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akbasic/tests/language/graphics/no_device.bas

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Draw: implement the BASIC 7.0 graphics verbs GRAPHIC, COLOR, DRAW, BOX, CIRCLE, PAINT, SCALE, SSHAPE, GSHAPE and LOCATE, all against the akbasic_GraphicsBackend record rather than akgl_draw_* directly, so src/runtime_graphics.c includes no SDL and the whole group is testable in a build with no SDL on the machine. The reference lists every one of these as unimplemented, so the semantics come from Commodore BASIC 7.0 rather than from a port, and four places where a modern renderer cannot do what a C128 did are recorded in TODO.md section 5 rather than silently substituted: - CIRCLE is drawn as a polygon of inc-degree segments and akgl_draw_circle is deliberately unused. 7.0's CIRCLE takes two radii, an arc range and a rotation, so the primitive could serve only the fully-defaulted call, and a shape that changed character depending on whether the radii happened to be equal would be worse than one uniformly a polygon. - SSHAPE puts a SHAPE:<n> handle in the string variable rather than the pixels, because a value's string is a fixed 256 bytes and a region is a device surface. GSHAPE refuses a string without that prefix instead of parsing whatever digits it finds and pasting an unrelated slot. - BOX fills on a negative angle; 7.0 puts the fill flag after the rotation, which would make a filled box a seventh argument. - GRAPHIC stores its mode and honours only the one consequence that means anything here -- mode 0 is text -- while still refusing an out-of-range mode, since that is a typo worth catching. PAINT surfaces the flood fill's AKERR_OUTOFBOUNDS as an error rather than success. The device gives up when its span stack runs out having filled *part* of the region, and a program that cannot tell that happened cannot recover from it. Note the shape of that handler: HANDLE sets handled = true on the context, so a FAIL_RETURN from inside the HANDLE block hands the caller something already marked handled, whose FINISH_LOGIC then declines to pass it up and releases it -- the error disappears and PAINT reports success. Flag inside the block, raise after FINISH. COLOR, LOCATE and SCALE need no device on purpose, so a program can set itself up before a host has lent it a renderer. Adds a second golden corpus under tests/language/. The corpus in deps/basicinterpret is a submodule and nothing here may add files to it, but goal 2's new verbs still need the .bas/.txt half of their coverage. Registered under local_ so a failure names which corpus it came from. What it can cover is limited -- these verbs draw rather than print -- so the behaviour that reaches a device is asserted against tests/mockdevice.h instead. 65/65 ctest, clean under -Wall -Wextra, doxygen clean. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-07-31 08:17:48 -04:00
10 REM The standalone driver lends the script no graphics device.
20 REM COLOR, LOCATE and SCALE only touch interpreter state and must still work.
30 COLOR 1, 3
40 LOCATE 40, 50
50 SCALE 1, 640, 400
60 PRINT "STATE VERBS OK"
70 REM DRAW needs the device, and has to say which verb wanted it.
80 DRAW 1, 10, 10