changed structs to type alias, addded documentation to high level fun…

…ctions (#5 #4)

mbgl/README.md

@@ -23,4 +23,6 @@ This directory contains direct go bindings against the Mapbox GL Native C++ API.
 * in the higher level package, `runtime.SetFinalizer` is used for memory management, note that this cannot be done for classes (which are aliased as empty structs) as: 
 
 > It is not guaranteed that a finalizer will run if the size of *obj is zero bytes.
-> https://golang.org/pkg/runtime/#SetFinalizer
+> https://golang.org/pkg/runtime/#SetFinalizer
+
+* after calling `(T).Destruct()` make sure to not reuse the variable, this will result in strange errors; another `(T).Destruct()` call might yeild something like "freed block must be allocated with malloc".

mbgl/camera_options.go

@@ -6,8 +6,10 @@ import "C"
  */
 import "C"
 
-type EdgeInsets struct {
-	ptr *C.MbglEdgeInsets
+type EdgeInsets C.MbglEdgeInsets
+
+func (ei *EdgeInsets) edgeInsets() *C.MbglEdgeInsets {
+	return (*C.MbglEdgeInsets)(ei)
 }
 
 func NewEdgeInsets(top, left, bottom, right float64) *EdgeInsets {
@@ -18,11 +20,11 @@ func NewEdgeInsets(top, left, bottom, right float64) *EdgeInsets {
 		C.double(right),
 	)
 
-	return &EdgeInsets{ptr:ptr}
+	return (*EdgeInsets)(ptr)
 }
 
 func (ei *EdgeInsets) Destruct() {
-	C.mbgl_edge_insets_destruct(ei.ptr)
+	C.mbgl_edge_insets_destruct(ei.edgeInsets())
 }
 
 type Point struct {
@@ -69,12 +71,12 @@ func (opt *CameraOptions) update() {
 	// todo (@ear7h): change structs to wrapped types
 	var center *C.MbglLatLng
 	if opt.Center != nil {
-		center = opt.Center.ptr
+		center = opt.Center.latLng()
 	}
 
 	var padding *C.MbglEdgeInsets
 	if opt.Padding != nil {
-		padding = opt.Padding.ptr
+		padding = opt.Padding.edgeInsets()
 	}
 
 	if opt.ptr == nil {

mbgl/default_file_source.go

@@ -6,25 +6,25 @@ package mbgl
  */
 import "C"
 
-type DefaultFileSource struct {
-	ptr *C.MbglDefaultFileSource
+type DefaultFileSource C.MbglDefaultFileSource
+
+func (fs *DefaultFileSource) defaultFileSource() *C.MbglDefaultFileSource {
+	return (*C.MbglDefaultFileSource)(fs)
 }
 
+// This instantiates a new file source which can handle online and offline sources. It will create a chache file
 func NewDefaultFileSource(cachePath, assetRoot string, maxCache *uint64) *DefaultFileSource {
 	ptr :=  C.mbgl_default_file_source_new(C.CString(cachePath),
 		C.CString(assetRoot),
 		(*C.uint64_t)(maxCache))
 
-	return &DefaultFileSource{
-		ptr: ptr,
-	}
+	return (*DefaultFileSource)(ptr)
 }
 
-func (fs DefaultFileSource) fileSource() *C.MbglFileSource {
-	return (*C.MbglFileSource)(fs.ptr)
+func (fs *DefaultFileSource) fileSource() *C.MbglFileSource {
+	return (*C.MbglFileSource)(fs.defaultFileSource())
 }
 
 func (fs *DefaultFileSource) Destruct() {
-	C.mbgl_default_file_source_destruct(fs.ptr)
-	fs.ptr = nil
+	C.mbgl_default_file_source_destruct(fs.defaultFileSource())
 }

mbgl/lat_lng.go

@@ -7,31 +7,29 @@ import "C"
 import "github.com/go-spatial/geom/slippy"
 
 //TODO (@ear7h): use github.com/go-spatial/geom type
-type LatLng struct {
-	ptr *C.MbglLatLng
-}
+type LatLng C.MbglLatLng
 
 func NewLatLng(lat, lng float64) *LatLng {
 	ptr := C.mbgl_lat_lng_new(C.double(lat), C.double(lng))
 
-	return &LatLng{ptr:ptr}
+	return (*LatLng)(ptr)
+}
+
+func (ll *LatLng) latLng() *C.MbglLatLng {
+	return (*C.MbglLatLng)(ll)
 }
 
 func (ll *LatLng) Destruct() {
-	C.mbgl_lat_lng_destruct(ll.ptr)
-	ll.ptr = nil
+	C.mbgl_lat_lng_destruct(ll.latLng())
 }
 
 
 // bounds
-
-type LatLngBounds struct {
-	ptr *C.MbglLatLngBounds
-}
+type LatLngBounds C.MbglLatLngBounds
 
 func NewLatLngBounds(a, b *LatLng) *LatLngBounds {
-	ptr := C.mbgl_lat_lng_bounds_hull(a.ptr, b.ptr)
-	return &LatLngBounds{ptr:ptr}
+	ptr := C.mbgl_lat_lng_bounds_hull(a.latLng(), b.latLng())
+	return (*LatLngBounds)(ptr)
 }
 
 func NewLatLngBoundsFromTile(tile *slippy.Tile) *LatLngBounds {
@@ -48,6 +46,10 @@ func NewLatLngBoundsFromTile(tile *slippy.Tile) *LatLngBounds {
 	return ret
 }
 
+func (bb *LatLngBounds) latLngBounds() *C.MbglLatLngBounds {
+	return (*C.MbglLatLngBounds)(bb)
+}
+
 func (bb *LatLngBounds) Destruct() {
-	C.mbgl_lat_lng_bounds_destruct(bb.ptr)
+	C.mbgl_lat_lng_bounds_destruct(bb.latLngBounds())
 }

mbgl/map_snapshotter.go

@@ -12,9 +12,7 @@ import (
 	"fmt"
 )
 
-type MapSnapshotter struct {
-	ptr *C.MbglMapSnapshotter
-}
+type MapSnapshotter C.MbglMapSnapshotter
 
 
 func NewMapSnapshotter(src FileSource,
@@ -38,7 +36,7 @@ func NewMapSnapshotter(src FileSource,
 
 		var _region *C.MbglLatLngBounds
 		if region != nil {
-			_region = region.ptr
+			_region = region.latLngBounds()
 		}
 
 		var _cacheDir *C.char
@@ -57,43 +55,48 @@ func NewMapSnapshotter(src FileSource,
 			_region,
 			_cacheDir)
 
-		return &MapSnapshotter{ptr:ptr}
+		return (*MapSnapshotter)(ptr)
+}
+
+func (ms *MapSnapshotter) mapSnapshotter() *C.MbglMapSnapshotter {
+	return (*C.MbglMapSnapshotter)(ms)
 }
 
-func (ms MapSnapshotter) Snapshot() *PremultipliedImage {
-	ptr := C.mbgl_map_snapshotter_snapshot(ms.ptr)
-	return &PremultipliedImage{ptr:ptr}
+func (ms *MapSnapshotter) Snapshot() *PremultipliedImage {
+	ptr := C.mbgl_map_snapshotter_snapshot(ms.mapSnapshotter())
+	return (*PremultipliedImage)(ptr)
 }
 
-func (ms MapSnapshotter) SetCameraOptions(camOpts CameraOptions) {
-	C.mbgl_map_snapshotter_set_camera_options(ms.ptr, camOpts.cPtr())
+func (ms *MapSnapshotter) SetCameraOptions(camOpts CameraOptions) {
+	C.mbgl_map_snapshotter_set_camera_options(ms.mapSnapshotter(), camOpts.cPtr())
 }
 
-func (ms MapSnapshotter) SetRegion(region *LatLngBounds) {
-	C.mbgl_map_snapshotter_set_region(ms.ptr, region.ptr)
+func (ms *MapSnapshotter) SetRegion(region *LatLngBounds) {
+	C.mbgl_map_snapshotter_set_region(ms.mapSnapshotter(), region.latLngBounds())
 }
 
-func (ms MapSnapshotter) SetStyleURL(style string) {
+func (ms *MapSnapshotter) SetStyleURL(style string) {
 	fmt.Println("setting style, ", style)
-	C.mbgl_map_snapshotter_set_style_url(ms.ptr, C.CString(style))
+	C.mbgl_map_snapshotter_set_style_url(ms.mapSnapshotter(), C.CString(style))
 	fmt.Println("style set")
 }
 
-func (ms MapSnapshotter) SetSize(size Size) {
-	C.mbgl_map_snapshotter_set_size(ms.ptr, size.cSize())
+func (ms *MapSnapshotter) SetSize(size Size) {
+	C.mbgl_map_snapshotter_set_size(ms.mapSnapshotter(), size.cSize())
 }
 
 func (ms *MapSnapshotter) Destruct() {
-	C.mbgl_map_snapshotter_destruct(ms.ptr)
-	ms.ptr = nil
+	C.mbgl_map_snapshotter_destruct(ms.mapSnapshotter())
 }
 
-type PremultipliedImage struct {
-	ptr *C.MbglPremultipliedImage
+type PremultipliedImage C.MbglPremultipliedImage
+
+func (im *PremultipliedImage) premultipliedImage() *C.MbglPremultipliedImage {
+	return (*C.MbglPremultipliedImage)(im)
 }
 
-func (im PremultipliedImage) Image() image.Image {
-	raw := C.mbgl_premultiplied_image_raw(im.ptr)
+func (im *PremultipliedImage) Image() image.Image {
+	raw := C.mbgl_premultiplied_image_raw(im.premultipliedImage())
 
 	bytes := int(raw.width) * int(raw.height) * 4
 
@@ -106,8 +109,7 @@ func (im PremultipliedImage) Image() image.Image {
 }
 
 func (im *PremultipliedImage) Destruct() {
-	C.mbgl_premultiplied_image_destruct(im.ptr)
-	im.ptr = nil
+	C.mbgl_premultiplied_image_destruct(im.premultipliedImage())
 }
 
 type img struct {

mbgl/map_snapshotter_test.go

@@ -8,6 +8,7 @@ import (
 	"github.com/go-spatial/geom/slippy"
 	"path/filepath"
 	"strings"
+	"github.com/arolek/p"
 )
 
 func TestNewMapSnapshotter(t *testing.T) {
@@ -38,7 +39,7 @@ func TestNewMapSnapshotter(t *testing.T) {
 
 	testcases := map[string]tcase{
 		"1": {
-			src:        NewDefaultFileSource("", "", nil),
+			src:        NewDefaultFileSource("", "", p.Uint64(0)),
 			sched:      NewThreadPool(4),
 			style:      "https://osm.tegola.io/maps/osm/style.json",
 			size:       Size{Width: 100, Height: 100},
@@ -94,7 +95,7 @@ func TestSnapshotterSnapshot(t *testing.T) {
 	testcases := map[string]tcase{
 		"1": {
 			ms: NewMapSnapshotter(
-				NewDefaultFileSource("", "", nil),
+				NewDefaultFileSource("", "", p.Uint64(0)),
 				tpool,
 				"https://osm.tegola.io/maps/osm/style.json",
 				Size{Height: 100, Width: 100},
@@ -122,7 +123,7 @@ func TestSnapshotterSetCamOpts(t *testing.T) {
 		SchedulerSetCurrent(tpool)
 
 		ms := NewMapSnapshotter(
-			NewDefaultFileSource("", "", nil),
+			NewDefaultFileSource("", "", p.Uint64(0)),
 			tpool,
 			"https://osm.tegola.io/maps/osm/style.json",
 			Size{Height: 100, Width: 100},
@@ -171,7 +172,7 @@ func TestSnapshotterSetRegion(t *testing.T) {
 		SchedulerSetCurrent(tpool)
 
 		ms := NewMapSnapshotter(
-			NewDefaultFileSource("","", nil),
+			NewDefaultFileSource("","", p.Uint64(0)),
 			tpool,
 			"https://osm.tegola.io/maps/osm/style.json",
 			Size{Height: 100, Width: 100},

mbgl/scheduler.go

@@ -12,16 +12,14 @@ type Scheduler interface {
 }
 
 // Satisfies the schduler inteface
-type scheduler struct {
-	ptr *C.MbglScheduler
-}
+type scheduler C.MbglScheduler
 
 func (s *scheduler) scheduler() *C.MbglScheduler {
-	return s.ptr
+	return (*C.MbglScheduler)(s)
 }
 
 func (s *scheduler) Destruct() {
-	C.mbgl_scheduler_destruct(s.ptr)
+	C.mbgl_scheduler_destruct(s.scheduler())
 }
 
 func SchedulerGetCurrent() Scheduler {
@@ -30,9 +28,7 @@ func SchedulerGetCurrent() Scheduler {
 		return nil
 	}
 
-	return &scheduler{
-		ptr: ptr,
-	}
+	return (*scheduler)(ptr)
 }
 
 func SchedulerSetCurrent(sched Scheduler) {

mbgl/thread_pool.go

@@ -6,28 +6,23 @@ package mbgl
  */
 import "C"
 
-type ThreadPool struct {
-	ptr *C.MbglThreadPool
-}
+type ThreadPool C.MbglThreadPool
 
 func NewThreadPool(threads int) (*ThreadPool) {
 	ptr := C.mbgl_thread_pool_new(C.int(threads))
 
-	return &ThreadPool{
-		ptr: ptr,
-	}
+	return (*ThreadPool)(ptr)
 }
 
-func (t ThreadPool) threadPool() *C.MbglThreadPool {
-	return t.ptr
+func (t *ThreadPool) threadPool() *C.MbglThreadPool {
+	return (*C.MbglThreadPool)(t)
 }
 
 // Scheduler is a prarent class
-func (t ThreadPool) scheduler() *C.MbglScheduler {
-	return (*C.MbglScheduler)(t.ptr)
+func (t *ThreadPool) scheduler() *C.MbglScheduler {
+	return (*C.MbglScheduler)(t)
 }
 
 func (t *ThreadPool) Destruct() {
-	C.mbgl_thread_pool_destruct(t.ptr)
-	t.ptr = nil
+	C.mbgl_thread_pool_destruct(t.threadPool())
 }