From b0a3bc3f3dbc405aff6329fb0e19ac9da7c97234 Mon Sep 17 00:00:00 2001
From: Clemens Albrecht <clemens.albrecht@posteo.de>
Date: Fri, 11 Apr 2025 10:43:28 +0200
Subject: [PATCH] move shaders to files

---
 README.md      |  4 ++++
 data/main.frag |  6 ++++++
 data/main.vert |  8 ++++++++
 src/main.rs    | 39 ++++++++++++++++-----------------------
 4 files changed, 34 insertions(+), 23 deletions(-)
 create mode 100644 README.md
 create mode 100644 data/main.frag
 create mode 100644 data/main.vert

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..7be96b6
--- /dev/null
+++ b/README.md
@@ -0,0 +1,4 @@
+# Opengl-Starter
+
+This is a template for developing an OpenGL based application in Rust.
+It targets OpenGL Core 4.6 on Linux.
diff --git a/data/main.frag b/data/main.frag
new file mode 100644
index 0000000..43d4866
--- /dev/null
+++ b/data/main.frag
@@ -0,0 +1,6 @@
+#version 460 core
+in vec3 ourColor;
+out vec4 FragColor;
+void main() {
+    FragColor = vec4(ourColor, 1.0);
+}
diff --git a/data/main.vert b/data/main.vert
new file mode 100644
index 0000000..84b0200
--- /dev/null
+++ b/data/main.vert
@@ -0,0 +1,8 @@
+#version 460 core
+layout(location = 0) in vec3 aPos;
+layout(location = 1) in vec3 aColor;
+out vec3 ourColor;
+void main() {
+    gl_Position = vec4(aPos, 1.0);
+    ourColor = aColor;
+}
diff --git a/src/main.rs b/src/main.rs
index 9f5cbaf..f9a93c3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -7,14 +7,14 @@
 use glow::{Context, HasContext, NativeProgram, NativeVertexArray};
 use glutin::{
     config::{ConfigSurfaceTypes, ConfigTemplateBuilder},
-    context::{ContextAttributesBuilder, GlProfile, PossiblyCurrentContext},
+    context::{ContextApi, ContextAttributesBuilder, GlProfile, PossiblyCurrentContext, Version},
     display::GetGlDisplay,
     prelude::*,
     surface::{Surface, SurfaceAttributesBuilder, WindowSurface},
 };
 use glutin_winit::DisplayBuilder;
 use raw_window_handle::HasRawWindowHandle;
-use std::{error::Error, ffi::CString};
+use std::{error::Error, ffi::CString, fs::File, io::Read, path::Path};
 use winit::{
     application::ApplicationHandler,
     event::WindowEvent,
@@ -97,6 +97,16 @@ impl ApplicationHandler for App {
 }
 
 fn main() -> Result<(), Box<dyn Error>> {
+    let mut vert_shader_file =
+        File::open(Path::new("./data/main.vert")).expect("Didn't find vertex shader");
+    let mut vert_shader_src = "".to_string();
+    vert_shader_file.read_to_string(&mut vert_shader_src)?;
+
+    let mut frag_shader_file =
+        File::open(Path::new("./data/main.frag")).expect("Didn't find fragment shader");
+    let mut frag_shader_src = "".to_string();
+    frag_shader_file.read_to_string(&mut frag_shader_src)?;
+
     // Create an event loop
     let event_loop = EventLoop::new().unwrap();
     event_loop.set_control_flow(ControlFlow::Poll);
@@ -133,8 +143,9 @@ fn main() -> Result<(), Box<dyn Error>> {
 
     // Create OpenGL context attributes
     let context_attributes = ContextAttributesBuilder::new()
+        .with_context_api(ContextApi::OpenGl(Some(Version::new(4, 6))))
         .with_profile(GlProfile::Core)
-        .build(None);
+        .build(window.raw_window_handle().ok());
 
     // Create the OpenGL surface attributes
     let surface_attributes = SurfaceAttributesBuilder::<WindowSurface>::new().build(
@@ -177,17 +188,7 @@ fn main() -> Result<(), Box<dyn Error>> {
         let vertex_shader = gl
             .create_shader(glow::VERTEX_SHADER)
             .expect("Cannot create shader");
-        let vertex_shader_src = r#"
-            #version 330 core
-            layout (location = 0) in vec3 aPos;
-            layout (location = 1) in vec3 aColor;
-            out vec3 ourColor;
-            void main() {
-                gl_Position = vec4(aPos, 1.0);
-                ourColor = aColor;
-            }
-        "#;
-        gl.shader_source(vertex_shader, vertex_shader_src);
+        gl.shader_source(vertex_shader, &vert_shader_src);
         gl.compile_shader(vertex_shader);
 
         // Check for shader compilation errors
@@ -200,15 +201,7 @@ fn main() -> Result<(), Box<dyn Error>> {
         let fragment_shader = gl
             .create_shader(glow::FRAGMENT_SHADER)
             .expect("Cannot create shader");
-        let fragment_shader_src = r#"
-            #version 330 core
-            in vec3 ourColor;
-            out vec4 FragColor;
-            void main() {
-                FragColor = vec4(ourColor, 1.0);
-            }
-        "#;
-        gl.shader_source(fragment_shader, fragment_shader_src);
+        gl.shader_source(fragment_shader, &frag_shader_src);
         gl.compile_shader(fragment_shader);
 
         // Check for shader compilation errors