pixelcore.pas

传奇源代码的delphi版本

      mov eax,[TheSurfaceDesc.lpitch]    // width of surface
      mul [y2]            // multiply with end-point y
      add esi,eax         // add to surface start pointer
      mov ebx,[x2]        // add end-point x position
      imul ebx,3
      add esi,ebx         // esi = starting position of first pixel
      mov eax,[x2]
      mov ebx,[x1]        // set initial values *}
      mov ecx,[y2]
      mov edx,[y1]        // line from (eax,ecx) to (ebx,edx) => (x2,y2) to (x1,y1) *}
      jmp @continue
      @rightOk:
      mov eax,[TheSurfaceDesc.lpitch]    // width of surface
      mul [y1]            // multiply with start-point y
      add esi,eax         // add to surface start pointer
      mov ebx,[x1]        // add start-point x position
      imul ebx,3
      add esi,ebx         // esi = starting position of first pixel
      mov eax,[x1]
      mov ebx,[x2]        // set initial values *}
      mov ecx,[y1]
      mov edx,[y2]        // line from (eax,ecx) to (ebx,edx) => (x1,y1) to (x2,y2) *}
      @continue:
      sub ebx,eax         // ebx = deltaX
      mov eax,[color]     // eax = color
      push ebp            // save ebp to abuse it
      mov ebp,[TheSurfaceDesc.lpitch]    // ebp = pitch
      sub edx,ecx         // edx = deltaY
      js  @RightUp        // draw line right up
      cmp ebx,edx         // test gradient, below 1 or not
      jl  @RightDownSteep // line right-down-ward and steep
      mov ecx,ebx         // prepare spill-element ecx
      shr ecx,1
      neg ecx
      add ecx,edx         // ecx = -(deltaX)/2 + deltaY
      mov edi,ebx         // prepare counter edi (equal to deltaX)
      dec edi             // prevention of single dot crash
      mov ds:[esi],ax     // set first pixel
      ror eax,16
      mov ds:[esi+2],al
      @loopRDSh:          // loop for Right Down Shallow
      or  ecx,ecx         // check spill-element
      js  @skipRDSh       // if signed skip
      sub ecx,ebx         // reset spill-element
      add esi,ebp         // calculate vertical step
      @skipRDSh:
      add ecx,edx         // increase spill-element by deltaY
      add esi,3           // mov pixel onward
      mov ds:[esi],ax     // set pixel
      ror eax,16
      mov ds:[esi+2],al
      dec edi             // decrement counter
      jns @loopRDSh       // loop until signed
      jmp @ende           // terminate
      @RightDownSteep:
      mov ecx,edx         // prepare spill-element CX
      shr ecx,1
      neg ecx
      add ecx,ebx         // ecx = -(deltaY)/2 + deltaX
      mov edi,edx         // prepare counter edi (equal to deltaY)
      dec edi             // prevention of single dot crash
      mov ds:[esi],ax     // set pixel
      ror eax,16
      mov ds:[esi+2],al
      @loopRDSt:          // loop for Right Down Steep
      or  ecx,ecx         // check spill-element
      js  @skipRDSt       // if signed skip
      sub ecx,edx         // reset spill-element
      add esi,3           // mov pixel onward
      @skipRDSt:
      add ecx,ebx         // increase spill-element by deltaX
      add esi,ebp         // calculate new pixel offset
      mov ds:[esi],ax     // set pixel
      ror eax,16
      mov ds:[esi+2],al
      dec edi             // decrement counter
      jns @loopRDSt       // loop until signed
      jmp @ende           // terminate
      @RightUp:
      neg edx             // reallign DX
      cmp ebx,edx         // test gradient, below 1 or not
      jl  @RightUpSteep   // line right-up-ward and steep
      mov ecx,ebx         // prepare spill-element CX
      shr ecx,1
      neg ecx
      add ecx,edx         // CX = -(deltaX)/2 + deltaY
      mov edi,ebx         // prepare counter edi (equal to deltaX)
      dec edi             // prevention of single dot crash
      mov ds:[esi],ax     // set pixel
      ror eax,16
      mov ds:[esi+2],al
      @loopRUSh:          // loop for Right Up Shallow
      or  ecx,ecx         // check spill-element
      js  @skipRUSh       // if signed skip
      sub ecx,ebx         // reset spill-element
      sub esi,ebp         // calculate vertical step
      @skipRUSh:
      add ecx,edx         // increase spill-element by deltaY
      add esi,3           // next pixel
      mov ds:[esi],ax     // set pixel
      ror eax,16
      mov ds:[esi+2],al
      dec edi             // decrement counter
      jns @loopRUSh       // loop until signed
      jmp @ende           // terminate
      @RightUpSteep:
      mov ecx,edx         // prepare spill-element CX
      shr ecx,1
      neg ecx
      add ecx,ebx         // ecx = -(deltaY)/2 + deltaX
      mov edi,edx         // prepare counter edi (equal to deltaY)
      dec edi             // prevention of single dot crash
      mov ds:[esi],ax     // set pixel
      ror eax,16
      mov ds:[esi+2],al
      @loopRUSt:          // loop for Right Up Steep
      or  ecx,ecx         // check spill-element
      js  @skipRUSt       // if signed skip
      sub ecx,edx         // reset spill-element
      add esi,3           // vertical step
      @skipRUSt:
      add ecx,ebx         // increase spill-element by deltaX
      sub esi,ebp         // calculate new pixel offset
      mov ds:[esi],ax     // set pixel
      ror eax,16
      mov ds:[esi+2],al
      dec edi             // decrement counter
      jns @loopRUSt       // loop until signed
      @ende:
      pop ebp
      popa
      pop esi
      pop edi
      pop ebp
      pop ebx
   end;
end;

procedure Line32(x1,y1,x2,y2,color : integer);
{ no clipping is performed }
begin
   asm
      push ebx
      push ebp
      push edi
      push esi
      pusha
      mov esi,TheSurfaceDesc.lpSurface
      mov eax,[x1]        // eax = x1
      mov ebx,[x2]        // ebx = x2
      sub ebx,eax         // ebx = x2-x1
      jns @rightOk        // if negative, then swap start/end point
      mov eax,[TheSurfaceDesc.lpitch]    // width of surface
      mul [y2]            // multiply with end-point y
      add esi,eax         // add to surface start pointer
      mov ebx,[x2]        // add end-point x position
      shl ebx,2
      add esi,ebx         // esi = starting position of first pixel
      mov eax,[x2]
      mov ebx,[x1]        // set initial values *}
      mov ecx,[y2]
      mov edx,[y1]        // line from (eax,ecx) to (ebx,edx) => (x2,y2) to (x1,y1) *}
      jmp @continue
      @rightOk:
      mov eax,[TheSurfaceDesc.lpitch]    // width of surface
      mul [y1]            // multiply with start-point y
      add esi,eax         // add to surface start pointer
      mov ebx,[x1]        // add start-point x position
      shl ebx,2
      add esi,ebx         // esi = starting position of first pixel
      mov eax,[x1]
      mov ebx,[x2]        // set initial values *}
      mov ecx,[y1]
      mov edx,[y2]        // line from (eax,ecx) to (ebx,edx) => (x1,y1) to (x2,y2) *}
      @continue:
      sub ebx,eax         // ebx = deltaX
      mov eax,[color]     // eax = color
      push ebp            // save ebp to abuse it
      mov ebp,[TheSurfaceDesc.lpitch]    // ebp = pitch
      sub edx,ecx         // edx = deltaY
      js  @RightUp        // draw line right up
      cmp ebx,edx         // test gradient, below 1 or not
      jl  @RightDownSteep // line right-down-ward and steep
      mov ecx,ebx         // prepare spill-element ecx
      shr ecx,1
      neg ecx
      add ecx,edx         // ecx = -(deltaX)/2 + deltaY
      mov edi,ebx         // prepare counter edi (equal to deltaX)
      dec edi             // prevention of single dot crash
      mov ds:[esi],eax    // set pixel
      @loopRDSh:          // loop for Right Down Shallow
      or  ecx,ecx         // check spill-element
      js  @skipRDSh       // if signed skip
      sub ecx,ebx         // reset spill-element
      add esi,ebp         // calculate vertical step
      @skipRDSh:
      add ecx,edx         // increase spill-element by deltaY
      add esi,4           // mov pixel onward
      mov ds:[esi],eax    // set pixel
      dec edi             // decrement counter
      jns @loopRDSh       // loop until signed
      jmp @ende           // terminate
      @RightDownSteep:
      mov ecx,edx         // prepare spill-element CX
      shr ecx,1
      neg ecx
      add ecx,ebx         // ecx = -(deltaY)/2 + deltaX
      mov edi,edx         // prepare counter edi (equal to deltaY)
      dec edi             // prevention of single dot crash
      mov ds:[esi],eax    // set pixel
      @loopRDSt:          // loop for Right Down Steep
      or  ecx,ecx         // check spill-element
      js  @skipRDSt       // if signed skip
      sub ecx,edx         // reset spill-element
      add esi,4           // mov pixel onward
      @skipRDSt:
      add ecx,ebx         // increase spill-element by deltaX
      add esi,ebp         // calculate new pixel offset
      mov ds:[esi],eax     // set pixel
      dec edi             // decrement counter
      jns @loopRDSt       // loop until signed
      jmp @ende           // terminate
      @RightUp:
      neg edx             // reallign DX
      cmp ebx,edx         // test gradient, below 1 or not
      jl  @RightUpSteep   // line right-up-ward and steep
      mov ecx,ebx         // prepare spill-element CX
      shr ecx,1
      neg ecx
      add ecx,edx         // CX = -(deltaX)/2 + deltaY
      mov edi,ebx         // prepare counter edi (equal to deltaX)
      dec edi             // prevention of single dot crash
      mov ds:[esi],eax    // set first pixel
      @loopRUSh:          // loop for Right Up Shallow
      or  ecx,ecx         // check spill-element
      js  @skipRUSh       // if signed skip
      sub ecx,ebx         // reset spill-element
      sub esi,ebp         // calculate vertical step
      @skipRUSh:
      add ecx,edx         // increase spill-element by deltaY
      add esi,4           // next pixel
      mov ds:[esi],eax    // set first pixel
      dec edi             // decrement counter
      jns @loopRUSh       // loop until signed
      jmp @ende           // terminate
      @RightUpSteep:
      mov ecx,edx         // prepare spill-element CX
      shr ecx,1
      neg ecx
      add ecx,ebx         // ecx = -(deltaY)/2 + deltaX
      mov edi,edx         // prepare counter edi (equal to deltaY)
      dec edi             // prevention of single dot crash
      mov ds:[esi],eax    // set first pixel
      @loopRUSt:          // loop for Right Up Steep
      or  ecx,ecx         // check spill-element
      js  @skipRUSt       // if signed skip
      sub ecx,edx         // reset spill-element
      add esi,4           // vertical step
      @skipRUSt:
      add ecx,ebx         // increase spill-element by deltaX
      sub esi,ebp         // calculate new pixel offset
      mov ds:[esi],eax    // set current pixel
      dec edi             // decrement counter
      jns @loopRUSt       // loop until signed
      @ende:
      pop ebp
      popa
      pop esi
      pop edi
      pop ebp
      pop ebx
   end;
end;

end.