package al /* #include #include #include "helpers.h" #include "callbacks.h" */ import "C" import "unsafe" // Callback function for CreateCustomBitmap() type CreateCustomBitmapCallback func(bitmap *Bitmap, data interface{}) bool // Callback context for CreateCustomBitmap() type createCustomBitmapContext struct { fn CreateCustomBitmapCallback data interface{} } //export go_create_custom_bitmap_callback func go_create_custom_bitmap_callback(ptr unsafe.Pointer, context unsafe.Pointer) C.bool { ccbd := (*createCustomBitmapContext)(context) cbmp := (*C.ALLEGRO_BITMAP)(ptr) bmp := wrapBitmapRaw(cbmp) fptr := ccbd.fn return b2cb((fptr)(bmp, ccbd.data)) } // generic function pointer caller var CallbackInt func() int = nil //export go_generic_callback_int func go_generic_callback_int() int { if CallbackInt != nil { return CallbackInt() } return 0 } type CallbackFunction func() int type callbackData struct { fn CallbackFunction data unsafe.Pointer } // the function below is the C callback that will be given to the // C api that needs a callback. It uses a callback context with a // Go function pointer in it to call that go function. //export go_take_callback_callback func go_take_callback_callback(context unsafe.Pointer) int { cbd := (*callbackData)(context) fn := cbd.fn return fn() } // Finally wrap the C callback caller function. func TakeCallback(fn CallbackFunction) int { ctx := unsafe.Pointer(&callbackData{fn, nil}) return int(C.go_take_callback(ctx)) }