refactor window creation

main.go

@@ -12,6 +12,7 @@ import "C"
 
 import (
 	"encoding/binary"
+	"errors"
 	"io"
 	"os"
 	"unsafe"
@@ -19,6 +20,48 @@ import (
 
 const bufSize uint = 2048
 
+type milkDropWindow struct {
+	window  *sdl.Window
+	context sdl.GLContext
+	handle  C.projectm_handle
+}
+
+func newMilkDropWindow(width, height int32) (*milkDropWindow, error) {
+	var m milkDropWindow
+	var err error
+
+	m.window, err = sdl.CreateWindow("milkbucket", sdl.WINDOWPOS_UNDEFINED, sdl.WINDOWPOS_UNDEFINED, width, height, sdl.WINDOW_OPENGL|sdl.WINDOW_RESIZABLE)
+	if err != nil {
+		return &m, err
+	}
+
+	m.context, err = m.window.GLCreateContext()
+	if err != nil {
+		return &m, err
+	}
+
+	m.handle = C.projectm_create()
+	if m.handle == nil {
+		return &m, errors.New("error creating projectM instance")
+	}
+
+	C.projectm_set_window_size(m.handle, C.ulong(width), C.ulong(height))
+
+	return &m, nil
+}
+
+func (m *milkDropWindow) destroy() {
+	C.projectm_destroy(m.handle)
+	sdl.GLDeleteContext(m.context)
+	m.window.Destroy()
+}
+
+func (m *milkDropWindow) loadPreset(preset string) {
+	cPreset := C.CString("/usr/share/projectM/presets/presets_stock/Zylot - Wisps.milk")
+	defer C.free(unsafe.Pointer(cPreset))
+	C.projectm_load_preset_file(m.handle, cPreset, false)
+}
+
 func render(window *sdl.Window, handle C.projectm_handle) (bool, error) {
 	var audioData [bufSize]int16
 
@@ -58,43 +101,24 @@ func handleEvent(event sdl.Event, handle C.projectm_handle) bool {
 }
 
 func main() {
-	windowWidth := 800
-	windowHeight := 600
-
 	err := sdl.Init(sdl.INIT_VIDEO)
 	if err != nil {
 		panic(err)
 	}
 	defer sdl.Quit()
 
-	window, err := sdl.CreateWindow("milkbucket", sdl.WINDOWPOS_UNDEFINED, sdl.WINDOWPOS_UNDEFINED, int32(windowWidth), int32(windowHeight), sdl.WINDOW_OPENGL|sdl.WINDOW_RESIZABLE)
+	m, err := newMilkDropWindow(800, 600)
 	if err != nil {
 		panic(err)
 	}
-	defer window.Destroy()
+	defer m.destroy()
 
-	context, err := window.GLCreateContext()
-	if err != nil {
-		panic(err)
-	}
-	defer sdl.GLDeleteContext(context)
-
-	handle := C.projectm_create()
-	if handle == nil {
-		panic("nil")
-	}
-	defer C.projectm_destroy(handle)
-
-	C.projectm_set_window_size(handle, C.ulong(windowWidth), C.ulong(windowHeight))
-
-	preset := C.CString("/usr/share/projectM/presets/presets_stock/Zylot - Wisps.milk")
-	defer C.free(unsafe.Pointer(preset))
-	C.projectm_load_preset_file(handle, preset, false)
+	m.loadPreset("/usr/share/projectM/presets/presets_stock/Zylot - Wisps.milk")
 
 	running := true
 	for running {
 		for event := sdl.PollEvent(); event != nil; event = sdl.PollEvent() {
-			running = handleEvent(event, handle)
+			running = handleEvent(event, m.handle)
 			if !running {
 				break
 			}
@@ -104,7 +128,7 @@ func main() {
 			break
 		}
 
-		running, err = render(window, handle)
+		running, err = render(m.window, m.handle)
 		if err != nil {
 			panic(err)
 		}