updated gogl backend to work on ios as well, updated ios example

backend/gogl/gl/package.go

@@ -16,7 +16,7 @@
 //
 package gl
 
-// #cgo darwin           LDFLAGS: -framework OpenGL
+// #cgo darwin           LDFLAGS: -framework OpenGLES
 // #cgo linux,!android   LDFLAGS: -lGL
 // #cgo freebsd,!android LDFLAGS: -lGL
 // #cgo windows          LDFLAGS: -lopengl32
@@ -49,7 +49,7 @@ package gl
 // typedef float GLfloat;
 // typedef double GLdouble;
 // typedef char GLchar;
-// #include <KHR/khrplatform.h>
+// #include "khrplatform.h"
 // typedef unsigned int GLenum;
 // typedef unsigned char GLboolean;
 // typedef unsigned int GLbitfield;

backend/gogl/gl/procaddr.go

@@ -1,4 +1,4 @@
-// +build !android
+// +build !android,!ios
 // Code generated by glow (https://github.com/go-gl/glow). DO NOT EDIT.
 
 // This file implements GlowGetProcAddress for every supported platform. The

backend/gogl/gl/procaddr_mobile.go

@@ -1,3 +1,5 @@
+// +build android ios
+
 // Code generated by glow (https://github.com/go-gl/glow). DO NOT EDIT.
 
 // This file implements GlowGetProcAddress for every supported platform. The
@@ -17,7 +19,14 @@ package gl
 
 /*
 #cgo android LDFLAGS: -lGLESv2
+#cgo android CFLAGS: -DANDROID
+#cgo ios     CFLAGS: -DIOS
+#ifdef ANDROID
  #include <GLES2/gl2.h>
+#endif
+#ifdef IOS
+ #include <OpenGLES/ES2/GL.h>
+#endif
 */
 import "C"
 import "unsafe"

examples/ios/README.md

@@ -1,5 +1,7 @@
+As of this writing, gomobile does not support go modules. In this case this project can only be compiled while it is in the GOPATH/src directory.
+
 Run this command:
 
-gomobile bind -target ios
+gomobile bind -target ios -tags ios
 
 Then add the resulting Example.framework into the Xcode project, and it should compile and run from there

examples/ios/ios.go

@@ -2,10 +2,9 @@ package example
 
 import (
 	"math"
-	"time"
 
 	"github.com/tfriedel6/canvas"
-	"github.com/tfriedel6/canvas/glimpl/ios"
+	"github.com/tfriedel6/canvas/backend/gogl"
 )
 
 var cv *canvas.Canvas
@@ -16,12 +15,11 @@ func TouchEvent(typ string, x, y int) {
 }
 
 func LoadGL(w, h int) {
-	err := canvas.LoadGL(glimplios.GLImpl{})
+	backend, err := goglbackend.New(0, 0, w, h)
 	if err != nil {
-		time.Sleep(100 * time.Millisecond)
 		panic(err)
 	}
-	cv = canvas.New(0, 0, w, h)
+	cv = canvas.New(backend)
 }
 
 func DrawFrame() {