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Jaggies - a tiny vector graphics library

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Jaggies is a tiny C library for drawing filled polygons and lines using only integer math, static allocations and the standard C library.

This makes Jaggies well suited for running on micro controllers with limited memory.

Jaggies uses a global state, which is built up by adding polygons and lines.

The global state is then rendered in one continuous flow, one pixel at a time, row by row. Polygons are renderer back to front, where latest added polygons will overdraw earlier. Lines are always drawn on top.

This makes it possible to draw basic vector graphics to destinations without random access frame buffer access. No frame buffer is used internally either, keeping memory requirements low.

Jaggies is distributed under the MIT license.

Getting started

Basic example:

void setPixel(void* context, unsigned char color) {
    SomeBitmap* bmp = (SomeBitmap*) context;
    // implementation here!
}

SomeBitmap *bmp = createBitmapSomehow();

// Clear the global state
jaggieClear();

// A square
jaggiePoint square[] = {
    {4, 1},

    {10, 10},
    {100, 10},
    {100, 100},
    {10, 100}
};

// Add a polygon
jaggiePoly(square);

// Render using `setPixel` above
jaggieRender(150, 150, 0, setPixel, bmp);

The full five function API is documented in jaggies.h.

Check out the example in the test folder.

Animated demo

NOTE: The example uses the awesome tigr library, which is included as a submodule, but Jaggies itself has no external dependencies.

Memory requirement and other tweaks

Since required structures are statically allocated, the overall memory requirement is defined by the coordinate type and the maximum number of lines and polygons in the global render state.

These are set to relatively low levels (short int coordinates, 16 polygons and 48 lines) by default, and can be overridden by setting the JAGGIE_INT, JAGGIE_MAX_POLYS and JAGGIE_MAX_LINES preprocessor defines.

The pixel type is unsigned char by default, but can be changed by setting the JAGGIE_COLOR define.

If you are really low on memory and cycles, multi-color support can be turned off by setting the JAGGIE_SINGLE_COLOR define. This causes all primitives to be drawn in the same color, using the last value set by jaggieColor().

Known issues

  • Jaggies is designed for limited memory situations, it is not your fastest pixel pushing friend. But that's OK.

  • Jaggies uses a global state which makes drawing several scenes at the same time impossible. Also fine.