Allow to use opacity texture

Author: kmarkindev

assets/shaders/basic_fragment.frag

@@ -14,6 +14,8 @@ uniform vec3 CameraPos;
 
 uniform sampler2D diffuseTexture;
 uniform sampler2D specularTexture;
+uniform sampler2D opacityTexture;
+uniform bool UseOpacity;
 
 void main()
 {
@@ -41,5 +43,12 @@ void main()
 		specular = specularStrength * spec * LightColor;
 	}
 
-	color = vec4((ambient + diffuse + specular) * objectColor, 1.0f);
+	float opacity = 1.f;
+
+	if(UseOpacity)
+	{
+		opacity = texture(opacityTexture, texCoords).x;
+	}
+
+	color = vec4((ambient + diffuse + specular) * objectColor, opacity);
 }

src/Application.cpp

@@ -226,6 +226,22 @@ void Application::DrawImguiUi()
             if(ImGui::Button("Load specular"))
                 ImGuiFileDialog::Instance()
                     ->OpenDialog("ChooseSpecular", "Choose specular texture", ".png,.jpg,.jpeg", ".");
+
+            ImGui::Image((void*)(intptr_t)m_model->GetMaterial()->opacity.id, {128, 128});
+
+            ImGui::SameLine();
+
+            if(ImGui::Button("Load opacity"))
+                ImGuiFileDialog::Instance()
+                    ->OpenDialog("ChooseOpacity", "Choose opacity texture", ".png,.jpg,.jpeg", ".");
+
+            ImGui::SameLine();
+
+            bool useOpacity = m_model->GetUseOpacity();
+            if(ImGui::Checkbox("Use opacity", &useOpacity))
+            {
+                m_model->UseOpacity(useOpacity);
+            }
         }
     }
 
@@ -262,6 +278,17 @@ void Application::DrawImguiUi()
         ImGuiFileDialog::Instance()->Close();
     }
 
+     if (ImGuiFileDialog::Instance()->Display("ChooseOpacity")) 
+    {
+        if (ImGuiFileDialog::Instance()->IsOk())
+        {
+            std::string path = ImGuiFileDialog::Instance()->GetFilePathName();
+            LoadTexture(path, TextureType::Opacity);
+        }
+    
+        ImGuiFileDialog::Instance()->Close();
+    }
+
     if(ImGui::CollapsingHeader("Actions"))
     {
         if (ImGui::Button("Reset camera position"))

src/Material.cpp

@@ -4,6 +4,7 @@ void Material::UnloadMaterial()
 {
     specular.Unload();
     diffuse.Unload();
+    opacity.Unload();
 }
 
 void Material::ReplaceTexture(Texture newTexture, TextureType type) 
@@ -17,6 +18,9 @@ void Material::ReplaceTexture(Texture newTexture, TextureType type)
     case TextureType::Specular:
         texture = &specular;
         break;
+    case TextureType::Opacity:
+        texture = &opacity;
+        break;
     default:
         throw NotImplementedException();
     }

src/Material.h

@@ -8,6 +8,7 @@ struct Material
 {
 	Texture diffuse;
 	Texture specular;
+	Texture opacity;
 
 	void UnloadMaterial();
 	void ReplaceTexture(Texture newTexture, TextureType type);

src/Model.cpp

@@ -25,6 +25,16 @@ void Model::SetShader(Shader* shader)
 	m_shader = shader;
 }
 
+void Model::UseOpacity(bool status) 
+{
+	m_useOpacity = status;
+}
+
+bool Model::GetUseOpacity() 
+{
+	return m_useOpacity;
+}
+
 void Model::Unload() 
 {
 	// m_material->UnloadMaterial();

src/Model.h

@@ -17,6 +17,7 @@ class Model : public Object
 	Shader* m_shader;
 	Material* m_material;
 	std::vector<Mesh>* m_meshes;
+	bool m_useOpacity = false;
 
 public:
 
@@ -27,6 +28,9 @@ class Model : public Object
 	void SetMaterial(Material* material);
 	void SetShader(Shader* shader);
 
+	void UseOpacity(bool status);
+	bool GetUseOpacity();
+
 	void Unload();
 
 };

src/Renderer.cpp

@@ -31,16 +31,21 @@ void Renderer::Draw(Model* model, Camera* camera, DirLight* light)
 	shader->SetVec3Uniform("LightDir", light->GetForwardVector());
 	shader->SetVec3Uniform("LightColor", light->color);
 	shader->SetFloatUniform("LightShiness", light->shiness);
+	shader->SetBoolUniform("UseOpacity", model->m_useOpacity);
 
 	shader->SetIntUniform("diffuseTexture", 0);
 	shader->SetIntUniform("specularTexture", 1);
+	shader->SetIntUniform("opacityTexture", 2);
 
 	glActiveTexture(GL_TEXTURE0);
 	glBindTexture(GL_TEXTURE_2D, model->m_material->diffuse.id);
 
 	glActiveTexture(GL_TEXTURE1);
 	glBindTexture(GL_TEXTURE_2D, model->m_material->specular.id);
 
+	glActiveTexture(GL_TEXTURE2);
+	glBindTexture(GL_TEXTURE_2D, model->m_material->opacity.id);
+
 	for (Mesh mesh : model->m_meshes[0])
 	{
 		glBindVertexArray(mesh.m_meshData.vao);
@@ -53,6 +58,9 @@ void Renderer::Draw(Model* model, Camera* camera, DirLight* light)
 
 	glActiveTexture(GL_TEXTURE1);
 	glBindTexture(GL_TEXTURE_2D, 0);
+
+	glActiveTexture(GL_TEXTURE2);
+	glBindTexture(GL_TEXTURE_2D, 0);
 }
 
 void Renderer::Shutdown()

src/Texture.h

@@ -5,7 +5,8 @@
 enum class TextureType
 {
 	Diffuse,
-	Specular
+	Specular,
+	Opacity
 };
 
 struct Texture