Graphics API

Paint a single pixel in the current colour

Horizontal line running right from (x, y)

Note — This is the fastest primitive there is — it writes whole framebuffer bytes at a time. Building a fill out of hlines beats building it out of pixels by a wide margin.

Vertical line running down from (x, y)

Axis-aligned line in one of four directions

Note — `dir` 0 and 1 are gfx_draw_hline() / gfx_draw_vline() exactly; 2 and 3 are the same lines drawn backwards from (x, y). Call the hline/vline pair directly unless the direction is a runtime value.

Line between two arbitrary points (Bresenham)

Line with a thickness, drawn as a stack of parallel lines

Quadratic Bezier curve through 16 straight segments

Rectangle outline

Rectangle outline with rounded corners

Solid rectangle

Note — Filling with colour 0 is how you erase a region before redrawing it.

Solid rectangle with rounded corners

Rectangle filled with a dither pattern instead of solid colour

Dithered horizontal line

Dithered vertical line

Dithered filled circle

Dithered rounded rectangle

Rectangle with a vertical dither gradient

Note — Equal top and bottom shades give a flat fill, so this doubles as gfx_fill_rect_dithered() when you are animating a gradient in and out.

Rectangle with a horizontal dither gradient

Circle outline, whole or by quadrant

Note — GFX_DRAW_ALL draws full circle and matches GFX_DRAW_UPPER_LEFT | GFX_DRAW_UPPER_RIGHT | GFX_DRAW_LOWER_RIGHT | GFX_DRAW_LOWER_LEFT

Filled circle, whole or by quadrant

Note — GFX_DRAW_ALL draws full circle and matches GFX_DRAW_UPPER_LEFT | GFX_DRAW_UPPER_RIGHT | GFX_DRAW_LOWER_RIGHT | GFX_DRAW_LOWER_LEFT

Circle outline drawn as a dotted ring

Note — GFX_DRAW_ALL draws full circle and matches GFX_DRAW_UPPER_LEFT | GFX_DRAW_UPPER_RIGHT | GFX_DRAW_LOWER_RIGHT | GFX_DRAW_LOWER_LEFT

Select what subsequent draw calls do to the pixels they touch

Note — Sticky — it survives into the next frame. See gfx_color.

Draw a string in the current font and colour

Returns — Width drawn, in pixels — add it to x to continue on the same line

printf-style gfx_draw_str()

Returns — Width drawn, in pixels

Note — `%f` costs far more than the integer conversions. For a value you redraw every frame, scale to an int yourself: `gfx_draw_strf(gfx, x, y, "%d%%", (int)(v * 100))`.

Warning — The formatted result is built in a shared 128-byte buffer and truncated to fit. Do not call it from an audio or timer callback while the UI thread may also be drawing.

Draw one glyph by character code

Returns — Advance width of that glyph in pixels

Select the font for subsequent text calls

Note — Sticky, like the colour. Setting a font is cheap; measuring text is not, so hoist gfx_get_str_width() out of loops rather than the gfx_set_font() call.

Measure a string in the current font without drawing it

Returns — Width in pixels

// centre a label
const gfx_uint_t w = gfx_get_str_width(gfx, label);
gfx_draw_str(gfx, SCREEN_CENTER_X - (w >> 1), 120, label);

Blit a 1-bit XBM bitmap

Note — The blit is opaque — 0 bits are painted in the opposite colour, so the bitmap's bounding box is fully overwritten. Prefer ui_draw_img(), which takes a gfx_img_t from the asset pipeline and knows its own dimensions.

Blit a bitmap rotated about its own centre

Note — Per-pixel and transparent, unlike gfx_draw_xbm(): only set bits are painted, and corners can spill outside the original w x h box.

Warning — This variant reads the bitmap MSB first — the opposite of gfx_draw_xbm() and gfx_draw_xbm_scaled(). Asset-pipeline bitmaps come out mirrored within each byte, so check on device before you build a UI on it.

Blit a bitmap shrunk by an integer factor

Warning — `scale` shrinks, it does not magnify — there is no scale-up entry point in the TAPP API. Sampling is nearest-neighbour, so thin 1px features can vanish entirely.

Restrict drawing to a rectangular window

gfx_set_clip(gfx, 10, 40, 390, 200);   // scrolling list body
draw_rows(gfx, m);
gfx_clip_reset(gfx);

Note — Corner-to-corner, not x/y/w/h. The window is sticky and applies to every primitive, so a forgotten clip makes the rest of your UI silently disappear — always pair it with gfx_clip_reset().

Drop the clip window and draw to the whole screen again

Get the current frame counter (for animations)

Returns — Frame counter value, incremented on each display refresh

Note — This is the clock to drive animation from — a tapp has no wall time. Divide it down for slower motion: `ui_draw_anim(gfx, x, y, ui_get_frame(gfx) >> 2, &my_anim)`.

Default UI body font

Headings / emphasis

Monospace — counters, numeric readouts