From 1b0cc1d80b937732362395eceafc68909545fd67 Mon Sep 17 00:00:00 2001
From: FakeShemp <sakcheen@gmail.com>
Date: Fri, 22 Jan 2016 16:41:20 +0100
Subject: [PATCH] Add normal map support

---
 assets                                   |  2 +-
 include/Engine/Rendering/DrawFinalPass.h |  1 +
 resources/Shaders/ForwardPlus.frag.glsl  | 15 ++++++++++++---
 resources/Shaders/ForwardPlus.vert.glsl  |  4 ++++
 src/Engine/Rendering/DrawFinalPass.cpp   | 10 ++++++++++
 5 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/assets b/assets
index 6ffb46e1..f7e349a3 160000
--- a/assets
+++ b/assets
@@ -1 +1 @@
-Subproject commit 6ffb46e155c8f013241cd1507098c94900ec2448
+Subproject commit f7e349a3166eee5706a9262b7d36e45a1cb73e80
diff --git a/include/Engine/Rendering/DrawFinalPass.h b/include/Engine/Rendering/DrawFinalPass.h
index 20c7249d..01c7d473 100644
--- a/include/Engine/Rendering/DrawFinalPass.h
+++ b/include/Engine/Rendering/DrawFinalPass.h
@@ -27,6 +27,7 @@ private:
     void GenerateTexture(GLuint* texture, GLenum wrapping, GLenum filtering, glm::vec2 dimensions, GLint internalFormat, GLint format, GLenum type) const;
 
     Texture* m_WhiteTexture;
+	Texture* m_NeutralNormalMap;
 
     const IRenderer* m_Renderer;
     const LightCullingPass* m_LightCullingPass;
diff --git a/resources/Shaders/ForwardPlus.frag.glsl b/resources/Shaders/ForwardPlus.frag.glsl
index 78a2125e..8625413a 100644
--- a/resources/Shaders/ForwardPlus.frag.glsl
+++ b/resources/Shaders/ForwardPlus.frag.glsl
@@ -5,7 +5,8 @@ uniform mat4 V;
 uniform mat4 P;
 uniform vec4 Color;
 uniform vec2 ScreenDimensions;
-uniform sampler2D texture0;
+layout(binding = 0) uniform sampler2D DiffuseTexture;
+layout(binding = 1) uniform sampler2D NormalMapTexture;
 
 #define TILE_SIZE 16
 
@@ -44,6 +45,8 @@ layout (std430, binding = 4) buffer LightIndexBuffer
 in VertexData{
 	vec3 Position;
 	vec3 Normal;
+	vec3 Tangent;
+	vec3 BiTangent;
 	vec2 TextureCoordinate;
 	vec4 DiffuseColor;
 }Input;
@@ -96,12 +99,18 @@ LightResult CalcDirectionalLightSource(vec4 direction, vec4 color, float intensi
 	return result;
 }
 
+vec4 CalcNormalMappedValue(vec3 normal, vec3 tangent, vec3 bitangent, vec2 textureCoordinate, sampler2D normalMap)
+{
+	mat3 TBN = mat3(tangent, bitangent, normal);
+	vec3 NormalMap = texture(normalMap, textureCoordinate).xyz * 2.0 - vec3(1.0);
+	return vec4(TBN * normalize(NormalMap), 0.0);
+}
 
 void main()
 {
-	vec4 texel = texture2D(texture0, Input.TextureCoordinate);
+	vec4 texel = texture2D(DiffuseTexture, Input.TextureCoordinate);
 	vec4 position = V * M * vec4(Input.Position, 1.0); 
-	vec4 normal = V  * vec4(Input.Normal, 0.0);
+	vec4 normal = V * CalcNormalMappedValue(Input.Normal, Input.Tangent, Input.BiTangent, Input.TextureCoordinate, NormalMapTexture);
 	vec4 viewVec = normalize(-position); 
 
 	vec2 tilePos;
diff --git a/resources/Shaders/ForwardPlus.vert.glsl b/resources/Shaders/ForwardPlus.vert.glsl
index d3b8ba16..038b147c 100644
--- a/resources/Shaders/ForwardPlus.vert.glsl
+++ b/resources/Shaders/ForwardPlus.vert.glsl
@@ -19,6 +19,8 @@ layout(location = 10) in vec4 BoneWeights2;
 out VertexData{
 	vec3 Position;
 	vec3 Normal;
+	vec3 Tangent;
+	vec3 BiTangent;
 	vec2 TextureCoordinate;
 	vec4 DiffuseColor;
 }Output;
@@ -30,5 +32,7 @@ void main()
 	Output.Position = Position;
 	Output.TextureCoordinate = TextureCoords;
 	Output.Normal = vec3(M * vec4(Normal, 0.0));
+	Output.Tangent = vec3(M * vec4(Tangent, 0.0));
+	Output.BiTangent = vec3(M * vec4(BiTangent, 0.0));
 	Output.DiffuseColor = DiffuseVertexColor;
 }
\ No newline at end of file
diff --git a/src/Engine/Rendering/DrawFinalPass.cpp b/src/Engine/Rendering/DrawFinalPass.cpp
index eeaa7bb3..98913079 100644
--- a/src/Engine/Rendering/DrawFinalPass.cpp
+++ b/src/Engine/Rendering/DrawFinalPass.cpp
@@ -11,6 +11,7 @@ DrawFinalPass::DrawFinalPass(IRenderer* renderer, LightCullingPass* lightCulling
 void DrawFinalPass::InitializeTextures()
 {
     m_WhiteTexture = ResourceManager::Load<Texture>("Textures/Core/Blank.png");
+	m_NeutralNormalMap = ResourceManager::Load<Texture>("Textures/Core/NeutralNormalMap.png");
 }
 
 void DrawFinalPass::InitializeShaderPrograms()
@@ -59,6 +60,15 @@ void DrawFinalPass::Draw(RenderScene& scene)
                 glBindTexture(GL_TEXTURE_2D, m_WhiteTexture->m_Texture);
             }
 
+			if (modelJob->NormalTexture != nullptr) {
+				glActiveTexture(GL_TEXTURE1);
+				glBindTexture(GL_TEXTURE_2D, modelJob->NormalTexture->m_Texture);
+			}
+			else {
+				glActiveTexture(GL_TEXTURE1);
+				glBindTexture(GL_TEXTURE_2D, m_NeutralNormalMap->m_Texture);
+			}
+
             glBindVertexArray(modelJob->Model->VAO);
             glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, modelJob->Model->ElementBuffer);
             glDrawElementsBaseVertex(GL_TRIANGLES, modelJob->EndIndex - modelJob->StartIndex + 1, GL_UNSIGNED_INT, 0, modelJob->StartIndex);