Buzz #13 12 февраля 1998

Ассемблер     Программирование

Ассемблер - Процедуры : Stretch texture engine, Texture mapping engine, Texture mapping + gourauds hading engine, Gouraudmapping engine for Z80.

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   Мы продолжаем печатать ultra faaaaast алгоритмы by  Exploder/
MegaCode/Extreme.

 +------------------------------------------------------------+
 |           - Stretch texture engine for Z80 CPU -           |
 |             - last n'joyment date: 11-JUL-97 -             |
 +------------------------------------------------------------+

And now...
Ultra faaaaast stretch texture algorythm 

ver_1:
        POP     HL              ; Read XY shifts 
        ADD     HL,BC           ; Increase YX pos in texture
        LD      A,(HL)          ; Read texel from texture
        LD      (DE),A          ; Write texel to chunky buffer
        INC     E               ;

About 39 takts of CPU power

Really needed:
        SP = Pointer to shifts-tab
        BC = YX-increase
        DE = Pointer to destination chunky buffer

ver_2:
        LD      HL,#0000        ; XY shifts data 
        ADD     HL,BC           ; Increase YX pos in texture
        LD      D,(HL)          ; Read texel from texture
        LD      HL,#0000        ; XY shifts data 
        ADD     HL,BC           ; Increase YX pos in texture
        LD      E,(HL)          ; Read texel from texture
        PUSH    DE              ; Write 2texels to chunky buffer

About 67 takts of CPU power

Really needed:
        BC = YX-increase
        SP = Pointer to destination chunky buffer

ver_3: with light map mix
        POP     HL              ; Read XY shifts 
        ADD     HL,BC           ; Increase YX pos in texture
        LD      L,(HL)          ; Read texel from texture
        LD      H,(IX+#00)      ; Read light tab pointer
        LD      (DE),A          ; Write texel to chunky buffer
        INC     E               ;

About 58 takts of CPU power

Really needed:
        SP = Pointer to shifts-tab
        BC = YX-increase
        DE = Pointer to destination chunky buffer
        IX = Pointer to light tab

ver_4: with light map mix
        LD      HL,#0000        ; XY shifts data 
        ADD     HL,BC           ; Increase YX pos in texture
        LD      L,(HL)          ; Read texel from texture
        LD      H,#00           ; Light pointer data
        LD      D,(HL)          ; Read mixed texel
        LD      HL,#0000        ; XY shifts data 
        ADD     HL,BC           ; Increase YX pos in texture
        LD      L,(HL)          ; Read texel from texture
        LD      H,#00           ; Light pointer data
        LD      E,(HL)          ; Read mixed texel
        PUSH    DE              ; Write 2texels to chunky buffer

About 93 takts of CPU power

Really needed:
        BC = YX-increase
        SP = Pointer to destination chunky buffer

   Is the fastest stretch texture code for Z80. Nothing else.

 +------------------------------------------------------------+
 |            - Texturemapping engine for Z80 CPU  -          |
 |              - last n'joyment date: 25-NOV-97 -            |
 +------------------------------------------------------------+

And now...
Ultra faaaaast texturemapped algorythm 

        LD      A,H             ;
        ADD     HL,BC           ; Increase Y-pos in texture
        EXX                     ;
        LD      D,A             ; Set Y-pos
        LD      E,H             ; Set X-pos
        LD      A,(DE)          ; Get texel from texture
        ADD     HL,BC           ; Increase X-pos in texture
        EXX                     ;
        LD      (DE),A          ; Write texel to chunky buffer
        INC     E               ; 

About 60 takts of CPU power

Really needed:
        HL = Y-position on texture
        BC = Y-increase
        DE = Pointer to destination chunky buffer
        HL'= X-position on texture
        BC'= X-increase


   Is the fastest texturemapping code for Z80. Nothing else.

 +------------------------------------------------------------+
 |   - Texturemapping + gouraudshading engine for Z80 CPU -   |
 |             - last n'joyment date: 06-DEC-97 -             |
 +------------------------------------------------------------+

And now...
Ultra faaaaast tmap+gouraudshading algorythm 

        LD      A,H             ;
        ADD     HL,BC           ; Increase Y-pos in texture
        EXX                     ;
        LD      D,A             ; Set Y-pos
        LD      E,H             ; Set X-pos
        LD      A,(DE)          ; Get texel from texture
        LD      HL,BC           ; Increase X-pos in texture
        LD      E,A             ;
        LD      D,(IX+#00)      ; Get shading pointer
        LD      A,(DE)          ; Get shaded texel
        EXX                     ;
        ADD     IX,DE           ; Increase shading-table pointer
        LD      (IY+#00),A      ; Write shaded texel to buffer

About 113 takts of CPU power

Really needed:
        HL = Y-position on texture
        BC = Y-increase
        IX = Pointer to shading-table
        DE = Shading-increase
        HL'= X-position on texture
        BC'= X-increase
        IY = Pointer to destination chunky buffer

 Is the fastest tmap+gouraudshading code for Z80. Nothing else.

 +------------------------------------------------------------+
 |           - Gouraudmapping engine for Z80 CPU  -           |
 |             - last n'joyment date: 05-DEC-97 -             |
 +------------------------------------------------------------+

And now...
Ultra faaaaast gouraudmapping algorythm 

ver_1: extra fast
        LDI                     ; Write shaded pixel to buffer
        ADD      HL,BC          ; Increase shading-table pointer

About 27 takts of CPU power

ver_2: full correctly
        LD      A,(HL)          ; Read data from shading-table
        LD      (DE),A          ; Write shaded pixel to buffer
        INC     E
        ADD     HL,BC           ; Increase shading-table pointer

About 29 takts of CPU power

Really needed:
        HL = Pointer to shading-table
        BC = Shading-increase
        DE = Pointer to destination chunky buffer

   Is the fastest gouraudmapping code for Z80. Nothing else.

 +----------------------------------------*Exploder/Extreme*--+
 |     - exploder_xtm@usa.net -   - +7 (0922) 29-04-25 -      |
 +-------------------------------------------<ZX128,A1200>----+