September Morn Update

Task/OpenGL/Go/opengl.go

@@ -1,87 +1,91 @@
-// triangle displays a smooth shaded triangle with OpenGL.
 package main
 
 import (
-	"log"
-	"runtime"
-	"time"
-
-	gl "github.com/chsc/gogl/gl21"
-	"github.com/mewmew/glfw/win"
+    gl "github.com/chsc/gogl/gl21"
+    "github.com/go-gl/glfw/v3.2/glfw"
+    "log"
+    "runtime"
 )
 
 // Window dimensions.
 const (
-	Width  = 640
-	Height = 480
+    Width  = 640
+    Height = 480
 )
 
+func check(err error) {
+    if err != nil {
+        log.Fatal(err)
+    }
+}
+
 func main() {
-	// OpenGL requires a dedicated OS thread.
-	runtime.LockOSThread()
-	defer runtime.UnlockOSThread()
+    // OpenGL requires a dedicated OS thread.
+    runtime.LockOSThread()
+    defer runtime.UnlockOSThread()
 
-	// Open window with the specified dimensions.
-	err := win.Open(Width, Height)
-	if err != nil {
-		log.Fatalln(err)
-	}
-	defer win.Close()
+    err := glfw.Init()
+    check(err)
+    defer glfw.Terminate()
 
-	// Initiate viewport.
-	resize(Width, Height)
+    // Open window with the specified dimensions.
+    window, err := glfw.CreateWindow(Width, Height, "Triangle", nil, nil)
+    check(err)
 
-	// Register that we are interested in receiving close and resize events.
-	win.EnableCloseChan()
-	win.EnableResizeChan()
+    window.MakeContextCurrent()
 
-	// 60 frames per second.
-	c := time.Tick(time.Second / 60)
+    err = gl.Init()
+    check(err) /* may need to comment out this line for this program to work on Windows 10 */
 
-	// Event loop.
-	for {
-		select {
-		case <-win.CloseChan:
-			return
-		case e := <-win.ResizeChan:
-			resize(e.Width, e.Height)
-		case <-c:
-			draw()
-		}
-	}
+    // Initiate viewport.
+    resize(Width, Height)
+
+    // Register that we are interested in receiving close and resize events.
+    window.SetCloseCallback(func(w *glfw.Window) {
+        return
+    })
+    window.SetSizeCallback(func(w *glfw.Window, width, height int) {
+        resize(width, height)
+    })
+
+    for !window.ShouldClose() {
+        draw()
+        window.SwapBuffers()
+        glfw.PollEvents()
+    }
 }
 
 // resize resizes the window to the specified dimensions.
 func resize(width, height int) {
-	gl.Viewport(0, 0, gl.Sizei(width), gl.Sizei(height))
-	gl.MatrixMode(gl.PROJECTION)
-	gl.LoadIdentity()
-	gl.Ortho(-30.0, 30.0, -30.0, 30.0, -30.0, 30.0)
-	gl.MatrixMode(gl.MODELVIEW)
+    gl.Viewport(0, 0, gl.Sizei(width), gl.Sizei(height))
+    gl.MatrixMode(gl.PROJECTION)
+    gl.LoadIdentity()
+    gl.Ortho(-30.0, 30.0, -30.0, 30.0, -30.0, 30.0)
+    gl.MatrixMode(gl.MODELVIEW)
 }
 
 // draw draws the triangle.
 func draw() {
-	gl.ClearColor(0.3, 0.3, 0.3, 0.0)
-	gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
+    gl.ClearColor(0.3, 0.3, 0.3, 0.0)
+    gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
 
-	gl.ShadeModel(gl.SMOOTH)
+    gl.ShadeModel(gl.SMOOTH)
 
-	gl.LoadIdentity()
-	gl.Translatef(-15.0, -15.0, 0.0)
+    gl.LoadIdentity()
+    gl.Translatef(-15.0, -15.0, 0.0)
 
-	gl.Begin(gl.TRIANGLES)
+    gl.Begin(gl.TRIANGLES)
 
-	gl.Color3f(1.0, 0.0, 0.0)
-	gl.Vertex2f(0.0, 0.0)
+    gl.Color3f(1.0, 0.0, 0.0)
+    gl.Vertex2f(0.0, 0.0)
 
-	gl.Color3f(0.0, 1.0, 0.0)
-	gl.Vertex2f(30.0, 0.0)
+    gl.Color3f(0.0, 1.0, 0.0)
+    gl.Vertex2f(30.0, 0.0)
 
-	gl.Color3f(0.0, 0.0, 1.0)
-	gl.Vertex2f(0.0, 30.0)
+    gl.Color3f(0.0, 0.0, 1.0)
+    gl.Vertex2f(0.0, 30.0)
 
-	gl.End()
+    gl.End()
 
-	win.SwapBuffers()
+    gl.Flush()
 }