[FEATURE] simple GUI support

src/gui/gui_texture.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <glm/gtc/matrix_transform.hpp>
+
+namespace gui
+{
+	/*
+	 * Structure for representing a gui item to display on the screen
+	 *
+	 * texture  = The texture for the gui
+	 * position = The center position of the gui
+	 * scale    = The size (scale) of the gui
+	 */
+	struct GuiTexture
+	{
+		int texture;
+		glm::vec2 position;
+		glm::vec2 scale;
+	};
+}

src/main.cpp

@@ -74,6 +74,16 @@ int main(void)
 
     entities::Camera camera(glm::vec3(0, 0, 0), glm::vec3(0, 0, 0));
 
+
+	// GUI stuff
+    shaders::GuiShader gui_shader;
+    gui_shader.Init();
+	
+    std::vector<gui::GuiTexture> guis;
+    gui::GuiTexture gui = { render_engine::loader::LoadTexture("res/Mayo.png"), glm::vec2(0.5f, 0.5f), glm::vec2(0.25f, 0.25f) };
+    guis.push_back(gui);
+	
+	
 	// Main game loop
 	while (!glfwWindowShouldClose(window))
 	{
@@ -83,27 +93,33 @@ int main(void)
 
 		// Render
         render_engine::renderer::Prepare();
+		
         shader.Start();
         shader.LoadSkyColor(render_engine::renderer::SKY_COLOR);
         shader.LoadLights(lights);
         shader.LoadViewMatrix(camera);
 		
-        /**
+        // Renders each entity in the entities list
-        * renders eacht entitie in the entities list
-        **/
 		for (entities::Entity& entity : entities)
 		{
             render_engine::renderer::Render(entity, shader);
 		}
 
-		// Finish up
+		// Stop rendering the entities
         shader.Stop();
+
+		
+        // Render GUI items
+        render_engine::renderer::Render(guis, gui_shader);
+
+        // Finish up
 		glfwSwapBuffers(window);
 		glfwPollEvents();
 	}
 
 	// Clean up
     shader.CleanUp();
+    gui_shader.CleanUp();
     render_engine::loader::CleanUp();
 	glfwTerminate();
     return 0;

src/models/Model.h

@@ -15,7 +15,7 @@ namespace models
 	{
 		GLuint vao_id;
 		int vertex_count;
-		glm::vec3 model_size;
+		glm::vec3 model_size = { -1, -1, -1 };
 	};
 
 	/*

src/renderEngine/Loader.cpp

@@ -19,7 +19,7 @@ namespace render_engine
 		static std::vector<GLuint> textures;
 
 		/*
-			This function will generate a Model from vertex positions, textureCoordinates and indices.
+			This function will generate a Model from vertex positions, textureCoordinates normals and indices.
 		*/
 		models::RawModel LoadToVAO(std::vector<float>& positions, std::vector<float>& texture_coords, std::vector<float>& normals, std::vector<unsigned int>& indices)
 		{
@@ -35,6 +35,17 @@ namespace render_engine
 			return { vao_id, static_cast<int>(indices.size()), model_size };
 		}
 
+		/*
+			This function will generate a Model from vertex positions.
+		*/
+		models::RawModel LoadToVAO(std::vector<float>& positions)
+		{
+			const GLuint vao_id = CreateVao();
+			StoreDataInAttributeList(0, 2, positions);
+			glBindVertexArray(0);
+			return { vao_id, static_cast<int>(positions.size()) / 2 };
+		}
+
 		/*
 			Loads an image as texture into openGL
 		 */

src/renderEngine/Loader.h

@@ -9,24 +9,36 @@ namespace render_engine
 	namespace loader
 	{
 		/*
-			@brief: This function generates a model from model data.
+		*	@brief: This function generates a model from model data.
-
+		*
-			@param position: The positions of each vertex (in order: x, y, z) in the model
+		*	@param position: The positions of each vertex (in order: x, y, z) in the model
-			@param texture_coords: The texture coordinates of the model
+		*	@param texture_coords: The texture coordinates of the model
-			@param normals: The normals of each face of the model
+		*	@param normals: The normals of each face of the model
-			@param indices: A list with a sort of lookup table to the positions parameter
+		*	@param indices: A list with a sort of lookup table to the positions parameter
+		*
+		*	@return: A new rawmodel which represents al the parameters in one struct
 		*/
 		models::RawModel LoadToVAO(std::vector<float>& positions, std::vector<float>& texture_coords, std::vector<float>& normals, std::vector<unsigned int>& indices);
 
 		/*
-			@brief: Loads a texture from a file into openGL using stb_image.h
+		 * @brief: Overloaded function of the function above, but does not need normals and indices.
+		 *         Use this function to for example load GUI items to OpenGL.
+		 *
+		 * @param position: The positions of each vertex (in order: x, y, z) in the model
+		 *
+		 * @return: A new rawmodel which represents al the parameters in one struct
+		 */
+		models::RawModel LoadToVAO(std::vector<float>& positions);
 		
-			@param file_name: The filepath to the texture
+		/*
+		*	@brief: Loads a texture from a file into openGL using stb_image.h
+		*
+		*	@param file_name: The filepath to the texture
 		 */
 		GLuint LoadTexture(std::string file_name);
 		
 		/*
-			@brief: Call this function when cleaning up all the meshes (when exiting the program).
+		*	@brief: Call this function when cleaning up all the meshes (when exiting the program).
 		*/
 		void CleanUp();
 	}

src/renderEngine/Renderer.cpp

@@ -1,8 +1,11 @@
 #include <GL/glew.h>
 #include <glm/gtc/matrix_transform.hpp>
 #include "../models/model.h"
-#include "renderer.h"
+#include "loader.h"
 #include "../toolbox/toolbox.h"
+#include "renderer.h"
+
+#include <iostream>
 
 namespace render_engine
 {
@@ -12,9 +15,10 @@ namespace render_engine
 		static const float NEAR_PLANE = 0.01f;
 		static const float FAR_PLANE = 1000.0f;
 
-		/*
+		// GUI variables
-			This function will load the projectionMatrix into the shader
+		static models::RawModel quad;
-		 */
+		
+		
 		void Init(shaders::EntityShader& shader)
 		{
 			// Faces which are not facing the camera are not rendered
@@ -28,6 +32,10 @@ namespace render_engine
 			shader.Start();
 			shader.LoadProjectionMatrix(projectionMatrix);
 			shader.Stop();
+
+			// Initialize the quad for the GUI
+			std::vector<float> quad_positions = { -1, 1, -1, -1, 1, 1, 1, -1 };
+			quad = loader::LoadToVAO(quad_positions);
 		}
 
 		/*
@@ -49,7 +57,7 @@ namespace render_engine
 			const models::RawModel raw_model = model.raw_model;
 			const models::ModelTexture texture = model.texture;
 
-			// Enable the model
+			// Enable the model (VAO)
 			glBindVertexArray(raw_model.vao_id);
 
 			// Enable the VBO's from the model (VAO)
@@ -67,11 +75,52 @@ namespace render_engine
 			glBindTexture(GL_TEXTURE_2D, model.texture.texture_id);
 			glDrawElements(GL_TRIANGLES, raw_model.vertex_count, GL_UNSIGNED_INT, 0);
 
-			// Disable the VBO's and model
+			// Disable the VBO's and model (VAO)
 			glDisableVertexAttribArray(0);
 			glDisableVertexAttribArray(1);
 			glDisableVertexAttribArray(2);
 			glBindVertexArray(0);
 		}
+
+		void Render(std::vector<gui::GuiTexture>& guis, shaders::GuiShader& shader)
+		{
+			shader.Start();
+			
+			// Enable the VAO and the positions VBO
+			glBindVertexArray(quad.vao_id);
+			glEnableVertexAttribArray(0);
+
+			// Enable alpha blending (for transparency in the texture)
+			glEnable(GL_BLEND);
+			glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+			// Disable depth testing to textures with transparency can overlap
+			glDisable(GL_DEPTH_TEST);
+			
+			// Render each gui to the screen
+			for (gui::GuiTexture& gui : guis)
+			{
+				// Bind the texture of the gui to the shader
+				glActiveTexture(GL_TEXTURE0);
+				glBindTexture(GL_TEXTURE_2D, gui.texture);
+
+				glm::mat4 matrix = toolbox::CreateModelMatrix(gui.position, gui.scale);
+				shader.LoadModelMatrix(matrix);
+				
+				glDrawArrays(GL_TRIANGLE_STRIP, 0, quad.vertex_count);
+			}
+
+			// Enable depth test again
+			glEnable(GL_DEPTH_TEST);
+			
+			// Disable alpha blending
+			glDisable(GL_BLEND);
+			
+			// Disable the VBO and VAO
+			glDisableVertexAttribArray(0);
+			glBindVertexArray(0);
+
+			shader.Stop();
+		}
 	}
 }

src/renderEngine/Renderer.h

@@ -1,7 +1,9 @@
 #pragma once
 
+#include "../gui/gui_texture.h"
 #include "../entities/entity.h"
 #include "../shaders/entity_shader.h"
+#include "../shaders/gui_shader.h"
 
 namespace render_engine
 {
@@ -29,5 +31,13 @@ namespace render_engine
 			@param shader: The shader the entity needs to be rendered with
 		*/
 		void Render(entities::Entity& entity, shaders::EntityShader& shader);
+
+		/*
+			@brief: Call this function to render gui_textures on the screen
+
+			@param guis:  A list with all the GUI textures you want to render
+			@param shade: The shader the GUI textures need to be rendered with
+		 */
+		void Render(std::vector<gui::GuiTexture>& guis, shaders::GuiShader& shader);
 	}
 }

src/shaders/entity_shader.cpp

@@ -124,8 +124,7 @@ namespace shaders
 	
 	
 	EntityShader::EntityShader(): ShaderProgram(vertex_shader, fragment_shader)
-	{
+	{ }
-	}
 
 	void EntityShader::LoadModelMatrix(const glm::mat4& matrix) const
 	{

src/shaders/gui_shader.cpp

@@ -0,0 +1,57 @@
+#include "gui_shader.h"
+
+namespace shaders
+{
+	static std::string vertex_shader = R"(
+	#version 140
+
+	in vec2 position;
+
+	out vec2 texture_coords;
+
+	uniform mat4 model_matrix;
+
+	void main(void)
+	{
+		gl_Position = model_matrix * vec4(position, 0.0, 1.0);
+	
+		// This makes top left corner coordinate (0, 0) and bottom right (1, 1)
+		texture_coords = vec2((position.x + 1.0) / 2.0, 1 - (position.y + 1.0) / 2.0);
+	}
+	)";
+
+
+	static std::string fragment_shader = R"(
+	#version 140
+
+	in vec2 texture_coords;
+
+	out vec4 out_color;
+
+	uniform sampler2D gui_texture;
+
+	void main(void)
+	{
+		out_color = texture(gui_texture, texture_coords);
+	}
+	)";
+
+	
+	GuiShader::GuiShader() : ShaderProgram(vertex_shader, fragment_shader)
+	{ }
+
+	void GuiShader::LoadModelMatrix(const glm::mat4& matrix) const
+	{
+		LoadMatrix(location_model_matrix, matrix);
+	}
+
+	void GuiShader::SetAttributes() const
+	{
+		SetAttribute(0, "position");
+	}
+
+	void GuiShader::GetAllUniformLocations()
+	{
+		location_model_matrix = GetUniformLocation("model_matrix");
+	}
+}

src/shaders/gui_shader.h

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <glm/gtc/matrix_transform.hpp>
+#include "shader_program.h"
+
+namespace shaders
+{
+	/*
+	 * This class handles the shaders for all the GUI items
+	 */
+	
+	class GuiShader : public ShaderProgram
+	{
+	private:
+		GLuint location_model_matrix;
+
+	public:
+		GuiShader();
+
+		/*
+		 * @brief: A method to load the model matrix into the shader
+		 *
+		 * @param matrix: The model matrix
+		 */
+		void LoadModelMatrix(const glm::mat4& matrix) const;
+
+	protected:
+		void SetAttributes() const override;
+		void GetAllUniformLocations() override;
+	};
+}

src/toolbox/toolbox.cpp

@@ -2,6 +2,14 @@
 
 namespace toolbox
 {
+	glm::mat4 CreateModelMatrix(glm::vec2 translation, glm::vec2 scale)
+	{
+		glm::mat4 matrix(1.0f);
+		matrix = glm::translate(matrix, glm::vec3(translation.x, translation.y, 0));
+		matrix = glm::scale(matrix, glm::vec3(scale.x, scale.y, 0));
+		return matrix;
+	}
+
 	glm::mat4 CreateModelMatrix(glm::vec3 translation, glm::vec3 rotation, float scale)
 	{
 		glm::mat4 matrix(1.0f);

src/toolbox/toolbox.h

@@ -8,6 +8,16 @@ namespace toolbox
 	#define WINDOW_WIDTH 1400.0f
 	#define WINDOW_HEIGT 800.0f
 
+	/*
+	 * @brief: This function will create a model matrix
+	 *
+	 * @param translation: The position of the model
+	 * @param scale: The scale of the model
+	 *
+	 * @return: The model matrix of the model
+	 */
+	glm::mat4 CreateModelMatrix(glm::vec2 translation, glm::vec2 scale);
+	
 	/*
 	 * @brief: This function will create a model matrix
 	 *

wk2_fps.vcxproj

@@ -25,6 +25,7 @@
     <ClCompile Include="src\renderEngine\loader.cpp" />
     <ClCompile Include="src\renderEngine\obj_loader.cpp" />
     <ClCompile Include="src\renderEngine\renderer.cpp" />
+    <ClCompile Include="src\shaders\gui_shader.cpp" />
     <ClCompile Include="src\shaders\shader_program.cpp" />
     <ClCompile Include="src\shaders\entity_shader.cpp" />
     <ClCompile Include="src\toolbox\toolbox.cpp" />
@@ -33,10 +34,12 @@
     <ClInclude Include="src\entities\camera.h" />
     <ClInclude Include="src\entities\entity.h" />
     <ClInclude Include="src\entities\light.h" />
+    <ClInclude Include="src\gui\gui_texture.h" />
     <ClInclude Include="src\models\model.h" />
     <ClInclude Include="src\renderEngine\loader.h" />
     <ClInclude Include="src\renderEngine\obj_loader.h" />
     <ClInclude Include="src\renderEngine\renderer.h" />
+    <ClInclude Include="src\shaders\gui_shader.h" />
     <ClInclude Include="src\shaders\shader_program.h" />
     <ClInclude Include="src\shaders\entity_shader.h" />
     <ClInclude Include="src\stb_image.h" />

wk2_fps.vcxproj.filters

@@ -42,6 +42,9 @@
     <ClCompile Include="src\shaders\entity_shader.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="src\shaders\gui_shader.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="src\entities\Camera.h">
@@ -77,5 +80,11 @@
     <ClInclude Include="src\shaders\entity_shader.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="src\gui\gui_texture.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="src\shaders\gui_shader.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>