From 840a1e861fea17905b33c155d1c0d15580dfe17c Mon Sep 17 00:00:00 2001
From: Joshua Goins <josh@redstrate.com>
Date: Tue, 15 Feb 2022 09:02:42 -0500
Subject: [PATCH] Add back support for normal textures in material compiler

---
 engine/renderer/src/materialcompiler.cpp | 25 +++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/engine/renderer/src/materialcompiler.cpp b/engine/renderer/src/materialcompiler.cpp
index a2e8c2d..34a97fb 100755
--- a/engine/renderer/src/materialcompiler.cpp
+++ b/engine/renderer/src/materialcompiler.cpp
@@ -215,7 +215,13 @@ ShaderSource MaterialCompiler::compile_material_fragment(Material& material, boo
 
         src += "layout(binding = " + std::to_string(sampler_index++) + ") uniform sampler2D colorTexture;\n";
     }
-    
+
+    if(material.normalProperty.type == DataType::AssetTexture) {
+        material.bound_textures[sampler_index] = material.normalProperty.value_tex;
+
+        src += "layout(binding = " + std::to_string(sampler_index++) + ") uniform sampler2D normalTexture;\n";
+    }
+
     if(use_ibl) {
         src += "vec3 get_reflect(int i, vec3 final_normal) {\n \
         const vec3 direction = normalize(in_frag_pos - scene.camPos.xyz);\n \
@@ -292,7 +298,16 @@ ShaderSource MaterialCompiler::compile_material_fragment(Material& material, boo
     src += "vec3 final_diffuse_color =  from_srgb_to_linear(Color);\n";
     src += "float final_roughness = scene.materials[inMaterialIndex].info.y;\n";
     src += "float final_metallic = scene.materials[inMaterialIndex].info.x;\n";
-    src += "vec3 final_normal = in_normal;\n";
+
+    if(material.normalProperty.type == DataType::AssetTexture) {
+        prism::log("enabling normal mapping on material..");
+
+        src += "vec3 final_normal = texture(normalTexture, in_uv).rgb;\n";
+        src += "final_normal = final_normal * 2.0 - 1.0;\n";
+        src += "final_normal = in_tbn * final_normal;\n";
+    } else {
+        src += "vec3 final_normal = in_normal;\n";
+    }
     
     src +=
     "ComputedSurfaceInfo surface_info = compute_surface(final_diffuse_color.rgb, final_normal, final_metallic, final_roughness);\n \
@@ -312,7 +327,11 @@ ShaderSource MaterialCompiler::compile_material_fragment(Material& material, boo
                 break;\n \
         }\n \
     SurfaceBRDF surface_brdf = brdf(light_info.direction, surface_info);\n";
-        
+
+    if(render_options.enable_normal_mapping && material.normalProperty.type == DataType::AssetTexture && render_options.enable_normal_shadowing) {
+        src += std::string("light_info.radiance *= calculate_normal_lighting(normalTexture, final_normal, light_info.direction);\n");
+    }
+
     src += "Lo += ((surface_brdf.specular + surface_brdf.diffuse) * light_info.radiance * surface_brdf.NdotL) * scene.lights[i].colorSize.rgb;\n \
     }\n";