From 9817d78cd0808d2776b89f6ce5cfd019ccce13c3 Mon Sep 17 00:00:00 2001
From: hodasemi <michaelh.95@t-online.de>
Date: Sat, 20 Jul 2019 08:58:27 +0200
Subject: [PATCH] Add Rust OpenGL example

---
 .gitignore              |  5 +++-
 .vscode/tasks.json      | 19 +++++++++++++
 ecg-example/Cargo.toml  | 11 ++++++++
 ecg-example/src/main.rs | 62 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 96 insertions(+), 1 deletion(-)
 create mode 100644 ecg-example/Cargo.toml
 create mode 100644 ecg-example/src/main.rs

diff --git a/.gitignore b/.gitignore
index 10891cc..20478a6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,4 +3,7 @@ exercise2/build/
 exercise3/build/
 exercise4/build/
 
-.vscode/ipch
\ No newline at end of file
+.vscode/ipch
+
+Cargo.lock
+target/
\ No newline at end of file
diff --git a/.vscode/tasks.json b/.vscode/tasks.json
index 8f14c13..b55a66d 100644
--- a/.vscode/tasks.json
+++ b/.vscode/tasks.json
@@ -99,5 +99,24 @@
         "clear": true
       }
     },
+    {
+      "type": "shell",
+      "label": "Run Example",
+      "command": "cd ecg-example && cargo run",
+      "args": [],
+      "problemMatcher": [
+        "$rustc"
+      ],
+      "presentation": {
+        "clear": true
+      },
+      "linux": {
+        "options": {
+          "env": {
+            "RUST_BACKTRACE": "1",
+          }
+        }
+      }
+    },
   ]
 }
\ No newline at end of file
diff --git a/ecg-example/Cargo.toml b/ecg-example/Cargo.toml
new file mode 100644
index 0000000..5ce3629
--- /dev/null
+++ b/ecg-example/Cargo.toml
@@ -0,0 +1,11 @@
+[package]
+name = "ecg-example"
+version = "0.1.0"
+authors = ["hodasemi <michaelh.95@t-online.de>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+sdl2 = "*"
+gl = "*"
diff --git a/ecg-example/src/main.rs b/ecg-example/src/main.rs
new file mode 100644
index 0000000..9d00367
--- /dev/null
+++ b/ecg-example/src/main.rs
@@ -0,0 +1,62 @@
+use gl::load_with;
+
+use sdl2;
+use sdl2::{event::Event, video::GLProfile};
+
+fn main() -> Result<(), String> {
+    // init sdl2
+    let sdl_context = sdl2::init()?;
+
+    // init video_subsystem
+    let video_subsystem = sdl_context.video()?;
+
+    // gl context configuration
+    let gl_attr = video_subsystem.gl_attr();
+    gl_attr.set_context_profile(GLProfile::Core);
+    gl_attr.set_context_version(3, 3);
+
+    // create window
+    let window = video_subsystem
+        .window("ECG Example", 1280, 720)
+        .position_centered()
+        .opengl()
+        .build()
+        .map_err(|e| e.to_string())?;
+
+    // create opengl context handle
+    let opengl_context = window.gl_create_context()?;
+
+    // load opengl functions from system library
+    load_with(|s| video_subsystem.gl_get_proc_address(s) as *const _);
+
+    // enable vsync
+    video_subsystem.gl_set_swap_interval(1);
+
+    // init sdl2 event system
+    let mut event_pump = sdl_context.event_pump()?;
+
+    // main loop
+    'running: loop {
+        // check for events
+        for event in event_pump.poll_iter() {
+            match event {
+                Event::Quit { .. } => break 'running,
+                _ => {}
+            }
+        }
+
+        // activate opengl context
+        window.gl_make_current(&opengl_context)?;
+
+        // OpenGL stuff ...
+        unsafe {
+            gl::ClearColor(1.0, 0.0, 0.0, 1.0);
+            gl::Clear(gl::COLOR_BUFFER_BIT);
+        }
+
+        // swap back buffer
+        window.gl_swap_window();
+    }
+
+    Ok(())
+}