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>
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src/verbs.c
10
src/verbs.c
@@ -37,19 +37,25 @@ static const akbasic_Verb VERBS[] = {
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{ "AND", AKBASIC_TOK_AND, -1, NULL, NULL },
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{ "ATN", AKBASIC_TOK_FUNCTION, 1, NULL, akbasic_fn_atn },
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{ "AUTO", AKBASIC_TOK_COMMAND_IMMEDIATE, -1, NULL, akbasic_cmd_auto },
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{ "BOX", AKBASIC_TOK_COMMAND, -1, akbasic_parse_arglist, akbasic_cmd_box },
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{ "CHR", AKBASIC_TOK_FUNCTION, 1, NULL, akbasic_fn_chr },
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{ "CIRCLE", AKBASIC_TOK_COMMAND, -1, akbasic_parse_arglist, akbasic_cmd_circle },
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{ "COLOR", AKBASIC_TOK_COMMAND, -1, akbasic_parse_arglist, akbasic_cmd_color },
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{ "COS", AKBASIC_TOK_FUNCTION, 1, NULL, akbasic_fn_cos },
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{ "DATA", AKBASIC_TOK_COMMAND, -1, akbasic_parse_data, akbasic_cmd_data },
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{ "DEF", AKBASIC_TOK_COMMAND, -1, akbasic_parse_def, akbasic_cmd_def },
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{ "DELETE", AKBASIC_TOK_COMMAND_IMMEDIATE, -1, NULL, akbasic_cmd_delete },
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{ "DIM", AKBASIC_TOK_COMMAND, -1, akbasic_parse_dim, akbasic_cmd_dim },
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{ "DLOAD", AKBASIC_TOK_COMMAND_IMMEDIATE, -1, NULL, akbasic_cmd_dload },
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{ "DRAW", AKBASIC_TOK_COMMAND, -1, akbasic_parse_draw, akbasic_cmd_draw },
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{ "DSAVE", AKBASIC_TOK_COMMAND_IMMEDIATE, -1, NULL, akbasic_cmd_dsave },
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{ "ELSE", AKBASIC_TOK_COMMAND, -1, NULL, NULL },
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{ "EXIT", AKBASIC_TOK_COMMAND, -1, NULL, akbasic_cmd_exit },
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{ "FOR", AKBASIC_TOK_COMMAND, -1, akbasic_parse_for, akbasic_cmd_for },
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{ "GOSUB", AKBASIC_TOK_COMMAND, -1, NULL, akbasic_cmd_gosub },
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{ "GOTO", AKBASIC_TOK_COMMAND, -1, NULL, akbasic_cmd_goto },
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{ "GRAPHIC", AKBASIC_TOK_COMMAND, -1, akbasic_parse_arglist, akbasic_cmd_graphic },
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{ "GSHAPE", AKBASIC_TOK_COMMAND, -1, akbasic_parse_arglist, akbasic_cmd_gshape },
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{ "HEX", AKBASIC_TOK_FUNCTION, 1, NULL, akbasic_fn_hex },
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{ "IF", AKBASIC_TOK_COMMAND, -1, akbasic_parse_if, akbasic_cmd_if },
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{ "INPUT", AKBASIC_TOK_COMMAND, -1, akbasic_parse_input, akbasic_cmd_input },
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@@ -59,12 +65,14 @@ static const akbasic_Verb VERBS[] = {
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{ "LEN", AKBASIC_TOK_FUNCTION, 1, NULL, akbasic_fn_len },
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{ "LET", AKBASIC_TOK_COMMAND, -1, akbasic_parse_let, akbasic_cmd_let },
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{ "LIST", AKBASIC_TOK_COMMAND_IMMEDIATE, -1, NULL, akbasic_cmd_list },
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{ "LOCATE", AKBASIC_TOK_COMMAND, -1, akbasic_parse_arglist, akbasic_cmd_locate },
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{ "LOG", AKBASIC_TOK_FUNCTION, 1, NULL, akbasic_fn_log },
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{ "MID", AKBASIC_TOK_FUNCTION, 3, NULL, akbasic_fn_mid },
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{ "MOD", AKBASIC_TOK_FUNCTION, 2, NULL, akbasic_fn_mod },
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{ "NEXT", AKBASIC_TOK_COMMAND, -1, NULL, akbasic_cmd_next },
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{ "NOT", AKBASIC_TOK_NOT, -1, NULL, NULL },
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{ "OR", AKBASIC_TOK_OR, -1, NULL, NULL },
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{ "PAINT", AKBASIC_TOK_COMMAND, -1, akbasic_parse_arglist, akbasic_cmd_paint },
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{ "PEEK", AKBASIC_TOK_FUNCTION, 1, NULL, akbasic_fn_peek },
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{ "POINTER", AKBASIC_TOK_FUNCTION, 1, NULL, akbasic_fn_pointer },
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{ "POINTERVAR", AKBASIC_TOK_FUNCTION, 1, NULL, akbasic_fn_pointervar },
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@@ -77,11 +85,13 @@ static const akbasic_Verb VERBS[] = {
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{ "RETURN", AKBASIC_TOK_COMMAND, -1, NULL, akbasic_cmd_return },
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{ "RIGHT", AKBASIC_TOK_FUNCTION, 2, NULL, akbasic_fn_right },
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{ "RUN", AKBASIC_TOK_COMMAND_IMMEDIATE, -1, NULL, akbasic_cmd_run },
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{ "SCALE", AKBASIC_TOK_COMMAND, -1, akbasic_parse_arglist, akbasic_cmd_scale },
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{ "SGN", AKBASIC_TOK_FUNCTION, 1, NULL, akbasic_fn_sgn },
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{ "SHL", AKBASIC_TOK_FUNCTION, 2, NULL, akbasic_fn_shl },
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{ "SHR", AKBASIC_TOK_FUNCTION, 2, NULL, akbasic_fn_shr },
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{ "SIN", AKBASIC_TOK_FUNCTION, 1, NULL, akbasic_fn_sin },
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{ "SPC", AKBASIC_TOK_FUNCTION, 1, NULL, akbasic_fn_spc },
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{ "SSHAPE", AKBASIC_TOK_COMMAND, -1, akbasic_parse_arglist, akbasic_cmd_sshape },
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{ "STEP", AKBASIC_TOK_COMMAND, -1, NULL, NULL },
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{ "STOP", AKBASIC_TOK_COMMAND, -1, NULL, akbasic_cmd_stop },
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{ "STR", AKBASIC_TOK_FUNCTION, 1, NULL, akbasic_fn_str },
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