754 lines
14 KiB
NASM
754 lines
14 KiB
NASM
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;; Copyright (c) 1992,1993-1995 Argonaut Technologies Limited. All rights reserved.
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;;
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;; $Id: tt24_pi.asm 1.1 1996/09/26 19:04:09 JOHNG Exp $
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;; $Locker: $
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;;
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;; 24 bit RGB_888 888 mode
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;;
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;; Triangle scan convertion and rendering
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;;
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;; Perfect scan, integer vertices
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;;
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.386p
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.model flat,c
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include drv.inc
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include 586_macs.inc
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if 1
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SHOW_CODESIZE macro _name,_total
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%out _name = _total
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endm
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else
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SHOW_CODESIZE macro x,y
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endm
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endif
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X equ 0
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Y equ 1
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Z equ 2
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_X equ 0
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_Y equ 4
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_Z equ 8
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;; Setup some macros that are used to put colour and texture buffers in different
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;; segments
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;;
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if 0
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CSEG equ es:
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DSEG equ
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TSEG equ
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SETUP_SEGS macro
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push es
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mov es,word ptr work.colour.base+4
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endm
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RESTORE_SEGS macro
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pop es
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endm
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else
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CSEG equ
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DSEG equ
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TSEG equ
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SETUP_SEGS macro
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endm
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RESTORE_SEGS macro
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endm
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endif
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;; Fast eax /= 3
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divide3 macro
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mov ecx,eax
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lea eax,[eax+4*eax]
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mov edx,eax
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sal edx,4
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add eax,edx
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mov edx,eax
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sal edx,8
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add eax,edx
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lea eax,[ecx+eax*2]
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shr eax,17
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endm
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;; Various macros for generating the triangle renderers
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;;
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; Divide edx:eax by g_divisor with no overflow
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;
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; Assumes Z flag has sign of numerator
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;
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; Trashes ebx
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;
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;
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GDIVIDE macro dirn
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local negative,done,overflow
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mov ebx,g_divisor
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js negative
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cmp ebx,edx
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jbe overflow
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div ebx
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ifidni <dirn>,<b>
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neg eax
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endif
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jmp done
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negative: neg edx
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neg eax
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sbb edx,0
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cmp ebx,edx
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jbe overflow
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div ebx
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ifidni <dirn>,<f>
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neg eax
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endif
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overflow:
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done:
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endm
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; Comparison that change sense with rendering direction
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;
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CMP_f macro a,b
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cmp a,b
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endm
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CMP_b macro a,b
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cmp b,a
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endm
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; Setup of an integer, perfect scan triangle
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;
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; Leave g_divisor in eax, with sign of g_divisor in flags
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;
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SETUP_PI macro
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_setup_start = $
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; Get Y components of vertices
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;
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mov eax,[esi].brp_vertex.comp[C_SY*4]
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mov ebx,[edi].brp_vertex.comp[C_SY*4]
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mov ecx,[ebp].brp_vertex.comp[C_SY*4]
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; Sort pointers and values in order of y value
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;
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cmp eax,ebx
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jg short sort_3
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cmp ebx,ecx
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jle short sort_done
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; abc
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cmp eax,ecx
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jg short sort_2
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; acb
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SWAP edi,ebp
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jmp short sort_done
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sort_2:
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; cab
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SWAP edi,ebp
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SWAP esi,edi
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jmp short sort_done
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sort_3:
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cmp ecx,ebx
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jg short sort_4
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; cba
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SWAP esi,ebp
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jmp short sort_done
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sort_4: cmp eax,ecx
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jg short sort_5
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; bac
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SWAP esi,edi
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jmp short sort_done
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sort_5:
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; bca
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SWAP esi,edi
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SWAP edi,ebp
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sort_done:
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if 1
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; Work out integer vertex values
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;
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; XXX Should really do this at projection time
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;
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mov eax,[esi].brp_vertex.comp[C_SX*4]
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mov ebx,[edi].brp_vertex.comp[C_SX*4]
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mov ecx,[ebp].brp_vertex.comp[C_SX*4]
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sar eax,16
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sar ebx,16
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sar ecx,16
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mov vertex_0[_X],eax
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mov vertex_1[_X],ebx
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mov vertex_2[_X],ecx
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mov eax,[esi].brp_vertex.comp[C_SY*4]
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mov ebx,[edi].brp_vertex.comp[C_SY*4]
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mov ecx,[ebp].brp_vertex.comp[C_SY*4]
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sar eax,16
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sar ebx,16
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sar ecx,16
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mov vertex_0[_Y],eax
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mov vertex_1[_Y],ebx
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mov vertex_2[_Y],ecx
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endif
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; Work out top.count and bot.count - the heights of each part
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; of the triangle
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;
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cmp eax,ecx ; Check for zero height polys
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je quit
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; Work out deltas and gradients along edges
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;
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; top short edge
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;
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mov edx,vertex_1[_X] ; work.top.x
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sub edx,vertex_0[_X]
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mov work.top.x,edx
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mov ebx,vertex_1[_Y] ; work.top.y
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sub ebx,vertex_0[_Y]
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mov work.top.y,ebx
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mov work.top.count,ebx
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je short no_top
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FIX_DIV ; work.top.grad = work.top.x/work.top.y
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idiv ebx
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mov work.top.grad,eax
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mov word ptr work.top.d_f+2,ax
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sar eax,16
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add eax,work.colour.stride_p
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mov work.top.d_i,eax
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no_top:
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; bottom short edge (don't need to save deltas)
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;
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mov edx,vertex_2[_X] ; work.bot.x
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sub edx,vertex_1[_X]
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mov ebx,vertex_2[_Y] ; work.bot.y
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sub ebx,vertex_1[_Y]
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mov work.bot.count,ebx
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je short no_bottom
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FIX_DIV ; work.bot.grad = work.bot.x/work.bot.y
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idiv ebx
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mov work.bot.grad,eax
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mov word ptr work.bot.d_f+2,ax
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sar eax,16
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add eax,work.colour.stride_p
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mov work.bot.d_i,eax
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no_bottom:
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; long edge
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;
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mov edx,vertex_2[_X] ; work.main.x
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sub edx,vertex_0[_X]
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mov work.main.x,edx
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mov ebx,vertex_2[_Y] ; work.main.y
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sub ebx,vertex_0[_Y]
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mov work.main.y,ebx
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FIX_DIV ; work.main.grad = work.main.x/work.main.y
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idiv ebx
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mov work.main.grad,eax
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mov word ptr work.main.d_f+2,ax
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sar eax,16
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add eax,work.colour.stride_p
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mov work.main.d_i,eax
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; Work out start values for edges as pixel offsets
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;
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mov ebx,work.colour.stride_p
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;mov ecx,dword ptr work.colour.base ; not needed here
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mov eax,vertex_0[_Y]
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imul ebx
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add eax,vertex_0[_X]
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mov work.main.f,080000000h
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mov work.main.i,eax
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;add eax,ecx ; not needed
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mov work.top.f,080000000h
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mov work.top.i,eax
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mov eax,vertex_1[_Y]
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imul ebx
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add eax,vertex_1[_X]
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;add eax,ecx ; not needed here
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mov work.bot.f,080000000h
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mov work.bot.i,eax
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; Work out divisor for use in parameter gradient calcs.
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;
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mov eax,work.main.x
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imul work.top.y
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mov ebx,eax
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mov eax,work.top.x
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imul work.main.y
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sub eax,ebx
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je quit ; quit if g_divisor is 0
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; Leave g_divisor in eax
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endm
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; Per parameter initialisation of perfect scan, integer vertex triangle
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;
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PARAM_PI_DIRN macro vparam,param,dirn
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; d_p_x = (d_p_1.work.main.y - d_p_2.work.top.y)/g_denom
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;
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mov eax,[ebp].brp_vertex.vparam ; d_p_2
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sub eax,[esi].brp_vertex.vparam
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push eax
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imul work.top.y
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mov ebx,eax
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mov ecx,edx
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mov eax,[edi].brp_vertex.vparam ; d_p_1
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sub eax,[esi].brp_vertex.vparam
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push eax
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imul work.main.y
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sub eax,ebx
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sbb edx,ecx
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GDIVIDE dirn
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mov param.grad_x,eax
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; d_p_y = (d_p_2.work.top.x - d_p_1.work.main.x)/g_denom
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;
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pop eax ; d_p_1
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imul work.main.x
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mov ebx,eax
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mov ecx,edx
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pop eax ; d_p_2
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imul work.top.x
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sub eax,ebx
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sbb edx,ecx
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GDIVIDE dirn
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mov param.grad_y,eax
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; Initialise parameter from top vertex
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;
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mov eax,[esi].brp_vertex.vparam
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mov ebx,param.grad_x
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sar ebx,1
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adc eax,ebx
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mov param.current,eax
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; Work out parameter increments per scanline
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;
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movsx eax,word ptr work.main.grad+2
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imul param.grad_x
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add eax,param.grad_y
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mov param.d_nocarry,eax
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add eax,param.grad_x
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mov param.d_carry,eax
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endm
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.data
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db '$Id: tt24_pi.asm 1.1 1996/09/26 19:04:09 JOHNG Exp $',0
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align 4
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temp_b dd 0
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temp_g dd 0
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temp_r dd 0
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p0_offset_x dd 0 ; Offset of start pixel centre from vertex 0
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p0_offset_y dd 0
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temp_i dd 0
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temp_u dd 0
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temp_v dd 0
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; Integer vertex poitisions
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;
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vertex_0 dd 2 dup(?)
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vertex_1 dd 2 dup(?)
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vertex_2 dd 2 dup(?)
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g_divisor dd 0 ; Bottom of param. gradient calc.
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.code
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if PARTS and PART_24
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; void TriangleRenderPI_RGB_888(struct br_vertex *pvertex_0,
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; struct br_vertex *pvertex_1,
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; struct br_vertex *pvertex_2);
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;
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; C stub directly to triangle renderer
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;
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TriangleRenderPI_RGB_888 proc uses eax ebx ecx edx esi edi,
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pblock : ptr dword,
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pvertex_0 : ptr word,
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pvertex_1 : ptr word,
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pvertex_2 : ptr word
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; Get pointers to vertex structures and colour
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;
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; eax = colour
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; esi = vertex 0
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; edi = vertex 1
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; ebp = vertex 2
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;
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push ebp
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SETUP_SEGS
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mov esi,pvertex_0
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mov edi,pvertex_1
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mov ebp,pvertex_2
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call RawTriangle_PI_RGB_888
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|
|
RESTORE_SEGS
|
||
|
|
pop ebp
|
||
|
|
ret
|
||
|
|
TriangleRenderPI_RGB_888 endp
|
||
|
|
|
||
|
|
; Trapezoid loop for flat shaded faces
|
||
|
|
;
|
||
|
|
; Arguments control:
|
||
|
|
; whether loop uses 'top' or 'bottom' variables
|
||
|
|
; which direction scanline are rendered from the long edge
|
||
|
|
;
|
||
|
|
TRAPEZOID_PI_RGB_888 macro half,dirn
|
||
|
|
local scan_loop,pixel_loop,pixel_behind,no_pixels
|
||
|
|
local start_carried,done_trapezoid
|
||
|
|
|
||
|
|
cmp work.half.count,0
|
||
|
|
je done_trapezoid
|
||
|
|
|
||
|
|
mov ecx,work.half.i
|
||
|
|
|
||
|
|
; Prepare for next iteration of loop
|
||
|
|
;
|
||
|
|
scan_loop: push esi
|
||
|
|
push edx
|
||
|
|
push ecx
|
||
|
|
|
||
|
|
mov ebx,work.colour.base
|
||
|
|
|
||
|
|
lea esi,[esi+esi*2] ; colour buffer
|
||
|
|
lea ecx,[ecx+ecx*2]
|
||
|
|
|
||
|
|
; Render same colour pixels along scanline (forwards or backwards)
|
||
|
|
;
|
||
|
|
; bl: colour
|
||
|
|
; ecx: address of end of scanline
|
||
|
|
; esi: frame buffer ptr
|
||
|
|
;
|
||
|
|
CMP_&dirn esi,ecx
|
||
|
|
jae short no_pixels
|
||
|
|
mov al,byte ptr temp_b+2
|
||
|
|
mov ah,byte ptr temp_g+2
|
||
|
|
mov dl,byte ptr temp_r+2
|
||
|
|
|
||
|
|
pixel_loop:
|
||
|
|
ifidni <dirn>,<b>
|
||
|
|
sub esi,3 ; ptr--
|
||
|
|
endif
|
||
|
|
mov CSEG [esi+ebx],al ; b
|
||
|
|
mov CSEG [esi+ebx+1],ah ; g
|
||
|
|
mov CSEG [esi+ebx+2],dl ; r
|
||
|
|
pixel_behind:
|
||
|
|
|
||
|
|
ifidni <dirn>,<f>
|
||
|
|
add esi,3 ; ptr++
|
||
|
|
endif
|
||
|
|
CMP_&dirn esi,ecx
|
||
|
|
jb short pixel_loop
|
||
|
|
no_pixels:
|
||
|
|
|
||
|
|
; Updates for next scanline:
|
||
|
|
;
|
||
|
|
pop ecx
|
||
|
|
pop edx
|
||
|
|
pop esi
|
||
|
|
mov edi,work.half.d_f
|
||
|
|
mov eax,work.main.d_f
|
||
|
|
add work.half.f,edi ; x_end += work.main.grad_end (fraction)
|
||
|
|
adc ecx,work.half.d_i ; endptr += integer(dx_end)+CARRY
|
||
|
|
|
||
|
|
add work.main.f,eax ; x+= work.main.grad (fraction)
|
||
|
|
jc start_carried
|
||
|
|
|
||
|
|
add esi,work.main.d_i ; fb_offset+=delta+CARRY
|
||
|
|
add edx,work.pz.d_nocarry
|
||
|
|
|
||
|
|
dec work.half.count
|
||
|
|
jne scan_loop
|
||
|
|
jmp short done_trapezoid
|
||
|
|
|
||
|
|
start_carried: adc esi,work.main.d_i ; fb_offset+=delta+CARRY
|
||
|
|
|
||
|
|
dec work.half.count
|
||
|
|
jne scan_loop
|
||
|
|
done_trapezoid:
|
||
|
|
endm
|
||
|
|
|
||
|
|
; Triangle_PI_RGB_888
|
||
|
|
;
|
||
|
|
; Render a triangle into frame buffer
|
||
|
|
;
|
||
|
|
; Flat colour
|
||
|
|
; Integer vertices
|
||
|
|
; Perfect point sampling
|
||
|
|
;
|
||
|
|
; esi = vertex 0 pointer
|
||
|
|
; edi = vertex 1 pointer
|
||
|
|
; ebp = vertex 2 pointer
|
||
|
|
;
|
||
|
|
RawTriangle_PI_RGB_888 proc
|
||
|
|
|
||
|
|
mov eax,[esi].brp_vertex.comp[C_R*4]
|
||
|
|
mov ebx,[esi].brp_vertex.comp[C_G*4]
|
||
|
|
mov ecx,[esi].brp_vertex.comp[C_B*4]
|
||
|
|
mov temp_r,eax
|
||
|
|
mov temp_g,ebx
|
||
|
|
mov temp_b,ecx
|
||
|
|
|
||
|
|
SETUP_PI
|
||
|
|
|
||
|
|
mov esi,work.main.i
|
||
|
|
|
||
|
|
jl reversed
|
||
|
|
mov g_divisor,eax
|
||
|
|
|
||
|
|
; Scan forwards
|
||
|
|
;
|
||
|
|
TRAPEZOID_PI_RGB_888 top,f
|
||
|
|
TRAPEZOID_PI_RGB_888 bot,f
|
||
|
|
quit: ret
|
||
|
|
|
||
|
|
; Scan backwards
|
||
|
|
;
|
||
|
|
reversed:
|
||
|
|
neg eax
|
||
|
|
mov g_divisor,eax
|
||
|
|
|
||
|
|
TRAPEZOID_PI_RGB_888 top,b
|
||
|
|
TRAPEZOID_PI_RGB_888 bot,b
|
||
|
|
ret
|
||
|
|
|
||
|
|
|
||
|
|
SHOW_CODESIZE <RawTriangle_PI_RGB_888>,<%($-_setup_start)>
|
||
|
|
|
||
|
|
RawTriangle_PI_RGB_888 endp
|
||
|
|
|
||
|
|
endif
|
||
|
|
if PARTS and PART_24
|
||
|
|
|
||
|
|
; void TriangleRenderPII_RGB_888(struct br_vertex *pvertex_0,
|
||
|
|
; struct br_vertex *pvertex_1,
|
||
|
|
; struct br_vertex *pvertex_2);
|
||
|
|
;
|
||
|
|
; C stub directly to triangle renderer
|
||
|
|
;
|
||
|
|
TriangleRenderPII_RGB_888 proc uses eax ebx ecx edx esi edi,
|
||
|
|
pblock : ptr dword,
|
||
|
|
pvertex_0 : ptr word,
|
||
|
|
pvertex_1 : ptr word,
|
||
|
|
pvertex_2 : ptr word
|
||
|
|
|
||
|
|
; Get pointers to vertex structures and colour
|
||
|
|
;
|
||
|
|
; eax = colour
|
||
|
|
; esi = vertex 0
|
||
|
|
; edi = vertex 1
|
||
|
|
; ebp = vertex 2
|
||
|
|
;
|
||
|
|
push ebp
|
||
|
|
SETUP_SEGS
|
||
|
|
|
||
|
|
mov esi,pvertex_0
|
||
|
|
mov edi,pvertex_1
|
||
|
|
mov ebp,pvertex_2
|
||
|
|
call RawTriangle_PII_RGB_888
|
||
|
|
|
||
|
|
RESTORE_SEGS
|
||
|
|
pop ebp
|
||
|
|
ret
|
||
|
|
TriangleRenderPII_RGB_888 endp
|
||
|
|
|
||
|
|
; Trapezoid loop for gouraud shaded faces
|
||
|
|
;
|
||
|
|
; Arguments control:
|
||
|
|
; whether loop uses 'top' or 'bottom' variables
|
||
|
|
; which direction scanline are rendered from the long edge
|
||
|
|
;
|
||
|
|
TRAPEZOID_PII_RGB_888 macro half,dirn
|
||
|
|
local scan_loop,pixel_loop,pixel_behind,no_pixels
|
||
|
|
local start_carried,done_trapezoid
|
||
|
|
|
||
|
|
cmp work.half.count,0
|
||
|
|
je done_trapezoid
|
||
|
|
|
||
|
|
mov ecx,work.half.i
|
||
|
|
|
||
|
|
; Prepare for next iteration of loop
|
||
|
|
;
|
||
|
|
scan_loop:
|
||
|
|
push esi
|
||
|
|
push edx
|
||
|
|
push ecx
|
||
|
|
|
||
|
|
mov eax,work.pr.current
|
||
|
|
mov temp_r,eax
|
||
|
|
mov eax,work.pg.current
|
||
|
|
mov temp_g,eax
|
||
|
|
mov eax,work.pb.current
|
||
|
|
mov temp_b,eax
|
||
|
|
|
||
|
|
mov ebx,work.colour.base
|
||
|
|
|
||
|
|
lea esi,[esi+esi*2] ; colour buffer
|
||
|
|
lea ecx,[ecx+ecx*2]
|
||
|
|
|
||
|
|
; Render same colour pixels along scanline (forwards or backwards)
|
||
|
|
;
|
||
|
|
; bl: colour
|
||
|
|
; ecx: address of end of scanline
|
||
|
|
; esi: frame buffer ptr
|
||
|
|
;
|
||
|
|
CMP_&dirn esi,ecx
|
||
|
|
jae short no_pixels
|
||
|
|
pixel_loop:
|
||
|
|
|
||
|
|
ifidni <dirn>,<b>
|
||
|
|
mov eax,work.pr.grad_x
|
||
|
|
sub temp_r,eax
|
||
|
|
mov eax,work.pg.grad_x
|
||
|
|
sub temp_g,eax
|
||
|
|
mov eax,work.pb.grad_x
|
||
|
|
sub temp_b,eax
|
||
|
|
|
||
|
|
sub esi,3 ; ptr--
|
||
|
|
endif
|
||
|
|
|
||
|
|
mov al,byte ptr temp_b+2
|
||
|
|
mov CSEG [esi+ebx],al ; *ptr = colour (blue) SE
|
||
|
|
mov al,byte ptr temp_g+2
|
||
|
|
mov CSEG [esi+ebx+1],al
|
||
|
|
mov al,byte ptr temp_r+2
|
||
|
|
mov CSEG [esi+ebx+2],al
|
||
|
|
pixel_behind:
|
||
|
|
|
||
|
|
ifidni <dirn>,<f>
|
||
|
|
mov eax,work.pr.grad_x
|
||
|
|
add temp_r,eax
|
||
|
|
mov eax,work.pg.grad_x
|
||
|
|
add temp_g,eax
|
||
|
|
mov eax,work.pb.grad_x
|
||
|
|
add temp_b,eax
|
||
|
|
add esi,3 ; ptr++
|
||
|
|
endif
|
||
|
|
CMP_&dirn esi,ecx
|
||
|
|
jb short pixel_loop
|
||
|
|
|
||
|
|
no_pixels:
|
||
|
|
|
||
|
|
; Updates for next scanline:
|
||
|
|
;
|
||
|
|
pop ecx
|
||
|
|
pop edx
|
||
|
|
pop esi
|
||
|
|
mov edi,work.half.d_f
|
||
|
|
mov eax,work.main.d_f
|
||
|
|
|
||
|
|
add work.half.f,edi ; x_end += work.main.grad_end (fraction)
|
||
|
|
adc ecx,work.half.d_i ; endptr += integer(dx_end)+CARRY
|
||
|
|
|
||
|
|
add work.main.f,eax ; x+= work.main.grad (fraction)
|
||
|
|
jc start_carried
|
||
|
|
|
||
|
|
add esi,work.main.d_i ; fb_offset+=delta+CARRY
|
||
|
|
|
||
|
|
mov eax,work.pr.d_nocarry ; red
|
||
|
|
add work.pr.current,eax ; red
|
||
|
|
mov eax,work.pg.d_nocarry ; green
|
||
|
|
add work.pg.current,eax ; green
|
||
|
|
mov eax,work.pb.d_nocarry ; blue
|
||
|
|
add work.pb.current,eax ; blue
|
||
|
|
|
||
|
|
dec work.half.count
|
||
|
|
jne scan_loop
|
||
|
|
jmp short done_trapezoid
|
||
|
|
|
||
|
|
start_carried: adc esi,work.main.d_i ; fb_offset+=delta+CARRY
|
||
|
|
|
||
|
|
mov eax,work.pr.d_carry ; red
|
||
|
|
add work.pr.current,eax ; red
|
||
|
|
mov eax,work.pg.d_carry ; green
|
||
|
|
add work.pg.current,eax ; green
|
||
|
|
mov eax,work.pb.d_carry ; blue
|
||
|
|
add work.pb.current,eax ; blue
|
||
|
|
|
||
|
|
dec work.half.count
|
||
|
|
jne scan_loop
|
||
|
|
done_trapezoid:
|
||
|
|
endm
|
||
|
|
|
||
|
|
; RawTriangle_PII_RGB_888
|
||
|
|
;
|
||
|
|
; Render a triangle into frame buffer
|
||
|
|
;
|
||
|
|
; Linearly interpolated colour index
|
||
|
|
; Integer vertices
|
||
|
|
; Perfect point sampling
|
||
|
|
;
|
||
|
|
; esi = vertex 0 pointer
|
||
|
|
; edi = vertex 1 pointer
|
||
|
|
; ebp = vertex 2 pointer
|
||
|
|
;
|
||
|
|
RawTriangle_PII_RGB_888 proc
|
||
|
|
SETUP_PI
|
||
|
|
jl reversed
|
||
|
|
mov g_divisor,eax
|
||
|
|
|
||
|
|
PARAM_PI_DIRN comp[C_R*4],work.pr,f
|
||
|
|
PARAM_PI_DIRN comp[C_G*4],work.pg,f
|
||
|
|
PARAM_PI_DIRN comp[C_B*4],work.pb,f
|
||
|
|
|
||
|
|
; Load up registers for first time around inner loop
|
||
|
|
;
|
||
|
|
mov esi,work.main.i
|
||
|
|
|
||
|
|
TRAPEZOID_PII_RGB_888 top,f
|
||
|
|
TRAPEZOID_PII_RGB_888 bot,f
|
||
|
|
quit: ret
|
||
|
|
|
||
|
|
; Scan backwards
|
||
|
|
;
|
||
|
|
reversed:
|
||
|
|
neg eax
|
||
|
|
mov g_divisor,eax
|
||
|
|
|
||
|
|
PARAM_PI_DIRN comp[C_R*4],work.pr,b
|
||
|
|
PARAM_PI_DIRN comp[C_G*4],work.pg,b
|
||
|
|
PARAM_PI_DIRN comp[C_B*4],work.pb,b
|
||
|
|
|
||
|
|
; Load up registers for first time around inner loop
|
||
|
|
;
|
||
|
|
mov esi,work.main.i
|
||
|
|
|
||
|
|
TRAPEZOID_PII_RGB_888 top,b
|
||
|
|
TRAPEZOID_PII_RGB_888 bot,b
|
||
|
|
ret
|
||
|
|
|
||
|
|
SHOW_CODESIZE <RawTriangle_PII_RGB_888>,<%($-_setup_start)>
|
||
|
|
RawTriangle_PII_RGB_888 endp
|
||
|
|
endif
|
||
|
|
|
||
|
|
end
|