A fantasy cosole with vector graphics, similar to vector arcade games. This is my first attempt to program a game engine and is kept very simple on purpose. If this project works well I might make a more feature rich engine.
It is indented to have a runtime for various systems/consoles. The games are WASM files with maybe some additional information. To interact with the runtime, the game must export some functions (update, maybe draw) and can import functions (getInput, drawShape, etc ).
The console has a square screen (resolution depends on the runtime) with RGB color. It can draw with straight lines with a fixed with and and a specified color. Single player NES-style input (D-Pad, 2 action buttons, 2 menu buttons). It can do simple tones with a fixed frequncy and fixed length.
| function name | function |
|---|---|
| setPosition(f32 x, f32 y) | Sets the pointer/cursor/electron beam to the given position. |
| drawLineTo(f32 x, f32 y) | Draws a line between the current position and the given position. The current position is set to the given position. |
| setColor(i32) | Sets the current color to the given value (RGBA). |
| clear(i32) | Clears the screen with the given color (RGBA). Usually called before any drawing for the current frame is done. |
| translate(f32 x, f32 y) | Translates the screen transform by the given amount. |
| scale(f32 x, f32 y) | Scales the screen transform by the given amount. |
| rotate(f32 angle) | Rotates the screen transform by the given amount (angle is in radiants). |
| setTransform(f32 m_00, f32 m_01, f32 m_10, f32 m_11, f32 m_20, f32 m_21) | Sets the screen transform to the given values. The screen transform is a 3x3 column major matrix. NOTE: In this function only the top two rows can be set. The bottom one is by default (0, 0, 1). |
| push() | Pushes the current screen transform on a stack, so it can be restored later. |
| pop() | Pops the last added transform from the stack and sets it as the current screen transform |
| setWrapMode(i32 mode) | Sets the wrap mode of the screen. (0: none, 1: horizontal, 2: vertical, 3: horizontal and vertical). No wraping is the default. |
| getInput() | Gets the input as an i32 where each bit represents if a button is pressed or not. A is represented by the least significant bit and the other buttons in the following order B START SELECT UP DOWN LEFT RIGHT |
| playTone(f32 frequency, f32 duration) | Plays a tone withe the given frequency for the given duration (in ms). |
| function name | function |
|---|---|
| init() | This function is called once at the beginning. (before the first call of update) |
| update() | This function is called 60 times per second by the runtime. |
The normal input methode should be gamepad with it's buttons map to something as close as possible to a NES pad. For convenience there is also keyboard input:
| keyboard key | button |
|---|---|
| W or ArrowUp | up |
| S or ArrowDown | down |
| A or ArrowLeft | left |
| D or ArrowRight | right |
| J | A |
| K | B |
| U | start |
| I | select |