From d26100734623f37063206b9b144c2a29fd71d414 Mon Sep 17 00:00:00 2001
From: quou <quou@disroot.org>
Date: Wed, 1 Jan 2025 18:43:31 +1100
Subject: material system

---
 intermediate/surface.glsl | 83 ++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 75 insertions(+), 8 deletions(-)

(limited to 'intermediate/surface.glsl')

diff --git a/intermediate/surface.glsl b/intermediate/surface.glsl
index 18c13a3..7988502 100644
--- a/intermediate/surface.glsl
+++ b/intermediate/surface.glsl
@@ -14,6 +14,9 @@ type: vec3
 name: normal
 type: vec3
 [attribute]
+name: tangent
+type: vec3
+[attribute]
 name: uv
 type: vec2
 
@@ -21,8 +24,14 @@ type: vec2
 name: uv
 type: vec2
 [interpolator]
+name: position
+type: vec4
+[interpolator]
 name: normal
 type: vec3
+[interpolator]
+name: tbn
+type: mat3
 
 [struct]
 name: MVP
@@ -33,11 +42,52 @@ type: mat4
 name: view_projection
 type: mat4
 
+[struct]
+name: Material
+[variable]
+name: albedo
+type: vec3
+[variable]
+name: metalness
+type: float
+[variable]
+name: roughness
+type: float
+[variable]
+name: ao
+type: float
+
 [cbuffer]
 name: c_mvp
 type: MVP
 stage: vertex
 
+[cbuffer]
+name: material
+type: Material
+stage: fragment
+
+[texture]
+name: albedo
+stage: fragment
+dimension: 2
+[texture]
+name: ao
+stage: fragment
+dimension: 2
+[texture]
+name: metal
+stage: fragment
+dimension: 2
+[texture]
+name: rough
+stage: fragment
+dimension: 2
+[texture]
+name: normal
+stage: fragment
+dimension: 2
+
 [target]
 name: colour
 type: vec4
@@ -47,12 +97,16 @@ type: vec4
 #ifdef VERTEX_SHADER
 
 void main() {
+	vec4 pos = c_mvp.model * vec4(position, 1.0);
+	vec3 t = normalize((c_mvp.model * vec4(tangent, 0.0)).xyz);
+	vec3 b = normalize((c_mvp.model * vec4(normal, 0.0)).xyz);
+	vec3 n = normalize((c_mvp.model * vec4(cross(normal, tangent), 0.0)).xyz);
+	interpolator.normal = n;
+	interpolator.tbn = mat3(t, b, n);
 	interpolator.uv = uv;
-	interpolator.normal = mat3(c_mvp.model) * normal;
-	gl_Position =
-		c_mvp.view_projection *
-		c_mvp.model *
-		vec4(position, 1.0);
+	interpolator.position = pos;
+	interpolator.tbn = mat3(t, b, n);
+	gl_Position = c_mvp.view_projection * pos;
 }
 
 #endif
@@ -60,9 +114,22 @@ void main() {
 #ifdef FRAGMENT_SHADER
 
 void main() {
-	vec3 normal = normalize(interpolator.normal);
-	float light = max(dot(normal, vec3(0, 0, 1)), 0.0);
-	colour = vec4(light.xxx, 1.0);
+	vec2 uv = interpolator.uv;
+
+	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 = light * material.albedo;
+	col *= texture(albedo, uv).rgb;
+	colour = vec4(col, 1.0);
 }
 
 #endif
-- 
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