vec3(cos(angle), sin(angle), 0);
+			dir = basis * dir;
+			hair[i].anchor_dirs[j] = hair[i].pos + dir - hair[i].spawn_pt;
+		}
+	}
 	return true;
 }
 
 void Hair::draw() const
 {
+	glPushAttrib(GL_ENABLE_BIT);
+//	glDisable(GL_DEPTH_TEST);
+	glDisable(GL_LIGHTING);
+	glPointSize(5);
+	glLineWidth(2);
+
+	glBegin(GL_LINES);
+	for(size_t i=0; i<hair.size(); i++) {
+		glColor3f(1, 0, 1);
+		glVertex3f(hair[i].pos.x, hair[i].pos.y, hair[i].pos.z);
+		Vec3 p = hair[i].spawn_pt;
+		glVertex3f(p.x, p.y, p.z);
+	}
+	glEnd();
+
+	glBegin(GL_POINTS);
+	glColor3f(0.5, 1.0, 0.5);
+	for(size_t i=0; i<hair.size(); i++) {
+		for(int j=0; j<3; j++) {
+			Vec3 p = hair[i].spawn_pt + hair[i].anchor_dirs[j];
+			glVertex3f(p.x, p.y, p.z);
+		}
+	}
+	glEnd();
+
+	glPopAttrib();
+}
+
+void Hair::set_transform(Mat4 &xform)
+{
+	this->xform = xform;
 }