snark13
c71e249a4e
First substantive commit: the entire Sprinter C compiler tree on top of
the bare README+gitignore initial commit.
What's in here:
bin/sprinter-cc — driver script invoking SDCC + linker + mkexe
libc/ — Sprinter-specific libc layer over ESTEX/BIOS
(conio, gfx, io, mem, stdio + headers)
runtime/ — crt0 variants (default/small/banked/minimal)
+ heap + bank trampolines
toolchain/ — mkexe (SprintEXE packer, C + tests)
examples/ — 30 demo programs (gfx, file I/O, env, time, …)
lib/Makefile — builds the libc archive (sprinter.lib)
docs/ — converted Sprinter manuals + asm reference samples
third_party/ — solid-c reference compiler dump + sdcc setup script
release_docs/ — packaging / release notes
gitignore overhaul:
• Drop dangerous blanket patterns: *.asm (would hide docs/samples/*.asm)
and *.exe (case-insensitive match was hiding third_party/solid-c/*.EXE
on macOS APFS). Replaced with examples/*/*.{asm,exe,…} and lib/*.lib.
• Restore tracking of toolchain/mkexe/tests/{one,big}.bin — those are
INPUT fixtures, not build outputs.
• Collapse the duplicated SDCC/C/Sdcc sections into one section per
concern (build outputs / vendored / OS-junk).
• Add .sprinter-cc-*/, build/ (catches lib/build/ too), .claude/.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
125 lines
3.6 KiB
C
125 lines
3.6 KiB
C
/*
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* gfx_text_16.c — bitmap-font text rendering for mode 0x82
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* (640×256×16, 4 bits per pixel).
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*
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* Per glyph row (8 pixels): emit 4 bytes — each byte packs two
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* adjacent pixels as (LEFT<<4) | RIGHT. A precomputed 4-entry pair
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* table maps the 2-bit source pattern (LEFT*2 + RIGHT) directly to
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* the output byte, avoiding per-pixel mask/OR.
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*
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* Currently requires byte-aligned x (x must be even); odd x is
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* silently ignored. Text grids are typically aligned.
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*/
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#include <gfx.h>
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#include <stdint.h>
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extern uint16_t _gfx_addr_base;
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extern const uint8_t *_gfx_font_ptr;
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extern void _gfx_font_ensure(void);
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static uint8_t txt_y;
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static uint8_t txt_row;
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static uint16_t txt_addr;
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/* 4-byte lookup: index = LEFT*2 + RIGHT, value = (LEFT<<4)|RIGHT. */
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static uint8_t txt_pair[4];
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/* Render one 8-pixel row using the pair table — 4 byte writes. */
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static void render_row_16(void) __naked
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{
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__asm
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di
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in a, (#0xE2)
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push af
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ld a, #0x50
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out (#0xE2), a
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ld a, (_txt_y)
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out (#0x89), a
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ld hl, (_txt_addr)
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ld a, (_txt_row)
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ld c, a ; C = rotating source bits
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ld b, #4 ; 4 output bytes
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rr16_loop:
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;; Extract two top bits of C as index A = LEFT*2 + RIGHT.
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sla c ; CY = LEFT bit; C <<= 1
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ld a, #0
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adc a, a ; A = LEFT
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sla c ; CY = RIGHT bit; C <<= 1
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adc a, a ; A = LEFT*2 + RIGHT (0..3)
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;; A = txt_pair[A]; preserve HL across the lookup.
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push hl
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ld e, a
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ld d, #0
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ld hl, #_txt_pair
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add hl, de
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ld a, (hl)
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pop hl
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ld (hl), a
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inc hl
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djnz rr16_loop
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pop af
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out (#0xE2), a
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ei
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ret
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__endasm;
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}
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static void build_pair_table(uint8_t fg, uint8_t bg)
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{
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uint8_t f = fg & 0x0F;
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uint8_t b = bg & 0x0F;
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/* HIGH nibble = LEFT, LOW nibble = RIGHT (sprinter_graphics convention). */
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txt_pair[0] = (uint8_t)((b << 4) | b); /* 00 BG BG */
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txt_pair[1] = (uint8_t)((b << 4) | f); /* 01 BG FG */
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txt_pair[2] = (uint8_t)((f << 4) | b); /* 10 FG BG */
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txt_pair[3] = (uint8_t)((f << 4) | f); /* 11 FG FG */
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}
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void gfx_putchar16(int x, int y, char c, uint8_t fg, uint8_t bg)
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{
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_gfx_font_ensure();
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if ((unsigned)x >= GFX_WIDTH_16 || (unsigned)y >= GFX_HEIGHT_16) return;
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if (x & 1) return;
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build_pair_table(fg, bg);
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uint8_t cc = (uint8_t)c;
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uint16_t base = (uint16_t)(_gfx_addr_base + ((unsigned)x >> 1));
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for (int r = 0; r < 8; r++) {
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int yy = y + r;
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if ((unsigned)yy >= GFX_HEIGHT_16) break;
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txt_y = (uint8_t)yy;
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txt_addr = base;
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txt_row = _gfx_font_ptr[r * 256 + cc];
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render_row_16();
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}
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}
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void gfx_text16(int x, int y, const char *s, uint8_t fg, uint8_t bg)
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{
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/* Build pair table once for the whole string (FG/BG don't change). */
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_gfx_font_ensure();
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if (x & 1) return;
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build_pair_table(fg, bg);
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for (; *s; s++) {
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if (x >= GFX_WIDTH_16) break;
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if ((unsigned)y >= GFX_HEIGHT_16) break;
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uint8_t cc = (uint8_t)*s;
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uint16_t base = (uint16_t)(_gfx_addr_base + ((unsigned)x >> 1));
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for (int r = 0; r < 8; r++) {
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int yy = y + r;
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if ((unsigned)yy >= GFX_HEIGHT_16) break;
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txt_y = (uint8_t)yy;
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txt_addr = base;
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txt_row = _gfx_font_ptr[r * 256 + cc];
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render_row_16();
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}
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x += 8;
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}
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}
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