updated glfw code to fix scaling on macOS

examples/glfw/glfw.go

@@ -5,7 +5,7 @@ import (
 	"runtime"
 
 	"github.com/go-gl/gl/v3.2-core/gl"
-	"github.com/go-gl/glfw/v3.2/glfw"
+	"github.com/go-gl/glfw/v3.3/glfw"
 	"github.com/tfriedel6/canvas"
 	"github.com/tfriedel6/canvas/backend/goglbackend"
 )
@@ -47,8 +47,9 @@ func main() {
 		log.Fatalf("Error loading canvas GL assets: %v", err)
 	}
 
-	window.SetCursorPosCallback(func(w *glfw.Window, xpos float64, ypos float64) {
+	var sx, sy float64 = 1, 1
-		mx, my = xpos, ypos
+	window.SetCursorPosCallback(func(w *glfw.Window, xpos, ypos float64) {
+		mx, my = xpos*sx, ypos*sy
 	})
 
 	// initialize canvas with zero size, since size is set in main loop
@@ -56,14 +57,20 @@ func main() {
 
 	for !window.ShouldClose() {
 		window.MakeContextCurrent()
+
+		// find window size and scaling
+		ww, wh := window.GetSize()
+		fbw, fbh := window.GetFramebufferSize()
+		sx = float64(fbw) / float64(ww)
+		sy = float64(fbh) / float64(wh)
+
 		glfw.PollEvents()
 
 		// set canvas size
-		ww, wh := window.GetSize()
+		backend.SetBounds(0, 0, fbw, fbh)
-		backend.SetBounds(0, 0, ww, wh)
 
 		// call the run function to do all the drawing
-		run(cv, float64(ww), float64(wh))
+		run(cv, float64(fbw), float64(fbh))
 
 		// swap back and front buffer
 		window.SwapBuffers()

glfwcanvas/glfwcanvas.go

@@ -10,7 +10,7 @@ import (
 	"time"
 
 	"github.com/go-gl/gl/v3.2-core/gl"
-	"github.com/go-gl/glfw/v3.2/glfw"
+	"github.com/go-gl/glfw/v3.3/glfw"
 	"github.com/tfriedel6/canvas"
 	"github.com/tfriedel6/canvas/backend/goglbackend"
 )
@@ -67,7 +67,8 @@ func CreateWindow(w, h int, title string) (*Window, *canvas.Canvas, error) {
 	gl.Enable(gl.MULTISAMPLE)
 
 	// load canvas GL backend
-	backend, err := goglbackend.New(0, 0, w, h, nil)
+	fbw, fbh := window.GetFramebufferSize()
+	backend, err := goglbackend.New(0, 0, fbw, fbh, nil)
 	if err != nil {
 		return nil, nil, fmt.Errorf("Error loading GoGL backend: %v", err)
 	}
@@ -79,6 +80,8 @@ func CreateWindow(w, h int, title string) (*Window, *canvas.Canvas, error) {
 	}
 
 	var mx, my int
+	sx := float64(fbw) / float64(w)
+	sy := float64(fbh) / float64(h)
 
 	window.SetMouseButtonCallback(func(w *glfw.Window, button glfw.MouseButton, action glfw.Action, mod glfw.ModifierKey) {
 		if action == glfw.Press && wnd.MouseDown != nil {
@@ -88,7 +91,7 @@ func CreateWindow(w, h int, title string) (*Window, *canvas.Canvas, error) {
 		}
 	})
 	window.SetCursorPosCallback(func(w *glfw.Window, xpos, ypos float64) {
-		mx, my = int(math.Round(xpos)), int(math.Round(ypos))
+		mx, my = int(math.Round(xpos*sx)), int(math.Round(ypos*sy))
 		if wnd.MouseMove != nil {
 			wnd.MouseMove(mx, my)
 		}
@@ -111,10 +114,13 @@ func CreateWindow(w, h int, title string) (*Window, *canvas.Canvas, error) {
 		}
 	})
 	window.SetSizeCallback(func(w *glfw.Window, width, height int) {
+		fbw, fbh := window.GetFramebufferSize()
+		sx = float64(fbw) / float64(width)
+		sy = float64(fbh) / float64(height)
 		if wnd.SizeChange != nil {
 			wnd.SizeChange(width, height)
 		} else {
-			backend.SetBounds(0, 0, width, height)
+			backend.SetBounds(0, 0, fbw, fbh)
 		}
 	})
 	window.SetCloseCallback(func(w *glfw.Window) {
@@ -169,3 +175,9 @@ func (wnd *Window) MainLoop(run func()) {
 func (wnd *Window) Size() (int, int) {
 	return wnd.Window.GetSize()
 }
+
+// FramebufferSize returns the current width and height of
+// the framebuffer
+func (wnd *Window) FramebufferSize() (int, int) {
+	return wnd.Window.GetFramebufferSize()
+}

go.mod

@@ -3,6 +3,7 @@ module github.com/tfriedel6/canvas
 require (
 	github.com/go-gl/gl v0.0.0-20181026044259-55b76b7df9d2
 	github.com/go-gl/glfw v0.0.0-20181014061658-691ee1b84c51
+	github.com/go-gl/glfw/v3.3/glfw v0.0.0-20191125211704-12ad95a8df72
 	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0
 	github.com/veandco/go-sdl2 v0.3.3
 	golang.org/x/exp v0.0.0-20181106170214-d68db9428509

go.sum

@@ -2,6 +2,8 @@ github.com/go-gl/gl v0.0.0-20181026044259-55b76b7df9d2 h1:78Hza2KHn2PX1jdydQnffa
 github.com/go-gl/gl v0.0.0-20181026044259-55b76b7df9d2/go.mod h1:482civXOzJJCPzJ4ZOX/pwvXBWSnzD4OKMdH4ClKGbk=
 github.com/go-gl/glfw v0.0.0-20181014061658-691ee1b84c51 h1:elGSwayRx7uAsfA5PnVKeTHh+AVsUTmas0CkHOw/DSk=
 github.com/go-gl/glfw v0.0.0-20181014061658-691ee1b84c51/go.mod h1:vR7hzQXu2zJy9AVAgeJqvqgH9Q5CA+iKCZ2gyEVpxRU=
+github.com/go-gl/glfw/v3.3/glfw v0.0.0-20191125211704-12ad95a8df72 h1:b+9H1GAsx5RsjvDFLoS5zkNBzIQMuVKUYQDmxU3N5XE=
+github.com/go-gl/glfw/v3.3/glfw v0.0.0-20191125211704-12ad95a8df72/go.mod h1:tQ2UAYgL5IevRw8kRxooKSPJfGvJ9fJQFa0TUsXzTg8=
 github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 h1:DACJavvAHhabrF08vX0COfcOBJRhZ8lUbR+ZWIs0Y5g=
 github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0/go.mod h1:E/TSTwGwJL78qG/PmXZO1EjYhfJinVAhrmmHX6Z8B9k=
 github.com/veandco/go-sdl2 v0.3.3 h1:4/TirgB2MQ7oww3pM3Yfgf1YbChMlAQAmiCPe5koK0I=