--- title: Wasm4 --- 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** ```grain _SCREEN_SIZE : Uint8 ``` ### Wasm4.**_FONT_SIZE** ```grain _FONT_SIZE : Uint8 ``` ### Wasm4.**_BUTTON_1** ```grain _BUTTON_1 : Uint8 ``` ### Wasm4.**_BUTTON_2** ```grain _BUTTON_2 : Uint8 ``` ### Wasm4.**_BUTTON_LEFT** ```grain _BUTTON_LEFT : Uint8 ``` ### Wasm4.**_BUTTON_RIGHT** ```grain _BUTTON_RIGHT : Uint8 ``` ### Wasm4.**_BUTTON_UP** ```grain _BUTTON_UP : Uint8 ``` ### Wasm4.**_BUTTON_DOWN** ```grain _BUTTON_DOWN : Uint8 ``` ### Wasm4.**_MOUSE_LEFT** ```grain _MOUSE_LEFT : Uint16 ``` ### Wasm4.**_MOUSE_RIGHT** ```grain _MOUSE_RIGHT : Uint16 ``` ### Wasm4.**_MOUSE_MIDDLE** ```grain _MOUSE_MIDDLE : Uint16 ``` ### Wasm4.**_SYSTEM_PRESERVE_FRAMEBUFFER** ```grain _SYSTEM_PRESERVE_FRAMEBUFFER : Uint8 ``` ### Wasm4.**_SYSTEM_HIDE_GAMEPAD_OVERLAY** ```grain _SYSTEM_HIDE_GAMEPAD_OVERLAY : Uint8 ``` ### Wasm4.**_BLIT_1BPP** ```grain _BLIT_1BPP : Uint8 ``` ### Wasm4.**_BLIT_2BPP** ```grain _BLIT_2BPP : Uint8 ``` ### Wasm4.**_BLIT_FLIP_X** ```grain _BLIT_FLIP_X : Uint8 ``` ### Wasm4.**_BLIT_FLIP_Y** ```grain _BLIT_FLIP_Y : Uint8 ``` ### Wasm4.**_BLIT_ROTATE** ```grain _BLIT_ROTATE : Uint8 ``` ### Wasm4.**_TONE_PULSE1** ```grain _TONE_PULSE1 : Uint8 ``` ### Wasm4.**_TONE_PULSE2** ```grain _TONE_PULSE2 : Uint8 ``` ### Wasm4.**_TONE_TRIANGLE** ```grain _TONE_TRIANGLE : Uint8 ``` ### Wasm4.**_TONE_NOISE** ```grain _TONE_NOISE : Uint8 ``` ### Wasm4.**_TONE_MODE1** ```grain _TONE_MODE1 : Uint8 ``` ### Wasm4.**_TONE_MODE2** ```grain _TONE_MODE2 : Uint8 ``` ### Wasm4.**_TONE_MODE3** ```grain _TONE_MODE3 : Uint8 ``` ### Wasm4.**_TONE_MODE4** ```grain _TONE_MODE4 : Uint8 ``` ### Wasm4.**gamepad1** ```grain gamepad1 : () => Uint8 ``` Gets the values of the first gamepad. Examples: ```grain Wasm4.gamepad1() & Wasm4._BUTTON_LEFT ``` ### Wasm4.**gamepad2** ```grain gamepad2 : () => Uint8 ``` Gets the values of the second gamepad. Examples: ```grain Wasm4.gamepad2() & Wasm4._BUTTON_LEFT ``` ### Wasm4.**gamepad3** ```grain gamepad3 : () => Uint8 ``` Gets the values of the third gamepad. Examples: ```grain Wasm4.gamepad3() & Wasm4._BUTTON_LEFT ``` ### Wasm4.**gamepad4** ```grain gamepad4 : () => Uint8 ``` Gets the values of the fourth gamepad. Examples: ```grain Wasm4.gamepad4() & Wasm4._BUTTON_LEFT ``` ### Wasm4.**mouseButtons** ```grain mouseButtons : () => Uint8 ``` Gets the values of the mouse buttons. Examples: ```grain Wasm4.mouseButtons() & Wasm4._MOUSE_LEFT ``` ### Wasm4.**drawColors** ```grain 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** ```grain setPalette : (color1: Uint32, color2: Uint32, color3: Uint32, color4: Uint32) => Void ``` Set the color palette. ### Wasm4.**blit** ```grain 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** ```grain 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** ```grain line : (x1: Uint8, y1: Uint8, x2: Uint8, y2: Uint8) => Void ``` Draws a line between two points. ### Wasm4.**hline** ```grain hline : (x: Uint8, y: Uint8, len: Uint8) => Void ``` Draws a horizontal line between (x, y) and (x + len - 1, y). ### Wasm4.**vline** ```grain vline : (x: Uint8, y: Uint8, len: Uint8) => Void ``` Draws a vertical line between (x, y) and (x, y + len - 1). ### Wasm4.**oval** ```grain oval : (x: Uint8, y: Uint8, width: Uint8, height: Uint8) => Void ``` Draws an oval (or circle). ### Wasm4.**rect** ```grain rect : (x: Uint8, y: Uint8, width: Uint8, height: Uint8) => Void ``` Draws a rectangle. ### Wasm4.**text** ```grain 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** ```grain 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** ```grain 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** ```grain 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** ```grain trace : (msg: String) => Void ``` Prints a message to the debug console.