; Seven Kingdoms: Ancient Adversaries
;
; Copyright 1997,1998 Enlight Software Ltd.
;
; This program is free software: you can redistribute it and/or modify
; it under the terms of the GNU General Public License as published by
; the Free Software Foundation, either version 2 of the License, or
; (at your option) any later version.
;
; This program is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
; GNU General Public License for more details.
;
; You should have received a copy of the GNU General Public License
; along with this program.  If not, see <http://www.gnu.org/licenses/>.
;

;Filename    : I_EMASK.ASM
;Description : Blt exploration mask of 32x32 to the display surface buffer
; a modified version, 16 mask

INCLUDE IMGFUN.inc

; ------------ Define constant ------------

		PUBLIC IMGexploreMask32x32

MASKCOLOUR	= 0

EAST_BIT_MASK	= 1
CENTRE_BIT_MASK = 2
WEST_BIT_MASK   = 4

NORTH1_MASK_OFFS	= 0
SOUTH1_MASK_OFFS	= 20h
WEST1_MASK_OFFS	= 40h
EAST1_MASK_OFFS	= 60h
NW_MASK_OFFS	= 80h
NE_MASK_OFFS	= 0a0h
SW_MASK_OFFS	= 0c0h
SE_MASK_OFFS	= 0e0h
XNW_MASK_OFFS	= 100h
XNE_MASK_OFFS	= 120h
XSW_MASK_OFFS	= 140h
XSE_MASK_OFFS	= 160h
NORTH2_MASK_OFFS	= 180h
SOUTH2_MASK_OFFS	= 1a0h
WEST2_MASK_OFFS	= 1c0h
EAST2_MASK_OFFS	= 1e0h

		.DATA
; bit 0 = north sqaure, bit 1 = north west square, bit 2 = west square
NW_SQR_DECISION DD XSE_MASK_OFFS, WEST1_MASK_OFFS, XSE_MASK_OFFS, WEST1_MASK_OFFS
		DD NORTH1_MASK_OFFS, NW_MASK_OFFS, NORTH1_MASK_OFFS, -1

; bit 0 = east square, bit 1 = north east square, bit 2 = north square
NE_SQR_DECISION DD XSW_MASK_OFFS, NORTH2_MASK_OFFS, XSW_MASK_OFFS, NORTH2_MASK_OFFS
		DD EAST1_MASK_OFFS, NE_MASK_OFFS, EAST1_MASK_OFFS, -1

; bit 0 = south square, bit 1 = south west square, bit 2 = west square
SW_SQR_DECISION DD XNE_MASK_OFFS, WEST2_MASK_OFFS, XNE_MASK_OFFS, WEST2_MASK_OFFS
		DD SOUTH1_MASK_OFFS, SW_MASK_OFFS, SOUTH1_MASK_OFFS, -1

; bit 0 = east square, bit 1 = south east square, bit 2 = south square
SE_SQR_DECISION DD XNW_MASK_OFFS, SOUTH2_MASK_OFFS, XNW_MASK_OFFS, SOUTH2_MASK_OFFS
		DD EAST2_MASK_OFFS, SE_MASK_OFFS, EAST2_MASK_OFFS, -1

buf_pitch	DD ?

		.CODE


;------------ BEGIN OF MACRO MASKDOT ----------
MASKDOT		MACRO
		LOCAL	@@maskdot1
		SHR	AX,1
		JC	@@maskdot1
		MOV	byte ptr [EDI], MASKCOLOUR
@@maskdot1:
		INC	EDI
		ENDM
;------------ END OF MACRO MASKDOT ----------


;------------ BEGIN OF FUNCTION IMGmask16x16 -----------
IMGmask16x16 PROC
; input :
; EDI = destination
; ESI = maskPtr
		PUSH	EAX
		PUSH	ECX
		PUSH	EDX
		PUSH	ESI
		PUSH	EDI

		MOV	EDX, buf_pitch
		SUB	EDX, 16
		CLD

		MOV	ECX, 16
@@line0:
		LODSW

		MASKDOT
		MASKDOT
		MASKDOT
		MASKDOT

		MASKDOT
		MASKDOT
		MASKDOT
		MASKDOT

		MASKDOT
		MASKDOT
		MASKDOT
		MASKDOT

		MASKDOT
		MASKDOT
		MASKDOT
		MASKDOT

		ADD	EDI, EDX

		DEC	ECX
		JNZ	@@line0

@@line2:	POP	EDI
		POP	ESI
		POP	EDX
		POP	ECX
		POP	EAX
		RET
IMGmask16x16	ENDP
;------------ END OF FUNCTION IMGmask16x16 -----------


;---------- BEGIN OF FUNCTION IMGexploreMask32x32 -------
;
; Smooth the area between explore and unexplored square
;
; Syntax : IMGexploreMask32x32( imageBuf, pitch, x, y, maskPtr, northRow, thisRow, southRow)
;
; char *imageBuf - the pointer to the display surface buffer
; int pitch      - the pitch of the display surface buffer
; int  x,y       - where to put the image on the surface buffer
; char *maskPtr  - pointer of masks, (address of 'EXPLMASK.BIN' is loaded)
; northRow       - explored_flag of adjacent location
;                  bit 0 - north east square (0=unexplored, 1=explored)
;                  bit 1 - north square
;                  bit 2 - north west square
; thisRow        - bit 0 - east square
;                  bit 1 - this square
;                  bit 2 - west square
; southRow       - bit 0 - south east square
;                  bit 1 - south square
;                  bit 2 - south west square
;
;--------------------------------------------------------

IMGexploreMask32x32	PROC imageBuf, pitch, x, y, maskPtr, northRow, thisRow, southRow
		STARTPROC

		MOV	EAX, imageBuf
		MOV	image_buf, EAX
		MOV	EAX, pitch
		MOV	buf_pitch, EAX

		; north west 16x16
@@nw0:		XOR	EBX, EBX
		MOV	EAX, northRow
		AND     AL, CENTRE_BIT_MASK OR WEST_BIT_MASK
		SHR	AL, 1
		MOV	BL, AL
		MOV	EAX, thisRow
		AND	AL, WEST_BIT_MASK
		OR	BL, AL
		CMP	BL,7
		JE	@@ne0

		MOV	EAX, [NW_SQR_DECISION + 4*EBX]
		MOV	ESI, maskPtr
		ADD	ESI, EAX
		CALC_ADDR	EDI, x ,y, pitch
		CALL	IMGmask16x16

		; north east 16x16
@@ne0:		XOR	EBX, EBX
		MOV	EAX, northRow
		AND	AL, CENTRE_BIT_MASK OR EAST_BIT_MASK
		SHL	AL, 1
		MOV	BL, AL
		MOV	EAX, thisRow
		AND	AL, EAST_BIT_MASK
		OR	BL, AL
		CMP	BL, 7
		JE	@@sw0

		MOV	EAX, [NE_SQR_DECISION + 4*EBX]
		MOV	ESI, maskPtr
		ADD	ESI, EAX
		CALC_ADDR_2	EDI, x, y, 16, 0, pitch
		CALL	IMGmask16x16

		; south west 16x16
@@sw0:		XOR	EBX, EBX
		MOV	EAX, southRow
		AND     AL, CENTRE_BIT_MASK OR WEST_BIT_MASK
		SHR	AL, 1
		MOV	BL, AL
		MOV	EAX, thisRow
		AND	AL, WEST_BIT_MASK
		OR	BL, AL
		CMP	BL, 7
		JE	@@se0

		MOV	EAX, [SW_SQR_DECISION + 4*EBX]
		MOV	ESI, maskPtr
		ADD	ESI, EAX
		CALC_ADDR_2	EDI, x, y, 0, 16, pitch
		CALL	IMGmask16x16

		; south east 16x16
@@se0:		XOR	EBX, EBX
		MOV	EAX, southRow
		AND	AL, CENTRE_BIT_MASK OR EAST_BIT_MASK
		SHL	AL, 1
		MOV	BL, AL
		MOV	EAX, thisRow
		AND	AL, EAST_BIT_MASK
		OR	BL, AL
		CMP	BL, 7
		JE	@@end

		MOV	EAX, [SE_SQR_DECISION + 4*EBX]
		MOV	ESI, maskPtr
		ADD	ESI, EAX
		CALC_ADDR_2	EDI, x, y, 16, 16, pitch
		CALL	IMGmask16x16

@@end:		ENDPROC
IMGexploreMask32x32	ENDP
;------------ END OF FUNCTION IMGexploreMask32x32 -------

		END