Renders notes, receptors, and chart elements
[heading: "Description"]Handles all visual rendering of the chart during gameplay, including notes, receptors, hold/roll bodies, mines, beat lines, and speed/background change indicators. Supports both falling and rising scroll directions with configurable speed modifiers. Manages sprite pooling and z-ordering for efficient rendering performance.
[heading: "Key Features"] [list] * Falling and rising scroll direction rendering * Hold and roll note body rendering * Mine note animation and display * Beat line, speed change, and background change overlays * Object pooling for sprite reuse [/list] [heading: "Constructor"] [table header] [ Parameter | Type | Description ] [ scene | Phaser.Scene | The Phaser game scene ] [ song | Object | Song data containing chart and metadata ] [ difficultyIndex | number | Index into the chart's difficulty array ] [ options | Object | Rendering and gameplay configuration options ] [/table] [heading: "Properties"] [table header] [ Property | Type | Description ] [ scrollDirection | string | Scroll direction: "falling" or "rising" ] [ VERTICAL_SEPARATION | number | Vertical pixel spacing between note rows ] [ NOTE_SPEED_MULTIPLIER | number | Base note speed multiplier including screen constant ] [ JUDGE_LINE | number | Y position of the judgement line ] [ DIRECTION | number | Render direction: -1 for falling, 1 for rising ] [ COLUMN_SIZE | number | Width of each note column ] [ COLUMN_SEPARATION | number | Gap between note columns ] [ receptors | Array | Receptor sprites for each of the four columns ] [ difficulty | Object | The selected difficulty from the chart ] [ notes | Array | Note data for the selected difficulty ] [ bpmChanges | Array | BPM change markers from the chart ] [ stops | Array | Stop events from the chart ] [/table] [heading: "Methods"] [table header] [ Method | Parameters | Description ] [ load | (song, difficultyIndex) | Loads a song's chart data for the given difficulty into the renderer. Cleans up any previously pooled note sprites before reloading. ] [ recreate | (song, difficultyIndex, options) | Destroys this renderer and returns a fresh instance for the given chart. Used to rebuild the renderer with different chart data or options. ] [ initialize | () | Sets up receptor sprites, explosion effects, and the chart background. Called once during construction to build the initial visual layout. ] [ calculateVerticalPosition | (note, now, beat) | Computes the on-screen Y position of a note for the current scroll direction. Also returns the past-scroll distance and hold body height for freeze notes. ] [ getCurrentBPM | (beat) | Returns the BPM in effect at the given beat position. ] [ beatToSec | (beat) | Converts a beat position to seconds, accounting for BPM changes and stops. ] [ secToBeat | (sec) | Converts a time in seconds to a beat position, accounting for stops. ] [ render | (now, beat) | Main render entry point called each frame. Dispatches to the falling or rising renderer and draws optional overlay elements. ] [ renderFalling | (now, beat) | Renders all notes in a falling scroll direction with miss checking and z-ordering. Called by render() when the scroll direction is set to "falling". ] [ renderRising | (now, beat) | Renders all notes in a rising scroll direction with miss checking and z-ordering. Called by render() when the scroll direction is set to "rising". ] [ renderMine | (note, x, yPos) | Positions and animates a mine note's sprite at the given coordinates. Reuses pooled sprites or creates new ones on demand. ] [ renderArrow | (note, x, yPos) | Positions an arrow note's sprite, applying its color frame and column rotation. Reuses pooled sprites or creates new ones on demand. ] [ renderHoldNote | (note, x, yPos, bodyHeight, now, beat, direction) | Renders hold and roll note bodies and endpoints with active hold tracking. Handles miss checking, active-state trimming, and tinting for holds. ] [ renderTimeLines | (now, beat) | Renders beat division lines for the visible measures on screen. Cleans up off-screen and stuck timeline sprite objects. ] [ renderSpeedChanges | (now, beat) | Draws BPM change and stop indicator lines with tags on the chart. Redraws the speed-mod overlay graphics each time it is called. ] [ renderBGChanges | (now, beat) | Draws background change indicator lines with tags on the chart. Redraws the background-change overlay graphics each time it is called. ] [ createExplosion | (note, type) | Spawns and animates an explosion effect at the matching receptor position. Uses normal or mine explosion textures depending on the type requested. ] [ toggleHoldExplosion | (column, visible) | Shows or hides the active-hold explosion glow on a receptor. ] [ destroy | () | Destroys all sprite groups and graphics used for rendering the chart. ] [/table] [heading: "Example Usage (Modding)"] [codeblock javascript] // Creating a ChartRenderer for a song const renderer = new ChartRenderer(scene, songData, 0, { scrollDirection: "falling", speedMod: "X-MOD", noteSpeedMultiplier: 1.5, enableBeatLines: true }); // Render at current time renderer.render(currentTime, currentBeat); [/codeblock] [footer: "© Retora 2026"]