# HG changeset patch
# User John Tsiombikas <nuclear@member.fsf.org>
# Date 1279949297 -3600
# Node ID a09622aaa0439bf5bdd43116d2eccf87aa12b44f
# Parent  deaf85acf6aff4694ba2b5f4fb5cbf882ab525a0
moving to triangles

diff -r deaf85acf6af -r a09622aaa043 rt.cl
--- a/rt.cl	Fri Jul 23 19:48:43 2010 +0100
+++ b/rt.cl	Sat Jul 24 06:28:17 2010 +0100
@@ -1,14 +1,25 @@
 struct RendInfo {
 	int xsz, ysz;
-	int num_sph, num_lights;
+	int num_faces, num_lights;
 	int max_iter;
 };
 
-struct Sphere {
+struct Vertex {
 	float4 pos;
+	float4 normal;
+	float2 tex;
+};
+
+struct Face {
+	struct Vertex v[3];
+	float4 normal;
+	int matid;
+};
+
+struct Material {
 	float4 kd, ks;
-	float radius;
-	float spow, kr, kt;
+	float kr, kt;
+	float spow;
 };
 
 struct Light {
@@ -22,22 +33,25 @@
 struct SurfPoint {
 	float t;
 	float4 pos, norm;
-	global const struct Sphere *obj;
+	global const struct Face *obj;
+	global const struct Material *mat;
 };
 
 #define EPSILON 1e-6
 
 float4 shade(struct Ray ray, struct SurfPoint sp,
 		global const struct Light *lights, int num_lights);
-bool intersect(struct Ray ray, global const struct Sphere *sph, struct SurfPoint *sp);
+bool intersect(struct Ray ray, global const struct Face *face, struct SurfPoint *sp);
 float4 reflect(float4 v, float4 n);
 float4 transform(float4 v, global const float *xform);
 struct Ray transform_ray(global const struct Ray *ray, global const float *xform);
+float4 calc_bary(float4 pt, global const struct Face *face);
 
 
 kernel void render(global float4 *fb,
 		global const struct RendInfo *rinf,
-		global const struct Sphere *sphlist,
+		global const struct Face *faces,
+		global const struct Material *matlib,
 		global const struct Light *lights,
 		global const struct Ray *primrays,
 		global const float *xform)
@@ -50,13 +64,14 @@
 	sp0.t = FLT_MAX;
 	sp0.obj = 0;
 
-	for(int i=0; i<rinf->num_sph; i++) {
-		if(intersect(ray, sphlist + i, &sp) && sp.t < sp0.t) {
+	for(int i=0; i<rinf->num_faces; i++) {
+		if(intersect(ray, faces + i, &sp) && sp.t < sp0.t) {
 			sp0 = sp;
 		}
 	}
 
 	if(sp0.obj) {
+		sp0.mat = matlib + sp0.obj->matid;
 		fb[idx] = shade(ray, sp0, lights, rinf->num_lights);
 	} else {
 		fb[idx] = (float4)(0, 0, 0, 0);
@@ -75,49 +90,46 @@
 		float4 vref = reflect(vdir, sp.norm);
 
 		float diff = fmax(dot(ldir, sp.norm), 0.0f);
-		float spec = powr(fmax(dot(ldir, vref), 0.0f), sp.obj->spow);
+		float spec = powr(fmax(dot(ldir, vref), 0.0f), sp.mat->spow);
 
-		dcol += sp.obj->kd * diff * lights[i].color;
-		scol += sp.obj->ks * spec * lights[i].color;
+		dcol += sp.mat->kd * diff * lights[i].color;
+		scol += sp.mat->ks * spec * lights[i].color;
 	}
 
 	return dcol + scol;
 }
 
 bool intersect(struct Ray ray,
-		global const struct Sphere *sph,
+		global const struct Face *face,
 		struct SurfPoint *sp)
 {
-	float4 dir = ray.dir;
-	float4 orig = ray.origin;
-	float4 spos = sph->pos;
+	float ndotdir = dot(face->normal, ray.dir);
+	if(fabs(ndotdir) <= EPSILON) {
+		return false;
+	}
 
-	float a = dot(dir, dir);
-	float b = 2.0 * dir.x * (orig.x - spos.x) +
-		2.0 * dir.y * (orig.y - spos.y) +
-		2.0 * dir.z * (orig.z - spos.z);
-	float c = dot(spos, spos) + dot(orig, orig) +
-		2.0 * dot(-spos, orig) - sph->radius * sph->radius;
+	float4 pt = face->v[0].pos;
+	float4 vec = pt - ray.origin;
 
-	float d = b * b - 4.0 * a * c;
-	if(d < 0.0) return false;
-
-	float sqrt_d = sqrt(d);
-	float t1 = (-b + sqrt_d) / (2.0 * a);
-	float t2 = (-b - sqrt_d) / (2.0 * a);
-
-	if(t1 < EPSILON) t1 = t2;
-	if(t2 < EPSILON) t2 = t1;
-	float t = t1 < t2 ? t1 : t2;
+	float ndotvec = dot(face->normal, vec);
+	float t = ndotvec / ndotdir;
 
 	if(t < EPSILON || t > 1.0) {
 		return false;
 	}
+	pt = ray.origin + ray.dir * t;
+
+	float4 bc = calc_bary(pt, face);
+	float bc_sum = bc.x + bc.y + bc.z;
+
+	if(bc_sum < -EPSILON || bc_sum > 1.0) {
+		return false;
+	}
 
 	sp->t = t;
-	sp->pos = orig + dir * sp->t;
-	sp->norm = (sp->pos - spos) / sph->radius;
-	sp->obj = sph;
+	sp->pos = pt;
+	sp->norm = face->normal;
+	sp->obj = face;
 	return true;
 }
 
@@ -151,3 +163,29 @@
 	res.dir = transform(ray->dir, xform);
 	return res;
 }
+
+float4 calc_bary(float4 pt, global const struct Face *face)
+{
+	float4 bc = {0, 0, 0, 0};
+
+	float4 vi = face->v[1].pos - face->v[0].pos;
+	float4 vj = face->v[2].pos - face->v[0].pos;
+	float area = fabs(dot(cross(vi, vj), face->normal) / 2.0);
+	if(area < EPSILON) {
+		return bc;
+	}
+
+	float4 pv0 = face->v[0].pos - pt;
+	float4 pv1 = face->v[1].pos - pt;
+	float4 pv2 = face->v[2].pos - pt;
+
+	// calculate the areas of each sub-triangle
+	float a0 = fabs(dot(cross(pv1, pv2), face->normal) / 2.0);
+	float a1 = fabs(dot(cross(pv2, pv0), face->normal) / 2.0);
+	float a2 = fabs(dot(cross(pv0, pv1), face->normal) / 2.0);
+
+	bc.x = a0 / area;
+	bc.y = a1 / area;
+	bc.z = a2 / area;
+	return bc;
+}
diff -r deaf85acf6af -r a09622aaa043 src/mesh.h
--- a/src/mesh.h	Fri Jul 23 19:48:43 2010 +0100
+++ b/src/mesh.h	Sat Jul 24 06:28:17 2010 +0100
@@ -4,19 +4,19 @@
 #include <vector>
 
 struct Vertex {
-	float pos[3];
-	float normal[3];
+	float pos[4];
+	float normal[4];
 	float tex[2];
 };
 
 struct Face {
 	Vertex v[3];
-	float normal[3];
+	float normal[4];
 	int matid;
 };
 
 struct Material {
-	float kd[3], ks[3];
+	float kd[4], ks[4];
 	float kr, kt;
 	float spow;
 };
diff -r deaf85acf6af -r a09622aaa043 src/rt.cc
--- a/src/rt.cc	Fri Jul 23 19:48:43 2010 +0100
+++ b/src/rt.cc	Sat Jul 24 06:28:17 2010 +0100
@@ -3,21 +3,14 @@
 #include <math.h>
 #include <assert.h>
 #include "ocl.h"
+#include "mesh.h"
 
 struct RendInfo {
 	int xsz, ysz;
-	int num_sph, num_lights;
+	int num_faces, num_lights;
 	int max_iter;
 } __attribute__((packed));
 
-struct Sphere {
-	float pos[4];
-	float kd[4], ks[4];
-	float radius;
-	float spow;
-	float kr, kt;
-} __attribute__((packed));
-
 struct Ray {
 	float origin[4], dir[4];
 } __attribute__((packed));
@@ -32,9 +25,28 @@
 static CLProgram *prog;
 static int global_size;
 
-static Sphere sphlist[] = {
-	{{0, 0, 0, 1}, {0.7, 0.2, 0.15, 1}, {1, 1, 1, 1}, 1.0, 60, 0, 0},
-	{{-0.2, 0.4, -3, 1}, {0.2, 0.9, 0.3, 1}, {1, 1, 1, 1}, 0.25, 40, 0, 0}
+static Face faces[] = {
+	{/* face0 */
+		{
+			{{-1, 0, 0, 1}, {0, 0, -1, 1}, {0, 0}},
+			{{0, 1, 0, 1}, {0, 0, -1, 1}, {0, 0}},
+			{{1, 0, 0, 1}, {0, 0, -1, 1}, {0, 0}}
+		},
+		{0, 0, -1, 1}, 0
+	},
+	{/* face1 */
+		{
+			{{-5, 0, -3, 1}, {0, 0, -1, 1}, {0, 0}},
+			{{0, 0, 3, 1}, {0, 0, -1, 1}, {0, 0}},
+			{{5, 0, -3, 1}, {0, 0, -1, 1}, {0, 0}}
+		},
+		{0, 0, -1, 1}, 1
+	}
+};
+
+static Material matlib[] = {
+	{{1, 0, 0, 1}, {1, 1, 1, 1}, 0, 0, 60.0},
+	{{0.2, 0.8, 0.3, 1}, {0, 0, 0, 0}, 0, 0, 0}
 };
 
 static Light lightlist[] = {
@@ -53,7 +65,7 @@
 	// render info
 	rinf.xsz = xsz;
 	rinf.ysz = ysz;
-	rinf.num_sph = sizeof sphlist / sizeof *sphlist;
+	rinf.num_faces = sizeof faces / sizeof *faces;
 	rinf.num_lights = sizeof lightlist / sizeof *lightlist;
 	rinf.max_iter = 6;
 
@@ -75,10 +87,11 @@
 	/* setup argument buffers */
 	prog->set_arg_buffer(0, ARG_WR, xsz * ysz * 4 * sizeof(float), fb);
 	prog->set_arg_buffer(1, ARG_RD, sizeof rinf, &rinf);
-	prog->set_arg_buffer(2, ARG_RD, sizeof sphlist, sphlist);
-	prog->set_arg_buffer(3, ARG_RD, sizeof lightlist, lightlist);
-	prog->set_arg_buffer(4, ARG_RD, xsz * ysz * sizeof *prim_rays, prim_rays);
-	prog->set_arg_buffer(5, ARG_RD, sizeof xform, &xform);
+	prog->set_arg_buffer(2, ARG_RD, sizeof faces, faces);
+	prog->set_arg_buffer(3, ARG_RD, sizeof matlib, matlib);
+	prog->set_arg_buffer(4, ARG_RD, sizeof lightlist, lightlist);
+	prog->set_arg_buffer(5, ARG_RD, xsz * ysz * sizeof *prim_rays, prim_rays);
+	prog->set_arg_buffer(6, ARG_RD, sizeof xform, &xform);
 
 	global_size = xsz * ysz;
 	return true;
@@ -98,16 +111,13 @@
 
 	CLMemBuffer *mbuf = prog->get_arg_buffer(0);
 	map_mem_buffer(mbuf, MAP_RD);
-	/*if(!write_ppm("out.ppm", fb, xsz, ysz)) {
-		return 1;
-	}*/
 	unmap_mem_buffer(mbuf);
 	return true;
 }
 
 void set_xform(float *matrix)
 {
-	CLMemBuffer *mbuf = prog->get_arg_buffer(5);
+	CLMemBuffer *mbuf = prog->get_arg_buffer(6);
 	assert(mbuf);
 
 	assert(map_mem_buffer(mbuf, MAP_WR) == xform);