ui: Adjust window size in case when glfwGetVideoMode fails (#328)

internal/ui/ui_glfw.go

@@ -194,6 +194,7 @@ func Run(width, height int, scale float64, title string, g GraphicsContext) erro
 		w, h := u.glfwSize()
 		x := (v.Width - w) / 2
 		y := (v.Height - h) / 3
+		x, y = adjustWindowPosition(x, y)
 		u.window.SetPos(x, y)
 		return nil
 	}); err != nil {

internal/ui/ui_linux.go

@@ -25,3 +25,7 @@ func deviceScale() float64 {
 func glfwScale() float64 {
 	return deviceScale()
 }
+
+func adjustWindowPosition(x, y int) (int, int) {
+	return x, y
+}

internal/ui/ui_mac.go

@@ -36,3 +36,7 @@ func deviceScale() float64 {
 func glfwScale() float64 {
 	return 1
 }
+
+func adjustWindowPosition(x, y int) (int, int) {
+	return x, y
+}

internal/ui/ui_windows.go

@@ -30,6 +30,11 @@ package ui
 //   }
 //   return "";
 // }
+//
+// static int getCaptionHeight() {
+//   return GetSystemMetrics(SM_CYCAPTION);
+// }
+//
 import "C"
 
 func deviceScale() float64 {
@@ -43,3 +48,16 @@ func deviceScale() float64 {
 func glfwScale() float64 {
 	return deviceScale()
 }
+
+func adjustWindowPosition(x, y int) (int, int) {
+	// As the video width/height might be wrong,
+	// adjust x/y at least to enable to handle the window (#328)
+	if x < 0 {
+		x = 0
+	}
+	t := int(C.getCaptionHeight())
+	if y < t {
+		y = t
+	}
+	return x, y
+}