Stabilize frame rate, add debug overlay

.gitignore

@@ -0,0 +1 @@
+fonts/

README.md

@@ -20,3 +20,11 @@ As a rough idea of the milestones needed for this game to work:
 * [ ] Start implementing a platformer that uses the custom map format for its
   rendering and collision detection.
 * [ ] ???
+
+# Building
+
+Fedora dependencies:
+
+```bash
+$ sudo dnf install SDL2-devel SDL2_ttf-devel
+```

cmd/doodle/main.go

@@ -4,7 +4,7 @@ import (
 	"flag"
 	"runtime"
 
-	"github.com/kirsle/doodle"
+	"git.kirsle.net/apps/doodle"
 )
 
 // Build number is the git commit hash.

config.go

@@ -0,0 +1,11 @@
+package doodle
+
+import "github.com/veandco/go-sdl2/sdl"
+
+// Configuration constants.
+var (
+	DebugTextPadding int32 = 8
+	DebugTextSize          = 24
+	DebugTextColor         = sdl.Color{255, 153, 255, 255}
+	DebugTextOutline       = sdl.Color{0, 0, 0, 255}
+)

doodle.go

@@ -2,59 +2,81 @@ package doodle
 
 import (
 	"fmt"
+	"time"
 
+	"git.kirsle.net/apps/doodle/events"
+	"git.kirsle.net/apps/doodle/render"
+	"github.com/kirsle/golog"
 	"github.com/veandco/go-sdl2/sdl"
+	"github.com/veandco/go-sdl2/ttf"
 )
 
-// Version number.
-const Version = "0.0.0-alpha"
+const (
+	// Version number.
+	Version = "0.0.0-alpha"
+
+	// TargetFPS is the frame rate to cap the game to.
+	TargetFPS = uint32(1000 / 60) // 60 FPS
+
+	// Millisecond64 is a time.Millisecond casted to float64.
+	Millisecond64 = float64(time.Millisecond)
+)
 
 // Doodle is the game object.
 type Doodle struct {
 	Debug bool
 
+	startTime time.Time
 	running   bool
-	events  EventState
-	width   int
-	height  int
+	events    *events.State
+	width     int32
+	height    int32
+
+	nextSecond time.Time
+	canvas     Grid
 
 	window   *sdl.Window
-	surface  *sdl.Surface
 	renderer *sdl.Renderer
 }
 
-// EventState keeps track of important events.
-type EventState struct {
-	CursorX    int32
-	CursorY    int32
-	LastX      int32
-	LastY      int32
-	LeftClick  bool
-	LastLeft   bool
-	RightClick bool
-	LastRight  bool
-}
-
 // New initializes the game object.
 func New(debug bool) *Doodle {
 	d := &Doodle{
 		Debug:     debug,
+		startTime: time.Now(),
+		events:    events.New(),
 		running:   true,
 		width:     800,
 		height:    600,
+		canvas:    Grid{},
+
+		nextSecond: time.Now().Add(1 * time.Second),
 	}
+
+	if !debug {
+		log.Config.Level = golog.InfoLevel
+	}
+
 	return d
 }
 
 // Run initializes SDL and starts the main loop.
 func (d *Doodle) Run() error {
 	// Initialize SDL.
+	log.Info("Initializing SDL")
 	if err := sdl.Init(sdl.INIT_EVERYTHING); err != nil {
 		return err
 	}
 	defer sdl.Quit()
 
+	// Initialize SDL_TTF.
+	log.Info("Initializing SDL_TTF")
+	if err := ttf.Init(); err != nil {
+		return err
+	}
+
 	// Create our window.
+	log.Info("Creating the Main Window")
 	window, err := sdl.CreateWindow(
 		"Doodle v"+Version,
 		sdl.WINDOWPOS_CENTERED,
@@ -70,56 +92,33 @@ func (d *Doodle) Run() error {
 	d.window = window
 
 	// Blank out the window in white.
+	log.Info("Creating the SDL Renderer")
 	renderer, err := sdl.CreateRenderer(window, -1, sdl.RENDERER_ACCELERATED)
 	if err != nil {
 		panic(err)
 	}
 	d.renderer = renderer
+	render.Renderer = renderer
 	defer renderer.Destroy()
 
-	for i := 0; i < 10; i++ {
-		d.Loop()
-		// renderer.Clear()
-		// rect := sdl.Rect{
-		// 	X: 0,
-		// 	Y: 0,
-		// 	W: 800,
-		// 	H: 600,
-		// }
-		// renderer.SetDrawColor(0, 0, 0, 255)
-		// renderer.FillRect(&rect)
-		//
-		// renderer.SetDrawColor(0, 255, 0, 255)
-		// renderer.DrawPoint(10*i, 10*i)
-		//
-		// renderer.Present()
-		//
-		// sdl.Delay(250)
-	}
-
+	log.Info("Enter Main Loop")
 	for d.running {
+		// Draw a frame and log how long it took.
+		start := time.Now()
 		err = d.Loop()
+		elapsed := time.Now().Sub(start)
+
+		tmp := elapsed / time.Millisecond
+		delay := TargetFPS - uint32(tmp)
+		sdl.Delay(delay)
+
+		d.TrackFPS(delay)
 		if err != nil {
 			return err
 		}
 	}
 
-	// surface, err := window.GetSurface()
-	// if err != nil {
-	// 	panic(err)
-	// }
-	// d.surface = surface
-	//
-	// rect := sdl.Rect{
-	// 	X: 0,
-	// 	Y: 0,
-	// 	W: 200,
-	// 	H: 200,
-	// }
-	// surface.FillRect(&rect, 0xffff0000)
-	// window.UpdateSurface()
-	//
-	// sdl.Delay(2500)
+	log.Warn("Main Loop Exited! Shutting down...")
 	return nil
 }
 
@@ -128,117 +127,72 @@ type Pixel struct {
 	start bool
 	x     int32
 	y     int32
+	dx    int32
+	dy    int32
 }
 
+func (p Pixel) String() string {
+	return fmt.Sprintf("(%d,%d) delta (%d,%d)",
+		p.x, p.y,
+		p.dx, p.dy,
+	)
+}
+
+// Grid is a 2D grid of pixels in X,Y notation.
+type Grid map[Pixel]interface{}
+
 var pixelHistory []Pixel
 
 // Loop runs one loop of the game engine.
 func (d *Doodle) Loop() error {
 	// Poll for events.
-	d.PollEvents()
-
-	d.renderer.Clear()
-	rect := sdl.Rect{
-		X: 0,
-		Y: 0,
-		W: 800,
-		H: 600,
+	ev, err := d.events.Poll()
+	if err != nil {
+		log.Error("event poll error: %s", err)
+		return err
 	}
+
+	// Clear the canvas and fill it with white.
 	d.renderer.SetDrawColor(255, 255, 255, 255)
-	d.renderer.FillRect(&rect)
+	d.renderer.Clear()
 
 	// Clicking? Log all the pixels while doing so.
-	if d.events.LeftClick {
-		fmt.Printf("Pixel at %dx%d\n", d.events.CursorX, d.events.CursorY)
+	if ev.Button1.Now {
 		pixel := Pixel{
-			start: d.events.LeftClick && !d.events.LastLeft,
-			x:     d.events.CursorX,
-			y:     d.events.CursorY,
+			start: ev.Button1.Now && !ev.Button1.Last,
+			x:     ev.CursorX.Now,
+			y:     ev.CursorY.Now,
+			dx:    ev.CursorX.Last,
+			dy:    ev.CursorY.Last,
 		}
+
+		if len(pixelHistory) == 0 || pixelHistory[len(pixelHistory)-1] != pixel {
 			pixelHistory = append(pixelHistory, pixel)
 		}
+	}
 
-	// Colorize all those pixels.
 	d.renderer.SetDrawColor(0, 0, 0, 255)
 	for i, pixel := range pixelHistory {
-		fmt.Printf("Draw: %v\n", pixel)
-		if pixel.start == false && i > 0 {
-			start := pixelHistory[i-1]
-			fmt.Printf("Line from %dx%d -> %dx%d\n", start.x, start.y, pixel.x, pixel.y)
-			d.renderer.DrawLine(
-				int(start.x),
-				int(start.y),
-				int(pixel.x),
-				int(pixel.y),
-			)
+		if !pixel.start && i > 0 {
+			prev := pixelHistory[i-1]
+			if prev.x == pixel.x && prev.y == pixel.y {
+				d.renderer.DrawPoint(pixel.x, pixel.y)
 			} else {
-			d.renderer.DrawPoint(
-				int(pixel.x), int(pixel.y),
+				d.renderer.DrawLine(
+					pixel.x,
+					pixel.y,
+					prev.x,
+					prev.y,
 				)
 			}
-		// d.renderer.FillRect(&sdl.Rect{pixel.x, pixel.y, 10, 10})
+		}
+		d.renderer.DrawPoint(pixel.x, pixel.y)
 	}
 
+	// Draw the FPS.
+	d.DrawDebugOverlay()
+
 	d.renderer.Present()
-	sdl.Delay(1000 / 60)
 
 	return nil
 }
-
-// PollEvents checks for keyboard/mouse/etc. events.
-func (d *Doodle) PollEvents() {
-	for {
-		event := sdl.PollEvent()
-		if event == nil {
-			break
-		}
-
-		// Handle the event.
-		switch t := event.(type) {
-		case *sdl.QuitEvent:
-			d.running = false
-		case *sdl.MouseMotionEvent:
-			fmt.Printf("[%d ms] MouseMotion  type:%d  id:%d  x:%d  y:%d  xrel:%d  yrel:%d\n",
-				t.Timestamp, t.Type, t.Which, t.X, t.Y, t.XRel, t.YRel,
-			)
-			d.events.LastX = d.events.CursorX
-			d.events.LastY = d.events.CursorY
-			d.events.CursorX = t.X
-			d.events.CursorY = t.Y
-		case *sdl.MouseButtonEvent:
-			fmt.Printf("[%d ms] MouseButton  type:%d  id:%d  x:%d  y:%d  button:%d  state:%d\n",
-				t.Timestamp, t.Type, t.Which, t.X, t.Y, t.Button, t.State,
-			)
-
-			d.events.LastX = d.events.CursorX
-			d.events.LastY = d.events.CursorY
-			d.events.CursorX = t.X
-			d.events.CursorY = t.Y
-
-			d.events.LastLeft = d.events.LeftClick
-			d.events.LastRight = d.events.RightClick
-
-			// Clicking?
-			if t.Button == 1 {
-				if t.State == 1 && d.events.LeftClick == false {
-					d.events.LeftClick = true
-				} else if t.State == 0 && d.events.LeftClick == true {
-					d.events.LeftClick = false
-				}
-			}
-			d.events.RightClick = t.Button == 3 && t.State == 1
-		case *sdl.MouseWheelEvent:
-			fmt.Printf("[%d ms] MouseWheel  type:%d  id:%d  x:%d  y:%d\n",
-				t.Timestamp, t.Type, t.Which, t.X, t.Y,
-			)
-		case *sdl.KeyDownEvent:
-			fmt.Printf("[%d ms] Keyboard  type:%d  sym:%c  modifiers:%d  state:%d  repeat:%d\n",
-				t.Timestamp, t.Type, t.Keysym.Sym, t.Keysym.Mod, t.State, t.Repeat,
-			)
-		case *sdl.KeyUpEvent:
-			fmt.Printf("[%d ms] Keyboard  type:%d  sym:%c  modifiers:%d  state:%d  repeat:%d\n",
-				t.Timestamp, t.Type, t.Keysym.Sym, t.Keysym.Mod, t.State, t.Repeat,
-			)
-		}
-	}
-}

events/debug.go

@@ -0,0 +1,7 @@
+package events
+
+// Debug constants, toggle on or off for SUPER VERBOSE debugging.
+var (
+	DebugMouseEvents = false
+	DebugClickEvents = true
+)

events/events.go

@@ -0,0 +1,81 @@
+// Package events manages mouse and keyboard SDL events for Doodle.
+package events
+
+import (
+	"errors"
+
+	"github.com/veandco/go-sdl2/sdl"
+)
+
+// State keeps track of event states.
+type State struct {
+	// Mouse buttons.
+	Button1 BoolFrameState
+	Button2 BoolFrameState
+
+	// Cursor positions.
+	CursorX Int32FrameState
+	CursorY Int32FrameState
+}
+
+// New creates a new event state manager.
+func New() *State {
+	return &State{}
+}
+
+// Poll for events.
+func (s *State) Poll() (*State, error) {
+	for event := sdl.PollEvent(); event != nil; event = sdl.PollEvent() {
+		switch t := event.(type) {
+		case *sdl.QuitEvent:
+			return s, errors.New("quit")
+		case *sdl.MouseMotionEvent:
+			if DebugMouseEvents {
+				log.Debug("[%d ms] MouseMotion  type:%d  id:%d  x:%d  y:%d  xrel:%d  yrel:%d",
+					t.Timestamp, t.Type, t.Which, t.X, t.Y, t.XRel, t.YRel,
+				)
+			}
+
+			// Push the cursor position.
+			s.CursorX.Push(t.X)
+			s.CursorY.Push(t.Y)
+			s.Button1.Push(t.State == 1)
+		case *sdl.MouseButtonEvent:
+			if DebugClickEvents {
+				log.Debug("[%d ms] MouseButton  type:%d  id:%d  x:%d  y:%d  button:%d  state:%d",
+					t.Timestamp, t.Type, t.Which, t.X, t.Y, t.Button, t.State,
+				)
+			}
+
+			// Push the cursor position.
+			s.CursorX.Push(t.X)
+			s.CursorY.Push(t.Y)
+
+			// Is a mouse button pressed down?
+			if t.Button == 1 {
+				if DebugClickEvents {
+					if t.State == 1 && s.Button1.Now == false {
+						log.Debug("Mouse Button1 DOWN")
+					} else if t.State == 0 && s.Button1.Now == true {
+						log.Debug("Mouse Button1 UP")
+					}
+				}
+				s.Button1.Push(t.State == 1)
+			}
+
+			s.Button2.Push(t.Button == 3 && t.State == 1)
+		case *sdl.MouseWheelEvent:
+			if DebugMouseEvents {
+				log.Debug("[%d ms] MouseWheel  type:%d  id:%d  x:%d  y:%d",
+					t.Timestamp, t.Type, t.Which, t.X, t.Y,
+				)
+			}
+		case *sdl.KeyboardEvent:
+			log.Debug("[%d ms] Keyboard  type:%d  sym:%c  modifiers:%d  state:%d  repeat:%d\n",
+				t.Timestamp, t.Type, t.Keysym.Sym, t.Keysym.Mod, t.State, t.Repeat,
+			)
+		}
+	}
+
+	return s, nil
+}

events/log.go

@@ -0,0 +1,9 @@
+package events
+
+import "github.com/kirsle/golog"
+
+var log *golog.Logger
+
+func init() {
+	log = golog.GetLogger("doodle")
+}

events/types.go

@@ -0,0 +1,25 @@
+package events
+
+// BoolFrameState holds boolean state between this frame and the previous.
+type BoolFrameState struct {
+	Now  bool
+	Last bool
+}
+
+// Int32FrameState manages int32 state between this frame and the previous.
+type Int32FrameState struct {
+	Now  int32
+	Last int32
+}
+
+// Push a bool state, copying the current Now value to Last.
+func (bs *BoolFrameState) Push(v bool) {
+	bs.Last = bs.Now
+	bs.Now = v
+}
+
+// Push an int32 state, copying the current Now value to Last.
+func (is *Int32FrameState) Push(v int32) {
+	is.Last = is.Now
+	is.Now = v
+}

fps.go

@@ -0,0 +1,70 @@
+package doodle
+
+import (
+	"fmt"
+	"time"
+
+	"git.kirsle.net/apps/doodle/render"
+	"github.com/veandco/go-sdl2/sdl"
+)
+
+// Frames to cache for FPS calculation.
+const maxSamples = 100
+
+var (
+	fpsCurrentTicks uint32 // current time we get sdl.GetTicks()
+	fpsLastTime     uint32 // last time we printed the fpsCurrentTicks
+	fpsCurrent      int
+	fpsFrames       int
+	fpsSkipped      uint32
+	fpsInterval     uint32 = 1000
+)
+
+// DrawDebugOverlay draws the debug FPS text on the SDL canvas.
+func (d *Doodle) DrawDebugOverlay() {
+	if !d.Debug {
+		return
+	}
+
+	text := fmt.Sprintf(
+		"FPS: %d (%dms)    (X,Y)=(%d,%d)  canvas=%d",
+		fpsCurrent,
+		fpsSkipped,
+		d.events.CursorX.Now,
+		d.events.CursorY.Now,
+		len(pixelHistory),
+	)
+	render.StrokedText(render.TextConfig{
+		Text:        text,
+		Size:        DebugTextSize,
+		Color:       DebugTextColor,
+		StrokeColor: DebugTextOutline,
+		X:           DebugTextPadding,
+		Y:           DebugTextPadding,
+	})
+}
+
+// TrackFPS shows the current FPS once per second.
+func (d *Doodle) TrackFPS(skipped uint32) {
+	fpsFrames++
+	fpsCurrentTicks = sdl.GetTicks()
+
+	// Skip the first second.
+	if fpsCurrentTicks < fpsInterval {
+		return
+	}
+
+	if fpsLastTime < fpsCurrentTicks-fpsInterval {
+		log.Debug("Uptime: %s  FPS: %d   deltaTicks: %d   skipped: %dms",
+			time.Now().Sub(d.startTime),
+			fpsCurrent,
+			fpsCurrentTicks-fpsLastTime,
+			skipped,
+		)
+
+		fpsLastTime = fpsCurrentTicks
+		fpsCurrent = fpsFrames
+		fpsFrames = 0
+		fpsSkipped = skipped
+	}
+}

log.go

@@ -0,0 +1,14 @@
+package doodle
+
+import "github.com/kirsle/golog"
+
+var log *golog.Logger
+
+func init() {
+	log = golog.GetLogger("doodle")
+	log.Configure(&golog.Config{
+		Level:  golog.DebugLevel,
+		Theme:  golog.DarkTheme,
+		Colors: golog.ExtendedColor,
+	})
+}

render/log.go

@@ -0,0 +1,14 @@
+package render
+
+import "github.com/kirsle/golog"
+
+var log *golog.Logger
+
+func init() {
+	log = golog.GetLogger("doodle")
+	log.Configure(&golog.Config{
+		Level:  golog.DebugLevel,
+		Theme:  golog.DarkTheme,
+		Colors: golog.ExtendedColor,
+	})
+}

render/render.go

@@ -0,0 +1,7 @@
+// Package render manages the SDL rendering context for Doodle.
+package render
+
+import "github.com/veandco/go-sdl2/sdl"
+
+// Renderer is a singleton instance of the SDL renderer.
+var Renderer *sdl.Renderer

render/text.go

@@ -0,0 +1,89 @@
+package render
+
+import (
+	"github.com/veandco/go-sdl2/sdl"
+	"github.com/veandco/go-sdl2/ttf"
+)
+
+var fonts map[int]*ttf.Font = map[int]*ttf.Font{}
+
+// LoadFont loads and caches the font at a given size.
+func LoadFont(size int) (*ttf.Font, error) {
+	if font, ok := fonts[size]; ok {
+		return font, nil
+	}
+
+	font, err := ttf.OpenFont("./fonts/DejaVuSansMono.ttf", size)
+	if err != nil {
+		return nil, err
+	}
+	fonts[size] = font
+
+	return font, nil
+}
+
+// TextConfig are settings for rendered text.
+type TextConfig struct {
+	Text        string
+	Size        int
+	Color       sdl.Color
+	StrokeColor sdl.Color
+	X           int32
+	Y           int32
+	W           int32
+	H           int32
+}
+
+// StrokedText draws text with a stroke color around it.
+func StrokedText(t TextConfig) {
+	stroke := func(copy TextConfig, x, y int32) {
+		copy.Color = t.StrokeColor
+		copy.X += x
+		copy.Y += y
+		Text(copy)
+	}
+
+	stroke(t, -1, -1)
+	stroke(t, -1, 0)
+	stroke(t, -1, 1)
+
+	stroke(t, 1, -1)
+	stroke(t, 1, 0)
+	stroke(t, 1, 1)
+
+	stroke(t, 0, -1)
+	stroke(t, 0, 1)
+	Text(t)
+}
+
+// Text draws text on the renderer.
+func Text(t TextConfig) error {
+	var (
+		font    *ttf.Font
+		surface *sdl.Surface
+		tex     *sdl.Texture
+		err     error
+	)
+
+	if font, err = LoadFont(t.Size); err != nil {
+		return err
+	}
+
+	if surface, err = font.RenderUTF8Blended(t.Text, t.Color); err != nil {
+		return err
+	}
+	defer surface.Free()
+
+	if tex, err = Renderer.CreateTextureFromSurface(surface); err != nil {
+		return err
+	}
+	defer tex.Destroy()
+
+	Renderer.Copy(tex, nil, &sdl.Rect{
+		X: int32(t.X),
+		Y: int32(t.Y),
+		W: int32(surface.W),
+		H: int32(surface.H),
+	})
+	return nil
+}