wasm4-gr

This module provides Grain bindings to WASM-4, a low-level fantasy game console for building small games with WebAssembly. For a general overview of WASM-4, check our their docs at https://wasm4.org/docs/.

Values

Functions and constants included in the Wasm4 module.

Wasm4._SCREEN_SIZE

_SCREEN_SIZE : Uint8

Wasm4._BUTTON_1

_BUTTON_1 : Uint8

Wasm4._BUTTON_2

_BUTTON_2 : Uint8

Wasm4._BUTTON_LEFT

_BUTTON_LEFT : Uint8

Wasm4._BUTTON_RIGHT

_BUTTON_RIGHT : Uint8

Wasm4._BUTTON_UP

_BUTTON_UP : Uint8

Wasm4._BUTTON_DOWN

_BUTTON_DOWN : Uint8

Wasm4._MOUSE_LEFT

_MOUSE_LEFT : Uint16

Wasm4._MOUSE_RIGHT

_MOUSE_RIGHT : Uint16

Wasm4._MOUSE_MIDDLE

_MOUSE_MIDDLE : Uint16

Wasm4._SYSTEM_PRESERVE_FRAMEBUFFER

_SYSTEM_PRESERVE_FRAMEBUFFER : Uint8

Wasm4._SYSTEM_HIDE_GAMEPAD_OVERLAY

_SYSTEM_HIDE_GAMEPAD_OVERLAY : Uint8

Wasm4._BLIT_1BPP

_BLIT_1BPP : Uint8

Wasm4._BLIT_2BPP

_BLIT_2BPP : Uint8

Wasm4._BLIT_FLIP_X

_BLIT_FLIP_X : Uint8

Wasm4._BLIT_FLIP_Y

_BLIT_FLIP_Y : Uint8

Wasm4._BLIT_ROTATE

_BLIT_ROTATE : Uint8

Wasm4._TONE_PULSE1

_TONE_PULSE1 : Uint8

Wasm4._TONE_PULSE2

_TONE_PULSE2 : Uint8

Wasm4._TONE_TRIANGLE

_TONE_TRIANGLE : Uint8

Wasm4._TONE_NOISE

_TONE_NOISE : Uint8

Wasm4._TONE_MODE1

_TONE_MODE1 : Uint8

Wasm4._TONE_MODE2

_TONE_MODE2 : Uint8

Wasm4._TONE_MODE3

_TONE_MODE3 : Uint8

Wasm4._TONE_MODE4

_TONE_MODE4 : Uint8

Wasm4.gamepad1

gamepad1 : () => Uint8

Gets the values of the first gamepad.

Examples:

Wasm4.gamepad1() & Wasm4._BUTTON_LEFT

Wasm4.gamepad2

gamepad2 : () => Uint8

Gets the values of the second gamepad.

Examples:

Wasm4.gamepad2() & Wasm4._BUTTON_LEFT

Wasm4.gamepad3

gamepad3 : () => Uint8

Gets the values of the third gamepad.

Examples:

Wasm4.gamepad3() & Wasm4._BUTTON_LEFT

Wasm4.gamepad4

gamepad4 : () => Uint8

Gets the values of the fourth gamepad.

Examples:

Wasm4.gamepad4() & Wasm4._BUTTON_LEFT

Wasm4.mouseButtons

mouseButtons : () => Uint8

Gets the values of the mouse buttons.

Examples:

Wasm4.mouseButtons() & Wasm4._MOUSE_LEFT

Wasm4.drawColors

drawColors : (colors: Uint16) => Void

Set the draw colors. The draw colors are a set of 4 indexes into the palette. Drawing functions use these indexes to decide which colors to use, and what to use them for.

It’s a 16 bit value that holds 4 indexes. Bits 0-3 (the least significant bits) hold the first draw color, bits 4-7 hold the second draw color, and so on.

Setting a draw color to 1 means use the palette color 1 for that draw color. The same applies when setting a draw color to 2, 3, or 4.

For example, rect() uses the first draw color for the fill color, and the second draw color as the outline color.

Wasm4.setPalette

setPalette :
  (color1: Uint32, color2: Uint32, color3: Uint32, color4: Uint32) => Void

Set the color palette.

Wasm4.blit

blit :
  (sprite: Bytes, x: Uint8, y: Uint8, width: Uint8, height: Uint8,
   flags: Uint8) => Void

Copies pixels to the framebuffer.

Parameters:

param	type	description
`sprite`	`Bytes`	The raw pixel data stored in either 1BPP or 2BPP format.
`x`	`Uint8`	X position in the destination framebuffer.
`y`	`Uint8`	Y position in the destination framebuffer.
`width`	`Uint8`	Width of the sprite.
`height`	`Uint8`	Height of the sprite.
`flags`	`Uint8`	Flags that modify behavior: _BLIT_2BPP, _BLIT_FLIP_X, _BLIT_FLIP_Y, _BLIT_ROTATE

Wasm4.blitSub

blitSub :
  (sprite: Bytes, x: Uint8, y: Uint8, width: Uint8, height: Uint8,
   srcX: Uint16, srcY: Uint16, stride: Uint8, flags: Uint8) => Void

Copies a subregion within a larger sprite atlas to the framebuffer. Same as blit, but with 3 additional parameters.

Parameters:

param	type	description
`sprite`	`Bytes`	The raw pixel data stored in either 1BPP or 2BPP format.
`x`	`Uint8`	X position in the destination framebuffer.
`y`	`Uint8`	Y position in the destination framebuffer.
`width`	`Uint8`	Width of the sprite.
`height`	`Uint8`	Height of the sprite.
`srcX`	`Uint16`	Source X position of the sprite region.
`srcY`	`Uint16`	Source Y position of the sprite region.
`stride`	`Uint8`	Total width of the overall sprite atlas. This is typically larger than width.
`flags`	`Uint8`	Flags that modify behavior: _BLIT_2BPP, _BLIT_FLIP_X, _BLIT_FLIP_Y, _BLIT_ROTATE

Wasm4.line

line : (x1: Uint8, y1: Uint8, x2: Uint8, y2: Uint8) => Void

Draws a line between two points.

Wasm4.hline

hline : (x: Uint8, y: Uint8, len: Uint8) => Void

Draws a horizontal line between (x, y) and (x + len - 1, y).

Wasm4.vline

vline : (x: Uint8, y: Uint8, len: Uint8) => Void

Draws a vertical line between (x, y) and (x, y + len - 1).

Wasm4.oval

oval : (x: Uint8, y: Uint8, width: Uint8, height: Uint8) => Void

Draws an oval (or circle).

Wasm4.rect

rect : (x: Uint8, y: Uint8, width: Uint8, height: Uint8) => Void

Draws a rectangle.

Wasm4.text

text : (string: String, x: Uint8, y: Uint8) => Void

Draws text using the built-in system font. The string may contain new-line (\n) characters.

Wasm4.tone

tone :
  (frequency: Uint16, ?slideFrequency: Uint16, duration: Uint16,
   volume: Uint8, flags: Uint8) => Void

Plays a sound tone. The high bits of frequency can optionally describe a pitch slide effect.

Parameters:

param	type	description
`frequency`	`Uint16`	Wave frequency in hertz.
`?slideFrequency`	`Uint16`	Wave frequency in hertz to slide up to.
`duration`	`Uint16`	Duration of the tone in frames (1/60th of a second), up to 255 frames.
`volume`	`Uint8`	Volume of the sustain and attack durations, between 0 and 100.
`flags`	`Uint8`	Flags that modify behavior.

Wasm4.diskr

diskr : (size: Uint16) => Bytes

Reads up to size bytes from persistent storage.

Returns:

type	description
`Bytes`	the number of bytes read, which may be less than size.

Wasm4.diskw

diskw : (bytes: Bytes) => Uint16

Writes up to size bytes into persistent storage.

Any previously saved data on the disk is replaced.

Returns:

type	description
`Uint16`	the number of bytes written, which may be less than size.

Wasm4.trace

trace : (msg: String) => Void

Prints a message to the debug console.