From 1f217971fd072b7a5bf7ba6e1841cc369fb9eda5 Mon Sep 17 00:00:00 2001
From: Cat Flynn <me@ktyl.dev>
Date: Sun, 6 Aug 2023 13:08:49 +0200
Subject: [PATCH] feat: unlit shader program

---
 CMakeLists.txt             |  6 ++++--
 frag.glsl => frag_lit.glsl |  0
 frag_unlit.glsl            |  9 +++++++++
 src/gfx.cpp                |  4 ++--
 src/gfx.hpp                |  2 +-
 src/hello.cpp              | 18 +++++++++++-------
 6 files changed, 27 insertions(+), 12 deletions(-)
 rename frag.glsl => frag_lit.glsl (100%)
 create mode 100644 frag_unlit.glsl

diff --git a/CMakeLists.txt b/CMakeLists.txt
index fb84799..83ac3d5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -52,8 +52,10 @@ endif()
 
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/vert.glsl
                ${CMAKE_CURRENT_BINARY_DIR}/vert.glsl COPYONLY)
-configure_file(${CMAKE_CURRENT_SOURCE_DIR}/frag.glsl
-               ${CMAKE_CURRENT_BINARY_DIR}/frag.glsl COPYONLY)
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/frag_lit.glsl
+               ${CMAKE_CURRENT_BINARY_DIR}/frag_lit.glsl COPYONLY)
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/frag_unlit.glsl
+               ${CMAKE_CURRENT_BINARY_DIR}/frag_unlit.glsl COPYONLY)
 
 # Append Git version to built executable after it has been built
 find_package(Git)
diff --git a/frag.glsl b/frag_lit.glsl
similarity index 100%
rename from frag.glsl
rename to frag_lit.glsl
diff --git a/frag_unlit.glsl b/frag_unlit.glsl
new file mode 100644
index 0000000..22a3394
--- /dev/null
+++ b/frag_unlit.glsl
@@ -0,0 +1,9 @@
+#version 330 core
+
+out vec4 FragColor;
+
+void main()
+{
+    vec3 objectColor = vec3(1.0, 1.0, 1.0);
+    FragColor = vec4(objectColor, 1.0);
+}
diff --git a/src/gfx.cpp b/src/gfx.cpp
index 700db36..b3c1354 100644
--- a/src/gfx.cpp
+++ b/src/gfx.cpp
@@ -28,10 +28,10 @@ GLuint compileShader(const std::string& shaderPath, GLenum shaderType)
     return shader;
 }
 
-GLuint compileShaderProgram()
+GLuint compileShaderProgram(const std::string& fragShaderPath)
 {
     GLuint vertShader = compileShader("./vert.glsl", GL_VERTEX_SHADER);
-    GLuint fragShader = compileShader("./frag.glsl", GL_FRAGMENT_SHADER);
+    GLuint fragShader = compileShader(fragShaderPath, GL_FRAGMENT_SHADER);
 
     GLuint shaderProgram = glCreateProgram();
     glAttachShader(shaderProgram, vertShader);
diff --git a/src/gfx.hpp b/src/gfx.hpp
index 3704574..88340df 100644
--- a/src/gfx.hpp
+++ b/src/gfx.hpp
@@ -4,5 +4,5 @@
 
 #include "GL/glew.h"
 
-GLuint compileShaderProgram();
+GLuint compileShaderProgram(const std::string& fragShaderPath);
 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 26f75bd..9ea7e48 100644
--- a/src/hello.cpp
+++ b/src/hello.cpp
@@ -149,7 +149,9 @@ int main()
     if (initGraphics(&window) != 0)
         return -1;
 
-    GLuint shaderProgram = compileShaderProgram();
+    GLuint litProgram = compileShaderProgram("./frag_lit.glsl");
+    GLuint unlitProgram = compileShaderProgram("./frag_unlit.glsl");
+
     Icosphere sphere(0.5, 2);
     Orbit orbit(30, glm::vec3(.5, .5, 0));
 
@@ -161,14 +163,16 @@ int main()
         glClearColor(0.2, 0.3, 0.3, 1.0);
         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
-        // Render everything with the same shaders
-        glUseProgram(shaderProgram);
+        float time = glfwGetTime();
 
-        // Update uniforms
-        updateModelViewProjectionMatrix(shaderProgram, glfwGetTime());
-
-        // Render objects
+        // Render lit objects
+        glUseProgram(litProgram);
+        updateModelViewProjectionMatrix(litProgram, time);
         sphere.render();
+
+        // Render unlit objects
+        glUseProgram(unlitProgram);
+        updateModelViewProjectionMatrix(unlitProgram, time);
         orbit.render();
 
         glfwSwapBuffers(window);