X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=demo_prior;a=blobdiff_plain;f=sdr%2Fwhitted.p.glsl;h=368903d5a16748ac06e2cbd19a80bf9b51f10ed4;hp=fc197f67e42b429e3985da2b608e33ada9e37205;hb=44a7a61d2bec54ed741930572e63e5015326daca;hpb=ec776ad8bf37d25b9308e2c770d66247135b46ea

diff --git a/sdr/whitted.p.glsl b/sdr/whitted.p.glsl
index fc197f6..368903d 100644
--- a/sdr/whitted.p.glsl
+++ b/sdr/whitted.p.glsl
@@ -23,6 +23,11 @@ bool isect_plane(in vec3 ro, in vec3 rd, in vec4 plane, out HitPoint hit);
 bool isect_sphere(in vec3 ro, in vec3 rd, in vec3 pos, float rad, out HitPoint hit);
 
 
+const Material mtl_sph = Material(vec3(1.0, 0.0, 0.0), vec3(1.0, 1.0, 1.0), 80.0);
+const Material mtl_floor = Material(vec3(0.5, 0.5, 0.5), vec3(0.0, 0.0, 0.0), 1.0);
+
+const vec3 light_pos = vec3(-20, 20, 30);
+
 void main()
 {
 	vec3 rdir = normalize(v_rdir);
@@ -39,7 +44,22 @@ void main()
 
 vec3 shade(in vec3 ro, in vec3 rd, in HitPoint hit)
 {
-	return (hit.norm * 0.5 + 0.5) * hit.mtl.diffuse;
+	HitPoint shadow_hit;
+	vec3 ldir = light_pos - hit.pos;
+
+	vec3 col = vec3(0.03, 0.03, 0.03);	// ambient
+
+	if(!isect_scene(hit.pos + hit.norm * 0.01, ldir, shadow_hit) || shadow_hit.dist > 1.0) {
+		vec3 l = normalize(ldir);
+		vec3 v = normalize(-rd);
+		vec3 h = normalize(v + l);
+		float ndotl = max(dot(hit.norm, l), 0.0);
+		float ndoth = max(dot(hit.norm, h), 0.0);
+
+		col += hit.mtl.diffuse * ndotl + hit.mtl.specular * pow(ndoth, hit.mtl.shin);
+	}
+
+	return col;
 }
 
 #define M_PI	3.1415926
@@ -50,9 +70,6 @@ vec3 backdrop(in vec3 dir)
 	return mix(vec3(0.8, 0.3, 0.2), vec3(0.2, 0.3, 0.8), smoothstep(-0.1, 0.1, dir.y));
 }
 
-const Material mtl_sph = Material(vec3(1.0, 0.0, 0.0), vec3(1.0, 1.0, 1.0), 80.0);
-const Material mtl_floor = Material(vec3(0.5, 0.5, 0.5), vec3(0.0, 0.0, 0.0), 1.0);
-
 bool isect_scene(in vec3 ro, in vec3 rd, out HitPoint hit_res)
 {
 	HitPoint hit, nearest;
@@ -77,15 +94,18 @@ bool isect_scene(in vec3 ro, in vec3 rd, out HitPoint hit_res)
 	return true;
 }
 
+#define FLOOR_OFFS	vec3(2.0, 0.0, 0.0)
+
 bool isect_floor(in vec3 ro, in vec3 rd, float rad, out HitPoint hit)
 {
-	if(!isect_plane(ro, rd, vec4(0.0, 1.0, 0.0, -1.0), hit)) {
+	if(!isect_plane(ro - FLOOR_OFFS, rd, vec4(0.0, 1.0, 0.0, -1.0), hit)) {
 		return false;
 	}
 
 	float d = max(abs(hit.pos.x), abs(hit.pos.z));
 	if(d >= rad) return false;
 
+	hit.pos += FLOOR_OFFS;
 	return true;
 }
 
@@ -101,6 +121,10 @@ bool isect_plane(in vec3 ro, in vec3 rd, in vec4 plane, out HitPoint hit)
 	vec3 pdir = pp - ro;
 	float t = dot(pdir, plane.xyz) / ndotrd;
 
+	if(t < 1e-6) {
+		return false;
+	}
+
 	hit.dist = t;
 	hit.pos = ro + rd * t;
 	hit.norm = plane.xyz;