graphics-and-shapes（图形和形状）

Phaser 4 — Graphics and Shapes

Drawing primitives with the Graphics game object, and using Shape game objects (Arc, Curve, Ellipse, Grid, IsoBox, IsoTriangle, Line, Polygon, Rectangle, Star, Triangle).

Related skills: sprites-and-images.md, game-object-components.md

Quick Start

// Draw a filled rectangle and stroked circle with Graphics
const gfx = this.add.graphics();

gfx.fillStyle(0x00aa00, 1);
gfx.fillRect(50, 50, 200, 100);

gfx.lineStyle(3, 0xff0000, 1);
gfx.strokeCircle(400, 150, 60);

// Same shapes as standalone Shape game objects
const rect = this.add.rectangle(150, 100, 200, 100, 0x00aa00);
const circle = this.add.circle(400, 150, 60);
circle.setStrokeStyle(3, 0xff0000);

Core Concepts — Graphics vs Shape Objects

Phaser offers two approaches for rendering primitives without textures.

Graphics Game Object

Created with this.add.graphics(). An imperative drawing surface — you call methods like fillRect, strokeCircle, beginPath/lineTo/strokePath to build up a command buffer that replays each frame.

• Factory: this.add.graphics(config?) where config is {x?, y?, lineStyle?, fillStyle?}.
• Supports paths, arcs, gradients, rounded rectangles, canvas transforms (translateCanvas, scaleCanvas, rotateCanvas), and save/restore.
• Can generate a Texture from the drawing via generateTexture(key, width, height).
• Expensive to render, especially with complex shapes. Uses its own WebGL shader. Group Graphics objects together to minimize batch flushes.
• Components: AlphaSingle, BlendMode, Depth, Lighting, Mask, RenderNodes, Transform, Visible, ScrollFactor.
• Does NOT include Origin or GetBounds (position is set via options or setPosition).

Shape Game Objects

Individual game objects (Arc, Rectangle, Star, etc.) extending the base Shape class. Each renders one predefined geometric shape with precomputed path data.

• Created via dedicated factory methods: this.add.rectangle(...), this.add.circle(...), etc.
• Fully featured game objects: can be tweened, scaled, added to groups/containers, enabled for input/physics.
• Style via setFillStyle(color, alpha) and setStrokeStyle(lineWidth, color, alpha).
• Share the same WebGL batch as Graphics for efficient rendering.
• Do NOT support gradients, path detail threshold, or canvas transforms.
• Components: AlphaSingle, BlendMode, Depth, GetBounds, Lighting, Mask, Origin, RenderNodes, ScrollFactor, Transform, Visible.
• Include Origin and GetBounds (unlike Graphics).

When to use which:

• Use Graphics for dynamic drawing, complex paths, multiple shapes on one object, gradients, or generating textures.
• Use Shape objects for individual UI elements, simple indicators, physics-enabled shapes, or anything that benefits from game object features (origin, bounds, input).

Common Patterns

Fill and Stroke Styles (Graphics)

const gfx = this.add.graphics();

// Solid fill — call before any fill* method
gfx.fillStyle(0xff0000, 1);          // (color, alpha)

// Line style — call before any stroke* method
gfx.lineStyle(4, 0x00ff00, 1);       // (width, color, alpha)

// Gradient fill (WebGL only) — 4 corner colors
gfx.fillGradientStyle(
    0xff0000, 0x00ff00, 0x0000ff, 0xffff00,  // tl, tr, bl, br colors
    1, 1, 1, 1                                 // tl, tr, bl, br alphas
);
gfx.fillRect(0, 0, 300, 200);

// Gradient line style (WebGL only)
gfx.lineGradientStyle(2, 0xff0000, 0x00ff00, 0x0000ff, 0xffff00, 1);

Drawing Primitives (Graphics)

const gfx = this.add.graphics();

// Rectangles
gfx.fillStyle(0x0000ff);
gfx.fillRect(x, y, width, height);
gfx.lineStyle(2, 0xffffff);
gfx.strokeRect(x, y, width, height);

// Circles
gfx.fillCircle(x, y, radius);
gfx.strokeCircle(x, y, radius);

// Ellipses
gfx.fillEllipse(x, y, width, height, smoothness);
gfx.strokeEllipse(x, y, width, height, smoothness);   // smoothness defaults to 32

// Triangles
gfx.fillTriangle(x0, y0, x1, y1, x2, y2);
gfx.strokeTriangle(x0, y0, x1, y1, x2, y2);

// Points (draws a small square)
gfx.fillPoint(x, y, size);                             // size defaults to 1

// Lines
gfx.lineBetween(x1, y1, x2, y2);

Rounded Rectangles

const gfx = this.add.graphics();

// Uniform radius (default 20)
gfx.fillStyle(0x333333);
gfx.fillRoundedRect(50, 50, 300, 200, 16);
gfx.lineStyle(2, 0xffffff);
gfx.strokeRoundedRect(50, 50, 300, 200, 16);

// Per-corner radius
gfx.fillRoundedRect(50, 50, 300, 200, {
    tl: 20, tr: 20, bl: 0, br: 0
});

// Concave corners (negative values)
gfx.fillRoundedRect(50, 50, 300, 200, { tl: -10, tr: -10, bl: -10, br: -10 });

Path Drawing

const gfx = this.add.graphics();

// Manual path
gfx.lineStyle(3, 0xffff00);
gfx.beginPath();
gfx.moveTo(100, 100);
gfx.lineTo(200, 50);
gfx.lineTo(300, 100);
gfx.lineTo(250, 200);
gfx.closePath();
gfx.strokePath();       // or gfx.stroke() — alias for strokePath

// Fill a path
gfx.fillStyle(0x00aaff);
gfx.beginPath();
gfx.moveTo(100, 100);
gfx.lineTo(200, 50);
gfx.lineTo(300, 100);
gfx.closePath();
gfx.fillPath();         // or gfx.fill() — alias for fillPath

// Arc within a path (angles in radians)
gfx.beginPath();
gfx.arc(200, 200, 80, 0, Math.PI / 2, false, 0);   // (x, y, radius, startAngle, endAngle, anticlockwise, overshoot)
gfx.strokePath();

// Pie slice
gfx.slice(200, 200, 80, 0, Math.PI / 3, false);     // auto begins/closes path
gfx.fillPath();

// Stroke/fill from point arrays
gfx.strokePoints(points, closeShape, closePath, endIndex);
gfx.fillPoints(points, closeShape, closePath, endIndex);

Geom Shape Helpers

Graphics has convenience methods that accept Phaser.Geom objects directly:

const circle = new Phaser.Geom.Circle(200, 200, 50);
const rect = new Phaser.Geom.Rectangle(50, 50, 100, 80);

gfx.fillCircleShape(circle);
gfx.strokeCircleShape(circle);
gfx.fillRectShape(rect);
gfx.strokeRectShape(rect);
gfx.fillTriangleShape(triangle);
gfx.strokeTriangleShape(triangle);
gfx.strokeLineShape(line);
gfx.fillEllipseShape(ellipse, smoothness);
gfx.strokeEllipseShape(ellipse, smoothness);

Canvas Transforms (Graphics)

const gfx = this.add.graphics();

gfx.save();
gfx.translateCanvas(100, 100);
gfx.rotateCanvas(0.5);           // radians
gfx.scaleCanvas(2, 2);
gfx.fillStyle(0xff0000);
gfx.fillRect(0, 0, 50, 50);     // draws at translated/rotated/scaled position
gfx.restore();

Generating Textures from Graphics

const gfx = this.add.graphics();
gfx.fillStyle(0xff0000);
gfx.fillCircle(32, 32, 32);
gfx.generateTexture('redCircle', 64, 64);
gfx.destroy();

// Now use as a regular texture
this.add.image(400, 300, 'redCircle');

Note: fillGradientStyle will NOT appear in generated textures (Canvas API limitation).

Shape Objects — Fill and Stroke

// Shapes set fill via constructor or setFillStyle
const rect = this.add.rectangle(200, 150, 100, 80, 0xff0000, 1);

// Change fill later
rect.setFillStyle(0x00ff00, 0.8);

// Add stroke (not set by default)
rect.setStrokeStyle(3, 0xffffff, 1);  // (lineWidth, color, alpha)

// Remove fill or stroke
rect.setFillStyle();    // no args = isFilled becomes false
rect.setStrokeStyle();  // no args = isStroked becomes false

// Direct property access
rect.fillColor = 0x0000ff;
rect.fillAlpha = 0.5;
rect.strokeColor = 0xffffff;
rect.strokeAlpha = 1;
rect.lineWidth = 2;
rect.isFilled = true;
rect.isStroked = true;
rect.closePath = true;   // close stroke path (default true)

All Shape Types

API Quick Reference — Graphics Methods

Style Methods

Path Methods

Shape Drawing Methods

Geom Shape Methods

Transform and State Methods

Shape Base Class Methods

Gotchas

1. Graphics arc() uses radians; Shape arc factory uses degrees. The Graphics arc method takes start/end angles in radians. The this.add.arc() factory takes them in degrees (0-360). Mixing these up is the most common bug.
2. Set style BEFORE drawing. fillStyle and lineStyle must be called before the corresponding fill/stroke method. They are not retroactive.
3. Graphics has no Origin or GetBounds. Unlike Shape objects, Graphics does not include the Origin or GetBounds components. Use setPosition(x, y) and displayOriginX/displayOriginY instead.
4. Shape isFilled/isStroked defaults. Shapes created with a fillColor parameter have isFilled = true. But isStroked defaults to false — you must call setStrokeStyle() explicitly.
5. Line shape is stroke-only. The Line shape does not support fill. Its constructor takes strokeColor/strokeAlpha (not fillColor).
6. IsoBox/IsoTriangle are fill-only. These shapes cannot be stroked. Grid supports outline strokes via its constructor parameters (outlineFillColor, outlineFillAlpha).
7. generateTexture uses Canvas API. Gradient fills (fillGradientStyle) will not appear in textures generated with generateTexture. Only Canvas-compatible features are captured.
8. Performance: Graphics is expensive. Each frame the command buffer is replayed and geometry is rebuilt (WebGL decomposes to polygons). For static shapes, call generateTexture and use the resulting texture as a Sprite. Group Graphics objects together to minimize batch breaks.
9. pathDetailThreshold (v4 new). Graphics has a pathDetailThreshold property (default -1, uses config render.pathDetailThreshold). Path segments below this pixel threshold are combined, improving WebGL performance on complex shapes. Evaluated in screen pixels, so detail emerges when zoomed in.
10. Rounded rect radius can be an object or number. Pass {tl, tr, bl, br} for per-corner control. Negative values create concave corners. Default is 20 when omitted.
11. Shape closePath property. The closePath property on Shape objects (default true) controls whether the stroke path is automatically closed. Set to false for open stroked shapes.
12. Shape objects do NOT support tint methods. Unlike Sprites and Images, Shape game objects do not have setTint() or tint properties. Use setFillStyle(color, alpha) and setStrokeStyle(lineWidth, color, alpha) instead.
13. Polygon getBounds() incorrect with negative points. If any polygon points have negative coordinates, getBounds() returns wrong values. Use Phaser.Geom.Polygon.GetAABB(polygon.geom) instead and adjust the returned Rectangle position.

Shape-Specific Methods

Star

const star = this.add.star(400, 300, 5, 32, 64, 0xffff00);

star.setPoints(8);          // change number of points
star.setInnerRadius(20);    // change inner radius
star.setOuterRadius(80);    // change outer radius

Line (Tapering)

const line = this.add.line(400, 300, 0, 0, 200, 100, 0xffffff);

// setLineWidth(startWidth, endWidth) — endWidth is WebGL only (tapering effect)
line.setLineWidth(4, 1);   // tapers from 4px to 1px (Canvas uses startWidth only)

Grid (Alternating Colors, Stroke, Padding)

const grid = this.add.grid(400, 300, 320, 240, 32, 32, 0x222222);

// Alternating cell color (checkerboard)
grid.setAltFillStyle(0x444444, 1);  // no args = disable alternating cells

// Grid uses setStrokeStyle for cell outlines (inherited from Shape)
grid.setStrokeStyle(1, 0x666666, 1);

// v4: control outside edge stroke
grid.strokeOutside = true;             // stroke the outer border
grid.strokeOutsideIncomplete = false;  // skip partial cells on right/bottom edges

// Cell padding (default 0.5) — gutter between cells is 2x this value
grid.cellPadding = 1;

IsoBox / IsoTriangle

const box = this.add.isobox(200, 200, 48, 32, 0xeeeeee, 0x999999, 0xcccccc);

box.setFaces(true, true, false);  // showTop, showLeft, showRight
box.setProjection(4);             // isometric projection value

const tri = this.add.isotriangle(400, 200, 48, 32, false, 0xeeeeee, 0x999999, 0xcccccc);

tri.setReversed(true);            // flip upside down
tri.setFaces(true, true, true);
tri.setProjection(4);

Source File Map