| 0,0 → 1,188 |
|---|
| draw_triangle: |
| ;----------in - eax - x1 shl 16 + y1 |
| ;------------- -ebx - x2 shl 16 + y2 |
| ;---------------ecx - x3 shl 16 + y3 |
| ;---------------edx - color 0x00rrggbb |
| ;---------------edi - pointer to screen buffer |
| @ch3: |
| cmp ax,bx |
| jg @ch1 |
| @ch4: ; sort parameters |
| cmp bx,cx |
| jg @ch2 |
| jle @chEnd |
| @ch1: |
| xchg eax,ebx |
| jmp @ch4 |
| @ch2: |
| xchg ebx,ecx |
| jmp @ch3 |
| @chEnd: |
| mov dword[@y1],eax ; ....and store to user friendly variables |
| mov dword[@y2],ebx |
| mov dword[@y3],ecx |
| mov [@col],edx |
| mov edx,eax ; eax,ebx,ecx are ORd together into edx which means that |
| or edx,ebx ; if any *one* of them is negative a sign flag is raised |
| or edx,ecx |
| test edx,80008000h ; Check both X&Y at once |
| jne @end_triangle |
| |
| cmp [@x1],SIZE_X ; { |
| jg @end_triangle |
| cmp [@x2],SIZE_X ; This can be optimized with effort |
| jg @end_triangle |
| cmp [@x3],SIZE_X |
| jg @end_triangle ; } |
| |
| shr eax,16 |
| shr ebx,16 |
| shr ecx,16 |
| |
| neg ax ; calculate delta 12 |
| add ax,bx |
| cwde |
| shl eax,ROUND |
| cdq |
| mov bx,[@y2] |
| mov cx,[@y1] |
| sub bx,cx |
| ;cmp ebx,0 |
| jne @noZero1 |
| mov [@dx12],0 |
| jmp @yesZero1 |
| @noZero1: |
| idiv ebx |
| mov [@dx12],eax |
| @yesZero1: |
| |
| mov ax,[@x3] ; calculate delta 13 |
| sub ax,[@x1] |
| cwde |
| shl eax,ROUND |
| cdq |
| mov bx,[@y3] |
| mov cx,[@y1] |
| sub bx,cx |
| ;cmp ebx,0 |
| jne @noZero2 |
| mov [@dx13],0 |
| jmp @yesZero2 |
| @noZero2: |
| idiv ebx |
| mov [@dx13],eax |
| @yesZero2: |
| |
| mov ax,[@x3] ; calculate delta 23 [dx23] |
| sub ax,[@x2] |
| cwde |
| shl eax,ROUND |
| cdq |
| mov bx,[@y3] |
| mov cx,[@y2] |
| sub bx,cx |
| ;cmp ebx,0 |
| jne @noZero3 |
| mov [@dx23],0 |
| jmp @yesZero3 |
| @noZero3: |
| idiv ebx |
| mov [@dx23],eax |
| @yesZero3: |
| |
| movzx eax,word[@x1] ; eax - xk1 |
| shl eax,ROUND |
| mov ebx,eax ; ebx - xk2 |
| movzx esi,word[@y1] ; esi - y |
| @next_line1: |
| mov ecx,eax ; ecx - x11 |
| sar ecx,ROUND |
| mov edx,ebx ; edx - x12 |
| sar edx,ROUND |
| cmp ecx,edx |
| jle @nochg |
| xchg ecx,edx |
| @nochg: |
| pusha |
| mov ebx,ecx |
| sub edx,ecx |
| mov ecx,edx |
| mov edx,esi |
| mov eax,[@col] |
| call @horizontal_line |
| popa |
| add eax,[@dx13] |
| add ebx,[@dx12] |
| inc esi |
| cmp si,[@y2] |
| jl @next_line1 |
| |
| movzx esi,word[@y2] |
| movzx ebx,word[@x2] |
| shl ebx,ROUND |
| @next_line2: |
| mov ecx,eax |
| sar ecx,ROUND |
| mov edx,ebx |
| sar edx,ROUND |
| cmp ecx,edx |
| jle @nochg1 |
| xchg ecx,edx |
| @nochg1: |
| pusha |
| mov ebx,ecx |
| sub edx,ecx |
| mov ecx,edx |
| mov edx,esi |
| mov eax,[@col] |
| call @horizontal_line |
| popa |
| add eax,[@dx13] |
| add ebx,[@dx23] |
| inc esi |
| cmp si,[@y3] |
| jl @next_line2 |
| @end_triangle: |
| ret |
| |
| @horizontal_line: |
| ;---------in |
| ;---------eax - color of line, 0x00RRGGBB |
| ;---------ebx - x1 - x position of line begin |
| ;---------ecx - lenght of line |
| ;---------edx - y position of line |
| ;---------edi - pointer to buffer |
| jcxz @end_hor_l |
| ; or edx,edx |
| ; jl @end_hor_l |
| cmp edx,SIZE_Y |
| jg @end_hor_l |
| push eax |
| mov eax,SIZE_X*3 |
| mul edx |
| add edi,eax ; calculate line begin adress |
| ;add edi,ebx |
| ;shl ebx,1 |
| lea edi,[edi+ebx*2] |
| add edi,ebx |
| pop eax |
| cld |
| ;mov dword[edi-3],0000FF00h |
| @ddraw: ; Drawing horizontally: |
| ;push eax |
| stosd ; 4 bytes at a time |
| dec edi ; point to the 4th |
| ;shr eax,16 |
| ;stosb |
| ;pop eax |
| ;pusha ; If you want to draw pixel-by-pixel |
| ; mov eax,7 ; put image |
| ; mov ebx,screen |
| ; mov ecx,SIZE_X shl 16 + SIZE_Y |
| ; mov edx,5 shl 16 + 20 |
| ; int 0x40 |
| ;popa |
| loop @ddraw |
| mov byte[edi],0 ; The last 4th will be reset |
| @end_hor_l: |
| ret |