mobile/app/darwin.go

143 lines
3.6 KiB
Go

// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build darwin
package app
// Simple on-screen app debugging for OS X. Not an officially supported
// development target for apps, as screens with mice are very different
// than screens with touch panels.
/*
#cgo CFLAGS: -x objective-c
#cgo LDFLAGS: -framework Cocoa -framework OpenGL -framework QuartzCore
#import <Cocoa/Cocoa.h>
#import <OpenGL/gl.h>
#include <pthread.h>
void glGenVertexArrays(GLsizei n, GLuint* array);
void glBindVertexArray(GLuint array);
void runApp(void);
void lockContext(GLintptr);
void unlockContext(GLintptr);
double backingScaleFactor();
uint64 threadID();
*/
import "C"
import (
"log"
"runtime"
"sync"
"code.google.com/p/go.mobile/event"
"code.google.com/p/go.mobile/geom"
"code.google.com/p/go.mobile/gl"
)
var initThreadID uint64
func init() {
// Lock the goroutine responsible for initialization to an OS thread.
// This means the goroutine running main (and calling the run function
// below) is locked to the OS thread that started the program. This is
// necessary for the correct delivery of Cocoa events to the process.
//
// A discussion on this topic:
// https://groups.google.com/forum/#!msg/golang-nuts/IiWZ2hUuLDA/SNKYYZBelsYJ
runtime.LockOSThread()
initThreadID = uint64(C.threadID())
}
func run(callbacks Callbacks) {
if tid := uint64(C.threadID()); tid != initThreadID {
log.Fatalf("app.Run called on thread %d, but app.init ran on %d", tid, initThreadID)
}
cb = callbacks
C.runApp()
}
//export setGeom
func setGeom(pixelsPerPt float32, width, height int) {
// Macs default to 72 DPI, so scales are equivalent.
geom.PixelsPerPt = pixelsPerPt
geom.Width = geom.Pt(float32(width) / pixelsPerPt)
geom.Height = geom.Pt(float32(height) / pixelsPerPt)
}
func initGL() {
// Using attribute arrays in OpenGL 3.3 requires the use of a VBA.
// But VBAs don't exist in ES 2. So we bind a default one.
var id C.GLuint
C.glGenVertexArrays(1, &id)
C.glBindVertexArray(id)
}
var cb Callbacks
var initGLOnce sync.Once
var events struct {
sync.Mutex
pending []event.Touch
}
func sendTouch(ty event.TouchType, x, y float32) {
events.Lock()
events.pending = append(events.pending, event.Touch{
Type: ty,
Loc: geom.Point{
X: geom.Pt(x / geom.PixelsPerPt),
Y: geom.Height - geom.Pt(y/geom.PixelsPerPt),
},
})
events.Unlock()
}
//export eventMouseDown
func eventMouseDown(x, y float32) { sendTouch(event.TouchStart, x, y) }
//export eventMouseDragged
func eventMouseDragged(x, y float32) { sendTouch(event.TouchMove, x, y) }
//export eventMouseEnd
func eventMouseEnd(x, y float32) { sendTouch(event.TouchEnd, x, y) }
//export drawgl
func drawgl(ctx C.GLintptr) {
// The call to lockContext loads the OpenGL context into
// thread-local storage for use by the underlying GL calls
// done in the user's Draw function. We need to stay on
// the same thread throughout Draw, so we LockOSThread.
runtime.LockOSThread()
C.lockContext(ctx)
initGLOnce.Do(initGL)
events.Lock()
pending := events.pending
events.pending = nil
events.Unlock()
for _, e := range pending {
if cb.Touch != nil {
cb.Touch(e)
}
}
// TODO: is the library or the app responsible for clearing the buffers?
gl.ClearColor(0, 0, 0, 1)
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
if cb.Draw != nil {
cb.Draw()
}
C.unlockContext(ctx)
// This may unlock the original main thread, but that's OK,
// because by the time it does the thread has already entered
// C.runApp, which won't give the thread up.
runtime.UnlockOSThread()
}