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<a href='https://github.com/akkartik/mu/blob/main/baremetal/103grapheme.subx'>https://github.com/akkartik/mu/blob/main/baremetal/103grapheme.subx</a>
<pre id='vimCodeElement'>
<span id="L1" class="LineNr"> 1 </span><span class="subxFunction">draw-grapheme</span>: <span class="subxComment"># screen: (addr screen), g: grapheme, x: int, y: int, color: int</span>
<span id="L2" class="LineNr"> 2 </span> <span class="subxS1Comment"># . prologue</span>
<span id="L3" class="LineNr"> 3 </span> 55/push-ebp
<span id="L4" class="LineNr"> 4 </span> 89/<- %ebp 4/r32/esp
<span id="L5" class="LineNr"> 5 </span> <span class="subxS1Comment"># . save registers</span>
<span id="L6" class="LineNr"> 6 </span> 50/push-eax
<span id="L7" class="LineNr"> 7 </span> 51/push-ecx
<span id="L8" class="LineNr"> 8 </span> 52/push-edx
<span id="L9" class="LineNr"> 9 </span> 53/push-ebx
<span id="L10" class="LineNr"> 10 </span> 56/push-esi
<span id="L11" class="LineNr"> 11 </span> <span class="subxComment"># TODO: support fake screen; we currently assume 'screen' is always 0 (real)</span>
<span id="L12" class="LineNr"> 12 </span> <span class="subxComment"># var letter-bitmap/esi = font[g]</span>
<span id="L13" class="LineNr"> 13 </span> 8b/-> *(ebp+0xc) 6/r32/esi
<span id="L14" class="LineNr"> 14 </span> c1 4/subop/shift-left %esi 4/imm8
<span id="L15" class="LineNr"> 15 </span> 8d/copy-address *(esi+0x8800) 6/r32/esi <span class="subxComment"># font-start</span>
<span id="L16" class="LineNr"> 16 </span> <span class="subxComment"># if (letter-bitmap >= 0x9000) return # characters beyond ASCII currently not supported</span>
<span id="L17" class="LineNr"> 17 </span> 81 7/subop/compare %esi 0x9000/imm32
<span id="L18" class="LineNr"> 18 </span> 7d/jump-if->= $draw-grapheme:end/disp8
<span id="L19" class="LineNr"> 19 </span> <span class="subxComment"># edx = y</span>
<span id="L20" class="LineNr"> 20 </span> 8b/-> *(ebp+0x14) 2/r32/edx
<span id="L21" class="LineNr"> 21 </span> <span class="subxComment"># var ymax/ebx: int = y + 16</span>
<span id="L22" class="LineNr"> 22 </span> 8b/-> *(ebp+0x14) 3/r32/ebx
<span id="L23" class="LineNr"> 23 </span> 81 0/subop/add %ebx 0x10/imm32
<span id="L24" class="LineNr"> 24 </span> {
<span id="L25" class="LineNr"> 25 </span> <span class="subxComment"># if (y >= ymax) break</span>
<span id="L26" class="LineNr"> 26 </span> 39/compare %edx 3/r32/ebx
<span id="L27" class="LineNr"> 27 </span> 7d/jump-if->= <span class="Constant">break</span>/disp8
<span id="L28" class="LineNr"> 28 </span> <span class="subxComment"># eax = x + 7</span>
<span id="L29" class="LineNr"> 29 </span> 8b/-> *(ebp+0x10) 0/r32/eax
<span id="L30" class="LineNr"> 30 </span> 81 0/subop/add %eax 7/imm32
<span id="L31" class="LineNr"> 31 </span> <span class="subxComment"># var xmin/ecx: int = x</span>
<span id="L32" class="LineNr"> 32 </span> 8b/-> *(ebp+0x10) 1/r32/ecx
<span id="L33" class="LineNr"> 33 </span> <span class="subxComment"># var row-bitmap/ebx: int = *letter-bitmap</span>
<span id="L34" class="LineNr"> 34 </span> 53/push-ebx
<span id="L35" class="LineNr"> 35 </span> 8b/-> *esi 3/r32/ebx
<span id="L36" class="LineNr"> 36 </span> {
<span id="L37" class="LineNr"> 37 </span> <span class="subxComment"># if (x < xmin) break</span>
<span id="L38" class="LineNr"> 38 </span> 39/compare %eax 1/r32/ecx
<span id="L39" class="LineNr"> 39 </span> 7c/jump-if-< <span class="Constant">break</span>/disp8
<span id="L40" class="LineNr"> 40 </span> <span class="subxComment"># shift LSB from row-bitmap into carry flag (CF)</span>
<span id="L41" class="LineNr"> 41 </span> c1 5/subop/shift-right-logical %ebx 1/imm8
<span id="L42" class="LineNr"> 42 </span> <span class="subxComment"># if LSB, draw a pixel</span>
<span id="L43" class="LineNr"> 43 </span> {
<span id="L44" class="LineNr"> 44 </span> 73/jump-if-not-CF <span class="Constant">break</span>/disp8
<span id="L45" class="LineNr"> 45 </span> (<a href='101screen.subx.html#L3'>pixel</a> *(ebp+8) %eax %edx *(ebp+0x18))
<span id="L46" class="LineNr"> 46 </span> }
<span id="L47" class="LineNr"> 47 </span> <span class="subxComment"># --x</span>
<span id="L48" class="LineNr"> 48 </span> 48/decrement-eax
<span id="L49" class="LineNr"> 49 </span> <span class="subxComment">#</span>
<span id="L50" class="LineNr"> 50 </span> eb/jump <span class="Constant">loop</span>/disp8
<span id="L51" class="LineNr"> 51 </span> }
<span id="L52" class="LineNr"> 52 </span> <span class="subxComment"># reclaim row-bitmap</span>
<span id="L53" class="LineNr"> 53 </span> 5b/pop-to-ebx
<span id="L54" class="LineNr"> 54 </span> <span class="subxComment"># ++y</span>
<span id="L55" class="LineNr"> 55 </span> 42/increment-edx
<span id="L56" class="LineNr"> 56 </span> <span class="subxComment"># next bitmap row</span>
<span id="L57" class="LineNr"> 57 </span> 46/increment-esi
<span id="L58" class="LineNr"> 58 </span> <span class="subxComment">#</span>
<span id="L59" class="LineNr"> 59 </span> eb/jump <span class="Constant">loop</span>/disp8
<span id="L60" class="LineNr"> 60 </span> }
<span id="L61" class="LineNr"> 61 </span><span class="Constant">$draw-grapheme:end</span>:
<span id="L62" class="LineNr"> 62 </span> <span class="subxS1Comment"># . restore registers</span>
<span id="L63" class="LineNr"> 63 </span> 5e/pop-to-esi
<span id="L64" class="LineNr"> 64 </span> 5b/pop-to-ebx
<span id="L65" class="LineNr"> 65 </span> 5a/pop-to-edx
<span id="L66" class="LineNr"> 66 </span> 59/pop-to-ecx
<span id="L67" class="LineNr"> 67 </span> 58/pop-to-eax
<span id="L68" class="LineNr"> 68 </span> <span class="subxS1Comment"># . epilogue</span>
<span id="L69" class="LineNr"> 69 </span> 89/<- %esp 5/r32/ebp
<span id="L70" class="LineNr"> 70 </span> 5d/pop-to-ebp
<span id="L71" class="LineNr"> 71 </span> c3/return
<span id="L72" class="LineNr"> 72 </span>
<span id="L73" class="LineNr"> 73 </span><span class="subxFunction">cursor-position</span>: <span class="subxComment"># screen: (addr screen) -> _/eax: int, _/ecx: int</span>
<span id="L74" class="LineNr"> 74 </span> <span class="subxS1Comment"># . prologue</span>
<span id="L75" class="LineNr"> 75 </span> 55/push-ebp
<span id="L76" class="LineNr"> 76 </span> 89/<- %ebp 4/r32/esp
<span id="L77" class="LineNr"> 77 </span> <span class="subxComment"># TODO: support fake screen; we currently assume 'screen' is always 0 (real)</span>
<span id="L78" class="LineNr"> 78 </span> 8b/-> *<span class="SpecialChar"><a href='103grapheme.subx.html#L107'>Default-next-x</a></span> 0/r32/eax
<span id="L79" class="LineNr"> 79 </span> 8b/-> *<span class="SpecialChar"><a href='103grapheme.subx.html#L110'>Default-next-y</a></span> 1/r32/ecx
<span id="L80" class="LineNr"> 80 </span><span class="Constant">$cursor-position:end</span>:
<span id="L81" class="LineNr"> 81 </span> <span class="subxS1Comment"># . epilogue</span>
<span id="L82" class="LineNr"> 82 </span> 89/<- %esp 5/r32/ebp
<span id="L83" class="LineNr"> 83 </span> 5d/pop-to-ebp
<span id="L84" class="LineNr"> 84 </span> c3/return
<span id="L85" class="LineNr"> 85 </span>
<span id="L86" class="LineNr"> 86 </span><span class="subxFunction">set-cursor-position</span>: <span class="subxComment"># screen: (addr screen), x: int, y: int</span>
<span id="L87" class="LineNr"> 87 </span> <span class="subxS1Comment"># . prologue</span>
<span id="L88" class="LineNr"> 88 </span> 55/push-ebp
<span id="L89" class="LineNr"> 89 </span> 89/<- %ebp 4/r32/esp
<span id="L90" class="LineNr"> 90 </span> <span class="subxS1Comment"># . save registers</span>
<span id="L91" class="LineNr"> 91 </span> 50/push-eax
<span id="L92" class="LineNr"> 92 </span> <span class="subxComment"># TODO: support fake screen; we currently assume 'screen' is always 0 (real)</span>
<span id="L93" class="LineNr"> 93 </span> 8b/-> *(ebp+0xc) 0/r32/eax
<span id="L94" class="LineNr"> 94 </span> 89/<- *<span class="SpecialChar"><a href='103grapheme.subx.html#L107'>Default-next-x</a></span> 0/r32/eax
<span id="L95" class="LineNr"> 95 </span> 8b/-> *(ebp+0x10) 0/r32/eax
<span id="L96" class="LineNr"> 96 </span> 89/<- *<span class="SpecialChar"><a href='103grapheme.subx.html#L110'>Default-next-y</a></span> 0/r32/eax
<span id="L97" class="LineNr"> 97 </span><span class="Constant">$set-cursor-position:end</span>:
<span id="L98" class="LineNr"> 98 </span> <span class="subxS1Comment"># . restore registers</span>
<span id="L99" class="LineNr"> 99 </span> 58/pop-to-eax
<span id="L100" class="LineNr">100 </span> <span class="subxS1Comment"># . epilogue</span>
<span id="L101" class="LineNr">101 </span> 89/<- %esp 5/r32/ebp
<span id="L102" class="LineNr">102 </span> 5d/pop-to-ebp
<span id="L103" class="LineNr">103 </span> c3/return
<span id="L104" class="LineNr">104 </span>
<span id="L105" class="LineNr">105 </span>== data
<span id="L106" class="LineNr">106 </span>
<span id="L107" class="LineNr">107 </span><span class="SpecialChar">Default-next-x</span>:
<span id="L108" class="LineNr">108 </span> 0/imm32
<span id="L109" class="LineNr">109 </span>
<span id="L110" class="LineNr">110 </span><span class="SpecialChar">Default-next-y</span>:
<span id="L111" class="LineNr">111 </span> 0/imm32
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