basic pbr

5 files changed, 65 insertions, 22 deletions

diff --git a/c2.cpp b/c2.cpp
index 32a0d41..b19c238 100644
--- a/c2.cpp
+++ b/c2.cpp
@@ -429,19 +429,19 @@ extern "C" int entrypoint() {
 		monkey->transform = m4f::translate(
 			m4f::identity(),
 			v3f(0.0f, 0.0f, 0.0f)
-		)/* * m4f::rotate(
+		) * m4f::rotate(
 			m4f::identity(),
 			rot,
 			raxis
-		)*/;
+		);
 		monkey2->transform = m4f::translate(
 			m4f::identity(),
 			v3f(2.0f, 0.0f, 2.0f)
-		)/* * m4f::rotate(
+		) * m4f::rotate(
 			m4f::identity(),
 			rot * 2.0f,
 			v3f(1.0f, 0.0f, 0.0f)
-		)*/;
+		);
 		camera.asp = (float)bb.w / (float)bb.h;
 		camera.update(*app);
 		scene.update(camera, dev);
@@ -469,7 +469,7 @@ extern "C" int entrypoint() {
 		ctx.debug_pop();
 
 		r += 10;
-		rot += 5.0f * app->dt;
+		rot += 1.0f * app->dt;
 		frame++;
 		dev->present();
 		app->end();
diff --git a/intermediate/bricks.mat b/intermediate/bricks.mat
index 28bea24..1ed5535 100644
--- a/intermediate/bricks.mat
+++ b/intermediate/bricks.mat
@@ -1,6 +1,6 @@
 [params]
 metalness: 1.0
-roughness: 1.0
+roughness: 0.3
 ao: 1.0
 albedo: ffffff
 
diff --git a/intermediate/plastic.mat b/intermediate/plastic.mat
index ff71d8b..3d59385 100644
--- a/intermediate/plastic.mat
+++ b/intermediate/plastic.mat
@@ -1,6 +1,6 @@
 [params]
 metalness: 0.0
-roughness: 0.0
+roughness: 0.1
 ao: 1.0
 albedo: ff0000
 
diff --git a/intermediate/surface.glsl b/intermediate/surface.glsl
index 0f55016..2d5d470 100644
--- a/intermediate/surface.glsl
+++ b/intermediate/surface.glsl
@@ -27,9 +27,6 @@ type: vec2
 name: position
 type: vec4
 [interpolator]
-name: normal
-type: vec3
-[interpolator]
 name: tbn
 type: mat3
 
@@ -56,6 +53,9 @@ type: float
 [variable]
 name: ao
 type: float
+[variable]
+name: camera_pos
+type: vec3
 
 [cbuffer]
 name: c_mvp
@@ -101,7 +101,6 @@ void main() {
 	vec3 t = normalize((c_mvp.model * vec4(tangent, 0.0)).xyz);
 	vec3 n = normalize((c_mvp.model * vec4(normal, 0.0)).xyz);
 	vec3 b = cross(t, n);
-	interpolator.normal = n;
 	interpolator.tbn = mat3(t, b, n);
 	interpolator.uv = uv;
 	interpolator.position = pos;
@@ -113,23 +112,62 @@ void main() {
 
 #ifdef FRAGMENT_SHADER
 
+#define pi 3.14159265358979323846
+
+vec3 diffuse_brdf(vec2 uv) {
+	vec3 a = material.albedo * texture(albedo, uv).rgb;
+	return a / pi;
+}
+
+float specular_G1(float a, vec3 v, vec3 n) {
+	float ndv = max(dot(n, v), 0.0);
+	float a1 = a + 1.0;
+	float k = (a1 * a1) / 8.0;
+	return ndv / (ndv * (1.0 - k) + k);
+}
+
+float specular_brdf(vec2 uv, vec3 l, vec3 v, vec3 n) {
+	float ndl = max(dot(n, l), 0.0);
+	float ndv = max(dot(n, v), 0.0);
+	vec3 ref = reflect(-l, n);  
+	float a = texture(rough, uv).r * material.roughness;
+	float a2 = a * a;
+	float ndr = max(dot(n, ref), 0.0);
+	float b = ((ndr * ndr) * (a2 - 1) + 1);
+	float D =
+		a2 / (pi * b * b);
+	float G = specular_G1(a, l, n) * specular_G1(a, v, n);
+	float F0 = G;
+	float F = F0 + (1.0 - F0) *
+		pow(2, ((-5.55473 * ndr - 6.98316), ndr));
+	return (D * F * G) / (4.0 * ndl * ndv);
+}
+
 void main() {
 	vec2 uv = interpolator.uv;
+	vec3 p = interpolator.position.xyz;
 
 	vec3 nrmsample = texture(normal, uv).rgb;
-
 	vec2 nrmxy = nrmsample.xy * 2.0 - 1.0;
 	vec3 nrm = normalize(vec3(nrmxy, 1.0));
 	if (nrmsample.b == 1.0) /* default texture */
-		nrm = vec3(0, 0, 1);
-	nrm = normalize(interpolator.tbn * nrm);
-
-	float light = max(dot(nrm, vec3(0, 0, 1)), 0.0);
-
-	vec3 ambient = 0.05.xxx * texture(ao, uv).r;
-	vec3 col = ambient + light * material.albedo;
-	col *= texture(albedo, uv).rgb;
-	colour = vec4(col, 1.0);
+		nrm = normalize(interpolator.tbn[2]);
+	else
+		nrm = normalize(interpolator.tbn * nrm);
+
+	vec3 light_dir = vec3(0, 0, 1);
+	vec3 col = texture(albedo, uv).rgb * material.albedo;
+	float cos_theta_i = max(dot(nrm, light_dir), 0.0);
+	vec3 view_dir = normalize(material.camera_pos - p);
+
+	vec3 diffuse =
+		diffuse_brdf(uv) *
+		cos_theta_i;
+	float spec =
+		specular_brdf(uv, light_dir, view_dir, nrm) *
+		cos_theta_i;
+
+	colour = vec4(diffuse + vec3(spec), 1.0);
 }
 
 #endif
diff --git a/model.cpp b/model.cpp
index 4c5edcc..778d945 100644
--- a/model.cpp
+++ b/model.cpp
@@ -20,7 +20,9 @@ struct Mat_Cbuffer {
 	float metalness;
 	float roughness;
 	float ao;
-	char pad[40];
+	char pad2[8];
+	float camera_pos[3];
+	char pad[20];
 };
 
 void Material::use(
@@ -316,6 +318,9 @@ void Model_Instance::update_cbuffers(
 		mat.metalness = sm.metalness;
 		mat.roughness = sm.roughness;
 		mat.ao = sm.ao;
+		mat.camera_pos[0] = cam.position.x;
+		mat.camera_pos[1] = cam.position.y;
+		mat.camera_pos[2] = cam.position.z;
 	}
 	dev->unmap_buffer(mvp);
 	dev->unmap_buffer(mat);