Shader exercises complete!

Makefile

@@ -3,7 +3,7 @@ CFLAGS = -std=c++17 -O2
 LDFLAGS = -lglfw3 -lGL -ldl -lpthread -lX11 -lXxf86vm -lXrandr -lXi
 OUT_NAME = LearnOpenGL
 
-build: src/main.cpp 
+build: src/main.cpp  src/shader.h
 	mkdir -p build/
 	$(CC) $(CFLAGS) -Ilib/GLAD/include -Ilib/glfw/include -o build/$(OUT_NAME) lib/GLAD/src/glad.c src/main.cpp $(LDFLAGS)
 

shader.fs

@@ -0,0 +1,11 @@
+#version 460 core
+out vec4 FragColor;
+
+in vec4 ourPosition;
+
+in vec3 ourColor;
+    
+void main()
+{
+    FragColor = ourPosition;// vec4(ourColor, 1.0f);
+}

shader.vs

@@ -0,0 +1,15 @@
+#version 460 core
+layout (location=0) in vec3 aPos;
+layout (location=1) in vec3 aColor;
+
+uniform float HorizontalOffset;
+
+out vec3 ourColor;
+out vec4 ourPosition;
+
+void main(){
+
+    gl_Position = vec4(-aPos.x + HorizontalOffset, aPos.yz , 1.0);
+    ourColor = aColor;
+    ourPosition = gl_Position;
+}

src/main.cpp

@@ -1,8 +1,11 @@
 #include <stdio.h>
+#include <cmath>
 
 #include <glad/glad.h>
 #include <GLFW/glfw3.h>
 
+#include "shader.h"
+
 
 void framebuffer_size_callback(GLFWwindow* window, int width, int height) {
    glViewport(0,0, width, height);
@@ -41,82 +44,20 @@ int main() {
 
    glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
 
-   // TODO: Load from disk 
+   Shader shader("shader.vs", "shader.fs");
-   const char* vertextShaderSource = 
-      "#version 460 core\n"
-      "layout (location=0) in vec3 aPos;\n"
-      "void main(){\n"
-      "gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
-      "}\n";
-
-   unsigned int vertexShader;
-   vertexShader = glCreateShader(GL_VERTEX_SHADER);
-   glShaderSource(vertexShader, 1, &vertextShaderSource, NULL);
-   glCompileShader(vertexShader);
-
-   int success;
-   char infolog[512];
-   glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
-
-   if(!success){
-      glGetShaderInfoLog(vertexShader, 512, NULL, infolog);
-      printf ( "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n %s", infolog);
-
-   }
-
-
-   //TODO: load from disk
-   const char* fragmentShaderSource = 
-      "#version 330 core\n"
-      "out vec4 FragColor;\n"
-      "void main(){\n"
-      "FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
-      "}\n";
-
-   unsigned int fragmentShader;
-   fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
-   glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
-   glCompileShader(fragmentShader);
-
-   glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
-
-   if(!success){
-      glGetShaderInfoLog(fragmentShader, 512 ,NULL,infolog);
-      printf("ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n %s", infolog);
-   }
-
-
-
-   unsigned int shaderProgram;
-   shaderProgram = glCreateProgram();
-
-   glAttachShader(shaderProgram, vertexShader);
-   glAttachShader(shaderProgram, fragmentShader);
-   glLinkProgram(shaderProgram);
-
-   glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
-   if(!success) {
-      glGetProgramInfoLog(shaderProgram, 512, NULL, infolog);
-      printf("ERROR::SHADER_PROGRAM::LINKING_FAILED\n %s", infolog);
-   }
-
-
-   glDeleteShader(vertexShader);
-   glDeleteShader(fragmentShader);
 
 
 
 
    float vertices[] = {
-      0.5f, 0.5f, 0.0f, // top, right
+      0.5f, -0.5f, 0.0f,   1.0f, 0.0f, 0.0f, // bottom right
-      0.5f, -0.5f, 0.0f, // bottom right
+      -0.5f, -0.5f, 0.0f,  0.0f, 1.0f, 0.0f, // bottom left
-      -0.5f, -0.5f, 0.0f, // bottom left
+      0.0f, 0.5f, 0.0f,    0.0f, 0.0f, 1.0f  // top
-      -0.5f, 0.5f, 0.0f // top left
+
    };
 
    unsigned int indices[] = {
-         0, 1,3, // first triangle
+         0, 1,2 // first triangle
-         1,2,3 // second triangle
    };
 
    // Vertex buffer objects!!
@@ -133,9 +74,12 @@ int main() {
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
 
-
+   // Position attribute
-   glVertexAttribPointer(0,3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
+   glVertexAttribPointer(0,3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);
+   // Color attribute
+   glVertexAttribPointer(1,3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)(3* sizeof(float)));
+   glEnableVertexAttribArray(1);
 
    glBindBuffer(GL_ARRAY_BUFFER, 0);
 
@@ -150,11 +94,15 @@ int main() {
 
       glClear(GL_COLOR_BUFFER_BIT);
 
-      glUseProgram(shaderProgram);
+
+      shader.use();
+      shader.setFloat("HorizontalOffset", .3);
+
       glBindVertexArray(VAO);
       glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
+      
       glDrawElements(GL_TRIANGLES, 6,GL_UNSIGNED_INT,  0);
-      glBindVertexArray(0);
+      
 
       glfwSwapBuffers(window);
       glfwPollEvents();
@@ -162,7 +110,6 @@ int main() {
 
    glDeleteVertexArrays(1, &VAO);
    glDeleteBuffers(1, &VBO);
-   glDeleteProgram(shaderProgram);
 
    glfwTerminate();
 

src/shader.h

@@ -0,0 +1,133 @@
+#pragma once
+#include <glad/glad.h>
+
+#include <string>
+#include <fstream>
+#include <sstream>
+#include <iostream>
+
+class Shader
+{
+    public:
+        unsigned int ID;// Program ID
+
+        // Read and build the shader upon construction
+        Shader(const char* vertexPath, const char* fragmentPath);
+
+        // Activate the shader
+        void use();
+
+        void setBool(const std::string &name, bool value)const;
+        void setInt(const std::string &name, int value)const;
+        void setFloat(const std::string &name, float value)const;
+
+
+};
+
+
+Shader::Shader(const char* vertextPath, const char* fragmentPath)
+{
+    // retrieve the vertex / fragment source code from filepath
+    std::string vertexCode;
+    std::string fragmentCode;
+    std::ifstream vShaderFile;
+    std::ifstream fShaderFile;
+
+    vShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);
+    fShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);
+
+    try{
+        vShaderFile.open(vertextPath);
+        fShaderFile.open(fragmentPath);
+
+        std::stringstream vShaderStream,fShaderStream;
+
+        vShaderStream << vShaderFile.rdbuf();
+        fShaderStream << fShaderFile.rdbuf();
+
+        vShaderFile.close();
+        fShaderFile.close();
+
+        vertexCode = vShaderStream.str();
+
+        std::cout << "VertexShaderSource:\n\n" << vertexCode << std::endl;
+
+        fragmentCode = fShaderStream.str();
+
+        std::cout << "FragmentShaderSource:\n\n" << fragmentCode << std::endl;
+
+    }
+    catch(std::ifstream::failure e){
+        std::cout << "ERROR::SHADER::FILE_NOT_SUCCESFULLY_READ" << std::endl << e.what() << std::endl ;
+    }
+
+    const char* vShaderCode = vertexCode.c_str();
+    const char* fShaderCode = fragmentCode.c_str();
+
+
+    // Compile Shaders
+    unsigned int vertex, fragment;
+    int success;
+    char infoLog[512];
+
+    // vertex shader
+    vertex = glCreateShader(GL_VERTEX_SHADER);
+    glShaderSource(vertex, 1, &vShaderCode, NULL);
+    glCompileShader(vertex);
+
+    // print any compile errors if there are any
+    glGetShaderiv(vertex,GL_COMPILE_STATUS, &success);
+    if(!success)
+    {
+        glGetShaderInfoLog(vertex, 512, NULL, infoLog);
+        std::cout << "ERROR::SHADER:::VERTEX::COMPILATION_FAILED" << std::endl << infoLog << std::endl;
+    }
+
+    // fragment shader
+
+    fragment = glCreateShader(GL_FRAGMENT_SHADER);
+    glShaderSource(fragment, 1, &fShaderCode, NULL);
+    glCompileShader(fragment);
+
+    glGetShaderiv(fragment, GL_COMPILE_STATUS, &success);
+    if(!success){
+        glGetShaderInfoLog(fragment, 512, NULL, infoLog);
+        std::cout << "ERROR::SHADER:::VERTEX::COMPILATION_FAILED" << std::endl << infoLog << std::endl;
+    }
+
+
+    // Shader Program
+    ID = glCreateProgram();
+    glAttachShader(ID, vertex);
+    glAttachShader(ID, fragment);
+    glLinkProgram(ID);
+
+    glGetProgramiv(ID, GL_LINK_STATUS, &success);
+    if(!success){
+        glGetProgramInfoLog(ID, 512, NULL, infoLog);
+        std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED" << std::endl << infoLog << std::endl;
+    }
+
+    // delete shaders as they're now linked into our program and no longer necessary
+    glDeleteShader(vertex);
+    glDeleteShader(fragment);
+
+
+}
+
+
+void Shader::use(){
+    glUseProgram(ID);
+}
+
+void Shader::setBool(const std::string &name, bool value) const{
+    glUniform1i(glGetUniformLocation(ID, name.c_str()), (int) value );
+}
+
+void Shader::setInt(const std::string &name, int value) const{
+    glUniform1i(glGetUniformLocation(ID, name.c_str()),  value );
+}
+
+void Shader::setFloat(const std::string &name, float value) const{
+    glUniform1f(glGetUniformLocation(ID, name.c_str()),  value );
+}

src/vertex.shader

@@ -1,7 +0,0 @@
-#version 460 core
-layout (location=0) in vec3 aPos;
-
-void main(){
-    gl_Position = vec4(aPos.x, aPos.y, aPos.z 1.0);
-
-}