render/sdl/events.go

package sdl

import (
	"errors"
	"fmt"

	"git.kirsle.net/go/render/event"
	"github.com/veandco/go-sdl2/sdl"
)

// Debug certain SDL events
var (
	DebugWindowEvents = false
	DebugMouseEvents  = false
	DebugClickEvents  = false
	DebugKeyEvents    = false
)

// Poll for events.
func (r *Renderer) Poll() (*event.State, error) {
	s := r.events

	// Reset some events.
	s.WindowResized = false

	// helper function to push keyboard key names on keyDown events only.
	pushKey := func(name string, state uint8) {
		s.SetKeyDown(name, state == 1)
	}

	for event := sdl.PollEvent(); event != nil; event = sdl.PollEvent() {
		switch t := event.(type) {
		case *sdl.QuitEvent:
			return s, errors.New("quit")
		case *sdl.WindowEvent:
			if DebugWindowEvents {
				if t.Event == sdl.WINDOWEVENT_RESIZED {
					fmt.Printf("[%d ms] tick:%d Window Resized to %dx%d",
						t.Timestamp,
						r.ticks,
						t.Data1,
						t.Data2,
					)
				}
			}

			if t.Event == sdl.WINDOWEVENT_RESIZED {
				s.WindowResized = true
			}
		case *sdl.MouseMotionEvent:
			if DebugMouseEvents {
				fmt.Printf("[%d ms] tick:%d MouseMotion  type:%d  id:%d  x:%d  y:%d  xrel:%d  yrel:%d",
					t.Timestamp, r.ticks, t.Type, t.Which, t.X, t.Y, t.XRel, t.YRel,
				)
			}

			// Push the cursor position.
			s.CursorX = int(t.X)
			s.CursorY = int(t.Y)
		case *sdl.MouseButtonEvent:
			if DebugClickEvents {
				fmt.Printf("[%d ms] tick:%d MouseButton  type:%d  id:%d  x:%d  y:%d  button:%d  state:%d\n",
					t.Timestamp, r.ticks, t.Type, t.Which, t.X, t.Y, t.Button, t.State,
				)
			}

			// Push the cursor position.
			s.CursorX = int(t.X)
			s.CursorY = int(t.Y)

			// Store the clicked state of the mouse button.
			if t.Button == 1 {
				s.Button1 = t.State == 1
			} else if t.Button == 2 {
				s.Button2 = t.State == 1
			} else if t.Button == 3 {
				s.Button3 = t.State == 1
			}
			//
			// // Is a mouse button pressed down?
			// checkDown := func(number uint8, target *events.BoolTick) bool {
			// 	if t.Button == number {
			// 		var eventName string
			// 		if t.State == 1 && target.Now == false {
			// 			eventName = "DOWN"
			// 		} else if t.State == 0 && target.Now == true {
			// 			eventName = "UP"
			// 		}
			//
			// 		if eventName != "" {
			// 			target.Push(eventName == "DOWN")
			// 		}
			// 		return true
			// 	}
			// 	return false
			// }
			//
			// if checkDown(1, s.Button1) || checkDown(3, s.Button2) || checkDown(2, s.Button3) {
			// 	// Return the event immediately.
			// 	return s, nil
			// }
		case *sdl.MouseWheelEvent:
			if DebugMouseEvents {
				fmt.Printf("[%d ms] tick:%d MouseWheel  type:%d  id:%d  x:%d  y:%d",
					t.Timestamp, r.ticks, t.Type, t.Which, t.X, t.Y,
				)
			}
		case *sdl.KeyboardEvent:
			if DebugKeyEvents {
				fmt.Printf("[%d ms] tick:%d Keyboard  type:%d  sym:%c  modifiers:%d  state:%d  repeat:%d\n",
					t.Timestamp, r.ticks, t.Type, t.Keysym.Sym, t.Keysym.Mod, t.State, t.Repeat,
				)
			}

			switch t.Keysym.Scancode {
			case sdl.SCANCODE_ESCAPE:
				if t.Repeat == 1 {
					continue
				}
				s.Escape = t.State == 1
			case sdl.SCANCODE_RETURN:
				if t.Repeat == 1 {
					continue
				}
				s.Enter = t.State == 1
			case sdl.SCANCODE_F1:
				pushKey("F1", t.State)
			case sdl.SCANCODE_F2:
				pushKey("F2", t.State)
			case sdl.SCANCODE_F3:
				pushKey("F3", t.State)
			case sdl.SCANCODE_F4:
				pushKey("F4", t.State)
			case sdl.SCANCODE_F5:
				pushKey("F5", t.State)
			case sdl.SCANCODE_F6:
				pushKey("F6", t.State)
			case sdl.SCANCODE_F7:
				pushKey("F7", t.State)
			case sdl.SCANCODE_F8:
				pushKey("F8", t.State)
			case sdl.SCANCODE_F9:
				pushKey("F9", t.State)
			case sdl.SCANCODE_F10:
				pushKey("F10", t.State)
			case sdl.SCANCODE_F11:
				pushKey("F11", t.State)
			case sdl.SCANCODE_F12:
				pushKey("F12", t.State)
			case sdl.SCANCODE_UP:
				s.Up = t.State == 1
			case sdl.SCANCODE_LEFT:
				s.Left = t.State == 1
			case sdl.SCANCODE_RIGHT:
				s.Right = t.State == 1
			case sdl.SCANCODE_DOWN:
				s.Down = t.State == 1
			case sdl.SCANCODE_LSHIFT:
				fallthrough
			case sdl.SCANCODE_RSHIFT:
				s.Shift = t.State == 1
			case sdl.SCANCODE_LALT:
			case sdl.SCANCODE_RALT:
				s.Alt = t.State == 1
			case sdl.SCANCODE_LCTRL:
				s.Ctrl = t.State == 1
			case sdl.SCANCODE_RCTRL:
				s.Ctrl = t.State == 1
			case sdl.SCANCODE_BACKSPACE:
				// Make it a key event with "\b" as the sequence.
				s.SetKeyDown(`\b`, t.State == 1 || t.Repeat == 1)
			default:
				// Push the string value of the key.
				s.SetKeyDown(string(t.Keysym.Sym), t.State == 1)
			}
		}
	}

	return s, nil
}