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GeokureliGeokureli
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simplify jumping, add variable jumping (#49)
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6 files changed

+153
-57
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6 files changed

+153
-57
lines changed

‎_proofs/movement/jumping.md‎

Lines changed: 7 additions & 24 deletions
Original file line numberDiff line numberDiff line change
@@ -6,34 +6,17 @@ complexity: 2
66
seealso: [Collision, Movement/Velocity, Movement/Acceleration]
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tags: [movement, jumping, game mechanic]
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---
9-
There are many ways to implement a jumping mechanic, but the simplest method is to add negative <var>y</var> {% api flixel.FlxObject.velocity %} temporarily to a {% api flixel.FlxObject %} with positive <var>y</var> {% api flixel.FlxObject.acceleration %}, using some kind of timer to limit the jump time.
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There are many ways to implement a jumping mechanic, but the simplest method is to add negative <var>y</var> {% api flixel.FlxObject.velocity %} temporarily to a {% api flixel.FlxObject %} with positive <var>y</var> {% api flixel.FlxObject.acceleration %}.
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```haxe
13-
FlxG.collide(box, sprite);
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var jumpPressed:Bool = pad.buttonA.pressed;
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if (jumping && !jumpPressed)
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jumping = false;
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// call super.update first, as it sets touching flags to NONE
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super.update(elapsed);
1915
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/*
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* Reset jumpTimer when touching the floor
22-
* Note: This sprite's touching flags are set via FlxG.collide,
23-
* and are reset to false on super.update
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*/
25-
if (sprite.isTouching(DOWN) && !jumping)
26-
jumpTimer = 0;
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if (jumpTimer >= 0 && jumpPressed)
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{
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jumping = true;
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jumpTimer += elapsed;
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}
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else
34-
jumpTimer = -1;
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// If sprite is resting on box it will set its touching to DOWN
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FlxG.collide(box, sprite);
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36-
// hold button to jump higher (up to 0.25s)
37-
if (jumpTimer > 0 && jumpTimer < 0.25)
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// jump if touching the box, and jump is pressed
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if (sprite.isTouching(DOWN) && !pad.buttonA.pressed)
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sprite.velocity.y = -300;
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```

‎_proofs/movement/variable-jumping.md‎

Lines changed: 39 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,39 @@
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---
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title: Variable Jumping
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concept: Movement
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order: 5
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complexity: 2
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seealso: [Collision, Movement/Velocity, Movement/Jumping]
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tags: [movement, jumping, game mechanic]
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---
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A more advanced jumping technique is to allow the object to jump higher if the button held, there's multiple ways to achieve this, but one common way it maintain the jump velocity for a brief time, so long as the button is held.
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```haxe
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// call super.update first, as it sets touching flags to NONE
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super.update(elapsed);
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// If sprite is resting on box it will set its touching to DOWN
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FlxG.collide(box, sprite);
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18+
// Reset jumpTimer when touching the floor and jump is pressed
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if (sprite.isTouching(DOWN) && pad.buttonA.justPressed)
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{
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jumpTimer = 0;
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}
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// hold button to jump higher (up to 0.25s)
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if (pad.buttonA.pressed)
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{
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jumpTimer += elapsed;
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if (jumpTimer < 0.25)
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{
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sprite.velocity.y = -300;
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}
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}
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else
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{
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// stop jumping after they release
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jumpTimer = 0.25;
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}
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```

‎demos/movement/jumping/source/PlayState.hx‎

Lines changed: 3 additions & 33 deletions
Original file line numberDiff line numberDiff line change
@@ -11,9 +11,6 @@ class PlayState extends FlxState
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var box:FlxSprite;
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var pad:FlxVirtualPad;
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14-
var jumpTimer:Float = 0;
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var jumping:Bool = false;
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override function create()
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{
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super.create();
@@ -36,41 +33,14 @@ class PlayState extends FlxState
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override function update(elapsed:Float)
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{
39-
// call super.update first, because it will set touching flags to NONE
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// call super.update first, as it sets touching flags to NONE
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super.update(elapsed);
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// If sprite is resting on box it will set its touching to DOWN
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FlxG.collide(box, sprite);
4441

45-
var jumpPressed:Bool = pad.buttonA.pressed;
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if (jumping && !jumpPressed)
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{
49-
jumping = false;
50-
}
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/*
53-
* Reset jumpTimer when touching the floor
54-
* Note: This sprite's touching flags are set via FlxG.collide,
55-
* and are reset to false on super.update
56-
*/
57-
if (sprite.isTouching(DOWN) && !jumping)
58-
{
59-
jumpTimer = 0;
60-
}
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62-
if (jumpTimer >= 0 && jumpPressed)
63-
{
64-
jumping = true;
65-
jumpTimer += elapsed;
66-
}
67-
else
68-
{
69-
jumpTimer = -1;
70-
}
71-
72-
// hold button to jump higher (up to 0.25s)
73-
if (jumpTimer > 0 && jumpTimer < 0.25)
42+
// jump if touching the box, and jump is pressed
43+
if (sprite.isTouching(DOWN) && pad.buttonA.justPressed)
7444
{
7545
sprite.velocity.y = -300;
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}

‎demos/movement/variable-jumping/Project.xml‎

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<?xml version="1.0" encoding="utf-8"?>
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<project xmlns="http://lime.software/project/1.0.2"
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xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://lime.software/project/1.0.2 http://lime.software/xsd/project-1.0.2.xsd">
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<app title="variable-jumping" file="variable-jumping" main="Main" version="0.0.1" company="HaxeFlixel" />
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<set name="SWF_VERSION" value="11.8" />
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<window width="320" height="240" fps="60" hardware="true" vsync="false" />
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<window if="desktop" orientation="landscape" fullscreen="false" resizable="true" />
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<window if="mobile" orientation="landscape" fullscreen="true" width="0" height="0" />
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<window background="null" if="html5" />
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<set name="BUILD_DIR" value="export" />
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<source path="source" />
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<source path="../../shared/" />
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<assets path="../../demo-assets" rename="assets" />
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<haxelib name="flixel"/>
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<!--haxelib name="flixel-addons" /-->
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<!--haxelib name="flixel-ui" /-->
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<haxedef name="FLX_NO_TOUCH" unless="mobile" />
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<haxedef name="FLX_NO_GAMEPAD" />
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<haxedef name="FLX_NO_FOCUS_LOST_SCREEN" />
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<haxedef name="FLX_NO_DEBUG" unless="debug" />
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</project>

‎demos/movement/variable-jumping/source/Main.hx‎

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package;
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3+
import flixel.FlxSnippet;
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import openfl.display.Sprite;
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class Main extends Sprite
7+
{
8+
public function new()
9+
{
10+
super();
11+
addChild(new FlxSnippet(0, 0, PlayState));
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}
13+
}

‎demos/movement/variable-jumping/source/PlayState.hx‎

Lines changed: 69 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,69 @@
1+
package;
2+
3+
import flixel.FlxG;
4+
import flixel.FlxSprite;
5+
import flixel.FlxState;
6+
import flixel.ui.FlxVirtualPad;
7+
8+
class PlayState extends FlxState
9+
{
10+
static inline var JUMP_TIME = 0.25;
11+
12+
var sprite:FlxSprite;
13+
var box:FlxSprite;
14+
15+
var pad:FlxVirtualPad;
16+
17+
var jumpTimer:Float = 0;
18+
19+
override function create()
20+
{
21+
super.create();
22+
23+
box = new FlxSprite("assets/bigbox.png");
24+
box.screenCenter(X);
25+
box.y = FlxG.height * 0.75 - box.height / 2;
26+
box.immovable = true;
27+
add(box);
28+
29+
sprite = new FlxSprite("assets/sprite.png");
30+
sprite.screenCenter(X);
31+
sprite.acceleration.y = 900;
32+
sprite.maxVelocity.y = 300;
33+
add(sprite);
34+
35+
pad = new FlxVirtualPad(FlxDPadMode.NONE, FlxActionMode.A);
36+
add(pad);
37+
}
38+
39+
override function update(elapsed:Float)
40+
{
41+
// call super.update first, as it sets touching flags to NONE
42+
super.update(elapsed);
43+
44+
// If sprite is resting on box it will set its touching to DOWN
45+
FlxG.collide(box, sprite);
46+
47+
// Reset jumpTimer when touching the floor and jump is pressed
48+
if (sprite.isTouching(DOWN) && pad.buttonA.justPressed)
49+
{
50+
jumpTimer = 0;
51+
}
52+
53+
// hold button to jump higher (up to 0.25s)
54+
if (pad.buttonA.pressed)
55+
{
56+
jumpTimer += elapsed;
57+
58+
if (jumpTimer < JUMP_TIME)
59+
{
60+
sprite.velocity.y = -300;
61+
}
62+
}
63+
else
64+
{
65+
// stop jumping after they release
66+
jumpTimer = JUMP_TIME;
67+
}
68+
}
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}

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