The graphics verbs documented a coordinate transform that did not exist. With
SCALE off a coordinate went straight to akgl_draw_* as a pixel address, so an
800x600 window drew a C128 listing into its corner and left the rest unused --
while the chapter said coordinates were 320x200 and stretching to fit was the
host's business.
akbasic_GraphicsBackend gains a size entry point, require_graphics() asks it
before every verb that draws so a resized window is honoured between two
statements, and 320x200 becomes the fallback for a backend that leaves it NULL.
It is the record's one optional member, so a host written against the old header
keeps the behaviour it had.
SCALE now maps onto the device, and RGR(1)/RGR(2) report the drawing surface so
a program can use a window whose size it did not choose. RGR(0) is BASIC 7.0's
own field, the GRAPHIC mode.
SCALE also mapped xmax onto the width rather than onto the last pixel, so
SCALE 1, 319, 199 followed by DRAW 1, 319, 199 drew nothing at all -- one pixel
past the surface. Fixed in the same line, because it is what makes "SCALE gives
a C128 listing the whole window" true rather than nearly true.
The akgl test renders against a 128x128 target, deliberately smaller than the
old constants: a SCALE still dividing by them misses it entirely rather than
landing somewhere plausible.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
src/sink_akgl.c, src/graphics_akgl.c, src/audio_akgl.c and src/input_akgl.c, in
the akbasic_akgl target, which is the only thing here that links SDL.
-DAKBASIC_WITH_AKGL=ON had never been configured in this repository before, and
it now builds and passes.
The sink is what section 3 has been waiting on. Its character grid comes from
akgl_text_measure(font, "A", &w, &h), the direct equivalent of the reference's
font.SizeUTF8("A") and the call that did not exist until 42b60f7. Wrapping is
done on the character grid rather than by handing SDL_ttf a wraplength, because
the cursor has to land somewhere definite: a program that PRINTs a long string
and then PRINTs again expects the second to start on the row after the first
ended, and only the code that placed the characters knows which row that is.
tests/akgl_backends.c draws into a 128x128 software renderer under the dummy
video driver and reads the pixels back -- the pattern deps/libakgl/tests/draw.c
established, which needs no display and no offscreen harness. It asserts the
seam rather than libakgl's own behaviour: a BASIC line in, a lit pixel of the
right colour out.
Four things in libakgl had to be worked around to get here. All four are
commented at their site with "filed upstream" and recorded in TODO.md section 3:
- An embedded libakgl requires SDL, SDL_image, SDL_mixer, SDL_ttf and jansson to
be *installed*. It builds its own vendored copies only when it is top-level,
and they are sitting right there in deps/libakgl/deps. Every lookup is guarded
with if(NOT TARGET ...), so this adds those five subdirectories before
add_subdirectory(deps/libakgl) -- the same trick and the same ordering
requirement akerror::akerror and akstdlib::akstdlib already need.
- akgl/controller.h does not compile on its own: it declares handlers taking an
akgl_Actor * and includes nothing that declares the type.
- There is no way to attach a 2D backend to a renderer you already have.
akgl_render_init2d() installs the vtable but also creates its own window and
writes the camera global, so it belongs to the akgl_game_init() path -- which
is exactly the path an embedding host is not on. The test assigns the six
pointers by hand.
- akgl_text_rendertextat() segfaults on a backend whose vtable is empty; it
reaches through renderer->draw_texture without checking it. Same class of
defect 42b60f7's own commit added a draw test for.
The sink's readline reports end of input rather than reading: a drawn text layer
is not a source of lines, and INPUT through one wants a line editor built on the
keystroke ring. EOF rather than an error is the contract sink.h states, so INPUT
already handles it. That editor is the next piece of work there.
70/70 core ctest with no SDL on the include path, 71/71 with the akgl suite,
clean under -Wall -Wextra, doxygen clean.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
