akgl_text_rendertextat() called renderer->draw_texture() with no check on
the global renderer, its sdl_renderer or the function pointer itself, so a
backend that has an SDL_Renderer but was never bound segfaults on the first
line of text -- the state akgl_render_bind2d() exists to get a host out of.
All three are now checked, with AKERR_NULLPOINTER as the draw entry points
report, and checked before anything is rasterized rather than after.
tests/text.c grows a software renderer with a bound backend and covers all
three refusals plus the successful draw, wrapped and unwrapped: src/text.c
goes from 58% to 100% line coverage. A made-up SDL_Renderer pointer is not
enough to test this -- SDL refuses the bogus handle on its own and the call
fails for the wrong reason, which a deleted check survives.
Also documents what the tests found: SDL_ttf refuses the empty string, so
drawing an empty line is an error while measuring one is not. Filed in
TODO.md rather than pinned in the suite.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
akbasic needs the advance width of one character cell to build a terminal-style
text surface, and the wrapped size to know where a string crosses the right
margin. akgl_text_measure and akgl_text_measure_wrapped report both over
TTF_GetStringSize and TTF_GetStringSizeWrapped; neither needs a renderer, so
this half of the text subsystem is testable without the offscreen harness.
A negative wrap length is refused with AKERR_OUTOFBOUNDS: SDL_ttf reads it as a
very large unsigned width and quietly stops wrapping, which would return a
measurement that is wrong rather than an error the caller can see.
Also fixes akgl_text_loadfont, which checked name twice and passed an unchecked
filepath to TTF_OpenFont (TODO item 39).
The fixture font is a 10 KB monospaced ASCII subset of Liberation Mono, renamed
because "Liberation" is a Reserved Font Name; see
tests/assets/akgl_test_mono.LICENSE.txt. Monospaced so the suite can assert
width("AAAA") == 4 * width("A") rather than hardcode glyph metrics.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
