added explicit insert/draw mode, left mouse by default moves canvas

README.md

@@ -76,7 +76,10 @@ While it runs, there are a couple of commands you can use:
 * page up: speed up
 * page down: slow down
 * Mouse wheel: zoom in or out
-* move mouse while middle mouse button pressed: move canvas
+* move mouse while left mouse button pressed: move canvas
+* i: enter "insert" (draw) mode: use left mouse to set cells alife and right
+  button to dead. Leave with "space". While in insert mode, use middle mouse
+  button to drag grid.
 * r: reset to 1:1 zoom
 * escape: open menu
 * s: save game state to file (can be loaded with -l)

src/config.go

@@ -15,24 +15,24 @@ import (
 
 // all the settings comming from commandline, but maybe tweaked later from the UI
 type Config struct {
-	Width, Height, Cellsize, Density       int // measurements
+	Width, Height, Cellsize, Density                 int // measurements
-	ScreenWidth, ScreenHeight              int
+	ScreenWidth, ScreenHeight                        int
-	TPG                                    int      // ticks per generation/game speed, 1==max
+	TPG                                              int      // ticks per generation/game speed, 1==max
-	Debug, Empty, Invert, Paused, Markmode bool     // game modi
+	Debug, Empty, Invert, Paused, Markmode, Drawmode bool     // game modi
-	ShowEvolution, ShowGrid, RunOneStep    bool     // flags
+	ShowEvolution, ShowGrid, RunOneStep              bool     // flags
-	Rule                                   *Rule    // which rule to use, default: B3/S23
+	Rule                                             *Rule    // which rule to use, default: B3/S23
-	RLE                                    *rle.RLE // loaded GOL pattern from RLE file
+	RLE                                              *rle.RLE // loaded GOL pattern from RLE file
-	Statefile                              string   // load game state from it if non-nil
+	Statefile                                        string   // load game state from it if non-nil
-	StateGrid                              *Grid    // a grid from a statefile
+	StateGrid                                        *Grid    // a grid from a statefile
-	Wrap                                   bool     // wether wraparound mode is in place or not
+	Wrap                                             bool     // wether wraparound mode is in place or not
-	ShowVersion                            bool
+	ShowVersion                                      bool
-	UseShader                              bool // to use a shader to render alife cells
+	UseShader                                        bool // to use a shader to render alife cells
-	Restart, RestartGrid, RestartCache     bool
+	Restart, RestartGrid, RestartCache               bool
-	StartWithMenu                          bool
+	StartWithMenu                                    bool
-	Zoomfactor                             int
+	Zoomfactor                                       int
-	ZoomOutFactor                          int
+	ZoomOutFactor                                    int
-	InitialCamPos                          []float64
+	InitialCamPos                                    []float64
-	DelayedStart                           bool // if true game, we wait. like pause but program induced
+	DelayedStart                                     bool // if true game, we wait. like pause but program induced
 
 	// for internal profiling
 	ProfileFile     string

src/play.go

@@ -48,7 +48,7 @@ type ScenePlay struct {
 	MarkDone                                   bool          // true when mouse1 released, copy cells between Mark+Point
 	Mark, Point                                image.Point   // area to marks+save
 	RunOneStep                                 bool          // mutable flags from config
-	TPG                                        int
+	TPG                                        int           // current game speed (ticks per game)
 }
 
 func NewPlayScene(game *Game, config *Config) Scene {
@@ -188,6 +188,11 @@ func (scene *ScenePlay) CheckInput() {
 		scene.Config.Paused = true
 	}
 
+	if inpututil.IsKeyJustPressed(ebiten.KeyI) {
+		scene.Config.Drawmode = true
+		scene.Config.Paused = true
+	}
+
 	if scene.Config.Markmode {
 		return
 	}
@@ -196,16 +201,6 @@ func (scene *ScenePlay) CheckInput() {
 		scene.Config.TogglePaused()
 	}
 
-	if ebiten.IsMouseButtonPressed(ebiten.MouseButtonLeft) {
-		scene.ToggleCellOnCursorPos(Alive)
-		scene.Config.Paused = true // drawing while running makes no sense
-	}
-
-	if ebiten.IsMouseButtonPressed(ebiten.MouseButtonRight) {
-		scene.ToggleCellOnCursorPos(Dead)
-		scene.Config.Paused = true // drawing while running makes no sense
-	}
-
 	if inpututil.IsKeyJustPressed(ebiten.KeyPageDown) {
 		if scene.TPG < 120 {
 			scene.TPG++
@@ -233,6 +228,22 @@ func (scene *ScenePlay) CheckInput() {
 	}
 }
 
+func (scene *ScenePlay) CheckDrawingInput() {
+	if scene.Config.Drawmode {
+		if ebiten.IsMouseButtonPressed(ebiten.MouseButtonLeft) {
+			scene.ToggleCellOnCursorPos(Alive)
+		}
+
+		if ebiten.IsMouseButtonPressed(ebiten.MouseButtonRight) {
+			scene.ToggleCellOnCursorPos(Dead)
+		}
+
+		if inpututil.IsKeyJustPressed(ebiten.KeyEscape) {
+			scene.Config.Drawmode = false
+		}
+	}
+}
+
 // Check dragging input.  move the canvas with the  mouse while pressing
 // the middle mouse button, zoom in and out using the wheel.
 func (scene *ScenePlay) CheckDraggingInput() {
@@ -240,13 +251,19 @@ func (scene *ScenePlay) CheckDraggingInput() {
 		return
 	}
 
+	dragbutton := ebiten.MouseButtonLeft
+
+	if scene.Config.Drawmode {
+		dragbutton = ebiten.MouseButtonMiddle
+	}
+
 	// move canvas
-	if scene.Dragging && !ebiten.IsMouseButtonPressed(ebiten.MouseButton1) {
+	if scene.Dragging && !ebiten.IsMouseButtonPressed(dragbutton) {
 		// release
 		scene.Dragging = false
 	}
 
-	if !scene.Dragging && ebiten.IsMouseButtonPressed(ebiten.MouseButton1) {
+	if !scene.Dragging && ebiten.IsMouseButtonPressed(dragbutton) {
 		// start dragging
 		scene.Dragging = true
 		scene.LastCursorPos[0], scene.LastCursorPos[1] = ebiten.CursorPosition()
@@ -408,6 +425,7 @@ func (scene *ScenePlay) Update() error {
 	}
 
 	scene.CheckInput()
+	scene.CheckDrawingInput()
 	scene.CheckDraggingInput()
 	scene.CheckMarkInput()
 
@@ -519,6 +537,10 @@ func (scene *ScenePlay) DrawDebug(screen *ebiten.Image) {
 			paused = "-- mark --"
 		}
 
+		if scene.Config.Drawmode {
+			paused = "-- insert --"
+		}
+
 		x, y := ebiten.CursorPosition()
 		debug := fmt.Sprintf(
 			DEBUG_FORMAT,