[ADD] custom rendering system

2021-05-18 11:20:57 +02:00
parent e46e26c729
commit 0bb4cc5e1d
29 changed files with 8840 additions and 805 deletions
--- a/src/renderEngine/Loader.cpp
+++ b/src/renderEngine/Loader.cpp
@@ -0,0 +1,118 @@
+#include <GL/glew.h>
+#include <GLFW/glfw3.h>
+#include "../stb_image.h"
+#include "Loader.h"
+
+namespace renderEngine
+{
+	namespace loader
+	{
+		static GLuint createVAO();
+		static void storeDataInAttributeList(int attributeNumber, int coordinateSize, std::vector<float>& data);
+		static void bindIndicesBuffer(std::vector<unsigned int>& indices);
+
+		static std::vector<GLuint> vaos;
+		static std::vector<GLuint> vbos;
+		static std::vector<GLuint> textures;
+
+		/*
+			This function will generate a Model from vertex positions, textureCoordinates and indices.
+		*/
+		struct models::RawModel LoadToVAO(std::vector<float>& positions, std::vector<float>& textureCoords, std::vector<unsigned int>& indices)
+		{
+			GLuint vaoID = createVAO();
+			bindIndicesBuffer(indices);
+			storeDataInAttributeList(0, 3, positions);
+			storeDataInAttributeList(1, 2, textureCoords);
+			glBindVertexArray(0);
+			return { vaoID, static_cast<int>(indices.size()) };
+		}
+
+		/*
+			Loads an image as texture into openGL
+		 */
+		GLuint LoadTexture(std::string fileName)
+		{
+			int width, height, bpp;
+			unsigned char* imgData = stbi_load(fileName.c_str(), &width, &height, &bpp, 4);
+
+			GLuint textureID;
+			glGenTextures(1, &textureID);
+			glEnable(GL_TEXTURE_2D);
+			glBindTexture(GL_TEXTURE_2D, textureID);
+			glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, imgData);
+			glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+			glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+			
+			stbi_image_free(imgData);
+			textures.push_back(textureID);
+			return textureID;
+		}
+
+		/*
+			This function will delete all the vectors declared at the top of this file from openGL.
+		*/
+		void CleanUp()
+		{
+			glDeleteVertexArrays(static_cast<GLsizei>(vaos.size()), &vaos[0]);
+			glDeleteBuffers(static_cast<GLsizei>(vbos.size()), &vbos[0]);
+			glDeleteTextures(static_cast<GLsizei>(textures.size()), &textures[0]);
+		}
+
+		/*
+			This function will create a new VAO for a new mesh.
+		*/
+		static GLuint createVAO()
+		{
+			GLuint vaoID;
+			glGenVertexArrays(1, &vaoID);
+			vaos.push_back(vaoID);
+			glBindVertexArray(vaoID);
+			return vaoID;
+		}
+
+		/*
+			This function can store data (vbo) in a vao.
+		*/
+		static void storeDataInAttributeList(int attributeNumber, int coordinateSize, std::vector<float>& data)
+		{
+			GLuint vboID;
+			glGenBuffers(1, &vboID);
+			vbos.push_back(vboID);
+			glBindBuffer(GL_ARRAY_BUFFER, vboID);
+			glBufferData(GL_ARRAY_BUFFER, sizeof(float) * data.size(), &data[0], GL_STATIC_DRAW);
+			glVertexAttribPointer(attributeNumber, coordinateSize, GL_FLOAT, GL_FALSE, 0, 0);
+			glBindBuffer(GL_ARRAY_BUFFER, 0);
+		}
+
+		/*
+			This functions loads a indices buffer and binds it to a vao.
+			(Using this method of rendering is way more effici<63>nt with large/complex meshes.
+			This way you won't have to specify double or more occuring vertices. You just use sort of a lookup table
+			to choose which vertex to get)
+
+			Example:
+				std::vector<float> vertices =
+				{
+				  -0.5f, 0.5f, 0,
+				  -0.5f, -0.5f, 0,
+				  0.5f, -0.5f, 0,
+				  0.5f, 0.5f, 0
+				};
+
+				std::vector<int> indices =
+				{
+					0,1,3,
+					3,1,2
+				};
+		*/
+		static void bindIndicesBuffer(std::vector<unsigned int>& indices)
+		{
+			GLuint vboID;
+			glGenBuffers(1, &vboID);
+			vbos.push_back(vboID);
+			glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vboID);
+			glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(int) * indices.size(), &indices[0], GL_STATIC_DRAW);
+		}
+	}
+}