From 4400839ae190b60ed6d53d9776721ff58ddabf6e Mon Sep 17 00:00:00 2001
From: Cat Flynn <me@ktyl.dev>
Date: Mon, 31 Jul 2023 00:08:17 +0200
Subject: [PATCH] chore: extract shader compilation functions to file

---
 CMakeLists.txt |  7 ++++++-
 src/gfx.cpp    | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++
 src/gfx.hpp    |  8 +++++++
 src/hello.cpp  | 55 ++----------------------------------------------
 4 files changed, 73 insertions(+), 54 deletions(-)
 create mode 100644 src/gfx.cpp
 create mode 100644 src/gfx.hpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2cc85e0..c0bea94 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -24,7 +24,12 @@ elseif(APPLE)
     message(FATAL_ERROR "macOS is not supported yet.")
 endif()
 
-add_executable(${PROJECT_NAME} src/hello.cpp src/io.cpp src/triangle.cpp)
+add_executable(${PROJECT_NAME}
+    src/hello.cpp
+    src/io.cpp
+    src/triangle.cpp
+    src/gfx.cpp
+)
 
 if(WIN32)
     add_custom_command(TARGET ${PROJECT_NAME} POST_BUILD
diff --git a/src/gfx.cpp b/src/gfx.cpp
new file mode 100644
index 0000000..d1996ca
--- /dev/null
+++ b/src/gfx.cpp
@@ -0,0 +1,57 @@
+#include "gfx.hpp"
+
+#include <iostream>
+
+#include "io.hpp"
+
+GLuint compileShader(const std::string& shaderPath, GLenum shaderType)
+{
+    GLuint shader;
+    GLint success;
+
+    std::string shaderSource = readFile(shaderPath);
+    const char* source = shaderSource.c_str();
+
+    shader = glCreateShader(shaderType);
+    glShaderSource(shader, 1, &source, NULL);
+    glCompileShader(shader);
+
+    glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
+    if (!success)
+    {
+        GLchar infoLog[512];
+        glGetShaderInfoLog(shader, 512, NULL, infoLog);
+        std::cerr << "shader compilation failed" << std::endl
+            << infoLog << std::endl;
+    }
+
+    return shader;
+}
+
+GLuint compileShaderProgram()
+{
+    GLuint vertShader = compileShader("./vert.glsl", GL_VERTEX_SHADER);
+    GLuint fragShader = compileShader("./frag.glsl", GL_FRAGMENT_SHADER);
+
+    GLuint shaderProgram = glCreateProgram();
+    glAttachShader(shaderProgram, vertShader);
+    glAttachShader(shaderProgram, fragShader);
+    glLinkProgram(shaderProgram);
+
+    GLint success;
+    GLchar infoLog[512];
+    glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
+    if (!success)
+    {
+        glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
+        std::cerr << "shader linking failed" << std::endl
+            << infoLog << std::endl;
+    }
+
+    // We no longer need the individual shaders
+    glDeleteShader(vertShader);
+    glDeleteShader(fragShader);
+
+    return shaderProgram;
+}
+
diff --git a/src/gfx.hpp b/src/gfx.hpp
new file mode 100644
index 0000000..3704574
--- /dev/null
+++ b/src/gfx.hpp
@@ -0,0 +1,8 @@
+#pragma once
+
+#include <string>
+
+#include "GL/glew.h"
+
+GLuint compileShaderProgram();
+GLuint compileShader(const std::string& shaderPath, GLenum shaderType);
\ No newline at end of file
diff --git a/src/hello.cpp b/src/hello.cpp
index 82ba3ed..46b039f 100644
--- a/src/hello.cpp
+++ b/src/hello.cpp
@@ -44,33 +44,9 @@
 
 #include <chrono>
 
-#include "io.hpp"
+#include "gfx.hpp"
 #include "triangle.hpp"
 
-GLuint compileShader(const std::string& shaderPath, GLenum shaderType)
-{
-    GLuint shader;
-    GLint success;
-
-    std::string shaderSource = readFile(shaderPath);
-    const char* source = shaderSource.c_str();
-
-    shader = glCreateShader(shaderType);
-    glShaderSource(shader, 1, &source, NULL);
-    glCompileShader(shader);
-
-    glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
-    if (!success)
-    {
-        GLchar infoLog[512];
-        glGetShaderInfoLog(shader, 512, NULL, infoLog);
-        std::cerr << "shader compilation failed" << std::endl
-            << infoLog << std::endl;
-    }
-
-    return shader;
-}
-
 std::chrono::steady_clock::time_point startTime = std::chrono::steady_clock::now();
 float getTime()
 {
@@ -114,33 +90,6 @@ int initGraphics(GLFWwindow** window)
     return 0;
 }
 
-GLuint getShaderProgram()
-{
-    GLuint vertShader = compileShader("./vert.glsl", GL_VERTEX_SHADER);
-    GLuint fragShader = compileShader("./frag.glsl", GL_FRAGMENT_SHADER);
-
-    GLuint shaderProgram = glCreateProgram();
-    glAttachShader(shaderProgram, vertShader);
-    glAttachShader(shaderProgram, fragShader);
-    glLinkProgram(shaderProgram);
-
-    GLint success;
-    GLchar infoLog[512];
-    glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
-    if (!success)
-    {
-        glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
-        std::cerr << "shader linking failed" << std::endl
-            << infoLog << std::endl;
-    }
-
-    // We no longer need the individual shaders
-    glDeleteShader(vertShader);
-    glDeleteShader(fragShader);
-
-    return shaderProgram;
-}
-
 int main()
 {
     // Calculate period of ISS orbit around the Earth
@@ -157,7 +106,7 @@ int main()
     if (initGraphics(&window) != 0)
         return -1;
 
-    Triangle triangle(getShaderProgram());
+    Triangle triangle(compileShaderProgram());
 
     // Main loop
     while (!glfwWindowShouldClose(window))