Coyote time

Changes.md

@@ -1,5 +1,41 @@
 # Changes
 
+## v0.14.0 TBD
+
+Level screenshots and thumbnails:
+
+* Level files will begin to take thumbnail screenshots of themselves and
+  store them as PNG images embedded with the level data, and are displayed
+  on the Story Mode level select screen.
+    * A thumbnail is saved the first time your level is saved, and can be
+      viewed and re-computed in the Level->Level Properties window of the
+      editor.
+    * Tip: for bounded levels when you want to screenshot the bottom edge,
+      try setting the page type to Unbounded to get a good screenshot and
+      then set it back to Bounded before saving the level.
+* In the editor, a new Level->Take Screenshot menu item is available which
+  will save just your editor viewport as a PNG image to your screenshots
+  folder.
+* In the editor, the Level->Giant Screenshot feature has been improved.
+    * It now will show a confirmation modal, warning that it may take a
+      while to screenshot a very large level.
+    * While the giant screenshot is processing, a progress bar modal will
+      block interaction with the game so that you don't accidentally modify
+      the level while the screenshot is generating.
+
+Some minor changes:
+
+* Tweaked the player movement physics and adjusted doodads accordingly.
+    * The player is given a lower gravity while they are jumping into the air
+      than the standard (faster) gravity when they are falling. This results
+      in a smoother jump animation instead of the player launching quickly from
+      the ground in order to overcome the constant (fast) gravity.
+    * Coyote time where the player can still jump a few frames late when they
+      walk off a cliff and jump late.
+* Sound effects are now preferred to be in OGG format over MP3 as it is more
+  reliable to compile the game cross-platform without the dependency on mpg123.
+* The game window maximizes on startup to fill the screen.
+
 ## v0.13.2 (Dec 2 2023)
 
 This release brings some new features and optimization for the game's file

pkg/balance/numbers.go

@@ -31,7 +31,7 @@ var (
 		Y: 60,
 	}
 
-	// Player speeds
+	// Player speeds, gravity and movement physics.
 	PlayerMaxVelocity       float64 = 7
 	PlayerJumpVelocity      float64 = -15
 	PlayerAcceleration      float64 = 0.04 // 0.12
@@ -44,6 +44,7 @@ var (
 	SwimGravity             float64 = 3
 	SwimJumpVelocity        float64 = -12
 	SwimJumpCooldown        uint64  = 24 // number of frames of cooldown between swim-jumps
+	CoyoteFrames            uint64  = 4  // Coyote time, frames after we walk off a cliff but can still jump late
 	SlopeMaxHeight                  = 8  // max pixel height for player to walk up a slope
 
 	// Number of game ticks to insist the canvas follows the player at the start

pkg/branding/branding.go

@@ -9,7 +9,7 @@ import (
 const (
 	AppName   = "Sketchy Maze"
 	Summary   = "A drawing-based maze game"
-	Version   = "0.13.2"
+	Version   = "0.14.0"
 	Website   = "https://www.sketchymaze.com"
 	Copyright = "2023 Noah Petherbridge"
 	Byline    = "a game by Noah Petherbridge."

pkg/player_physics.go

@@ -62,7 +62,7 @@ func (s *PlayScene) movePlayer(ev *event.State) {
 					s.jumpCooldownUntil = shmem.Tick + balance.SwimJumpCooldown
 					velocity.Y = balance.SwimJumpVelocity
 				}
-			} else if s.Player.Grounded() {
+			} else if s.Player.Grounded() || s.Player.IsCoyoteTime(true) {
 				velocity.Y = balance.PlayerJumpVelocity
 			}
 		} else {

pkg/uix/actor.go

@@ -6,11 +6,13 @@ import (
 	"sort"
 	"sync"
 
+	"git.kirsle.net/SketchyMaze/doodle/pkg/balance"
 	"git.kirsle.net/SketchyMaze/doodle/pkg/collision"
 	"git.kirsle.net/SketchyMaze/doodle/pkg/doodads"
 	"git.kirsle.net/SketchyMaze/doodle/pkg/level"
 	"git.kirsle.net/SketchyMaze/doodle/pkg/log"
 	"git.kirsle.net/SketchyMaze/doodle/pkg/physics"
+	"git.kirsle.net/SketchyMaze/doodle/pkg/shmem"
 	"git.kirsle.net/go/render"
 	"github.com/dop251/goja"
 	"github.com/google/uuid"
@@ -47,9 +49,10 @@ type Actor struct {
 	inventory    map[string]int // item inventory. doodad name -> quantity, 0 for key item.
 
 	// Movement data.
-	position render.Point
-	velocity physics.Vector
-	grounded bool
+	position     render.Point
+	velocity     physics.Vector
+	grounded     bool
+	lostGroundAt uint64 // tick where grounded last became false, for coyote time
 
 	// Animation variables.
 	animations        map[string]*Animation
@@ -205,12 +208,30 @@ func (a *Actor) Grounded() bool {
 
 // SetGrounded sets the actor's grounded value. If true, also sets their Y velocity to zero.
 func (a *Actor) SetGrounded(v bool) {
+	if a.grounded && !v {
+		a.lostGroundAt = shmem.Tick
+	}
+
 	a.grounded = v
 	// if v && a.velocity.Y > 0 {
 	// 	a.velocity.Y = 0
 	// }
 }
 
+// IsCoyoteTime returns whether the actor has only just lost ground, so can still
+// jump a few frames late.
+//
+// Pass a true value to unset, or "consume" the coyote time. The next call will
+// then return that it is not coyote time, even if the lost ground frame is still
+// within the CoyoteFrames threshold.
+func (a *Actor) IsCoyoteTime(reset bool) (result bool) {
+	result = shmem.Tick-a.lostGroundAt <= balance.CoyoteFrames
+	if reset {
+		a.lostGroundAt = 0
+	}
+	return result
+}
+
 // Hide makes the actor invisible.
 func (a *Actor) Hide() {
 	a.hidden = true