Basic graphics routines in separate file and optimizations

gr_basics.asm

@@ -0,0 +1,224 @@
+.IF *>0 ;this is a trick that prevents compiling this file alone
+
+; Basic hardware-dependent graphics routines.
+
+; -----------------------------------------
+.proc unPlot
+; plots a point and saves the plotted byte, reverts the previous plot.
+; -----------------------------------------
+    ldx #0 ; only one pixel
+unPlotAfterX
+    stx WhichUnPlot
+
+    ; first remake the oldie
+    lda oldplotL,x
+    sta oldplot
+    lda oldplotH,x
+    sta oldplot+1
+
+    lda oldply,x
+    tay
+    lda oldora,x
+    sta (oldplot),y
+
+
+    ; is it not out of the screen ????
+    cpw ydraw #screenheight
+    jcc CheckX
+    mwa #0 ydraw
+CheckX
+    cpw xdraw #screenwidth
+    jcs EndOfUnPlot
+MakeUnPlot
+    ; let's count coordinates taken from xdraw and ydraw
+    ;xbyte = xbyte/8
+    lda xdraw+1
+    lsr
+    lda xdraw
+    ror ;just one bit over 256. Max screenwidth = 512!!!
+    lsr
+    lsr
+;---
+    tay
+    ldx WhichUnPlot
+	tya
+    sta oldply,x
+
+    ldx ydraw
+    lda linetableL,x
+    sta xbyte
+    sta oldplot
+    lda linetableH,x
+    sta xbyte+1
+    sta oldplot+1
+
+    lda xdraw
+    and #$7
+    tax
+
+    lda color
+    bne ClearUnPlot
+
+    ;plotting here
+    lda (xbyte),y
+    sta OldOraTemp
+    ora bittable,x
+    sta (xbyte),y
+    bne ContinueUnPlot ; allways <>0
+ClearUnPlot
+    lda (xbyte),y
+    sta OldOraTemp
+    and bittable2,x
+    sta (xbyte),y
+ContinueUnPlot
+    ldx WhichUnPlot
+    lda OldOraTemp
+    sta oldora,x
+    lda oldplot
+    sta oldplotL,x
+    lda oldplot+1
+    sta oldplotH,x
+    ; and now we must solve the problem of several plots
+    ; in one byte
+    ldx #4
+    ldy WhichUnPlot
+LetsCheckOverlapping
+    cpx WhichUnPlot
+    beq SkipThisPlot
+    lda oldplotL,x
+    cmp oldplotL,y
+    bne NotTheSamePlot
+    lda oldplotH,x
+    cmp oldplotH,y
+    bne NotTheSamePlot
+    lda oldply,x
+    cmp oldply,y
+    bne NotTheSamePlot
+    ; the pixel is in the same byte so let's take correct contents
+    lda oldora,x
+    sta oldora,y
+NotTheSamePlot
+SkipThisPlot
+    dex
+    bpl LetsCheckOverlapping
+EndOfUnPlot
+    rts
+.endp
+
+; -----------------------------------------
+.proc plot  ;plot (xdraw, ydraw, color)
+; color == 1 --> put pixel
+; color == 0 --> erase pixel
+; this is one of the most important routines in the whole
+; game. If you are going to speed up the game, start with
+; plot - it is used by every single effect starting from explosions
+; through line drawing and small text output!!!
+; 
+; Optimized by 0xF (Fox) THXXXX!!!
+
+; -----------------------------------------
+    ; is it not over the screen ???
+    cpw ydraw #(screenheight+1); changed for one additional line. cpw ydraw #(screenheight-1)
+    bcs unPlot.EndOfUnPlot ;nearest RTS
+CheckX02
+    cpw xdraw #screenwidth
+    bcs EndOfPlot 
+MakePlot
+    ; let's calculate coordinates from xdraw and ydraw
+
+    ;xbyte = xbyte/8
+    lda xdraw+1
+    lsr
+    lda xdraw
+    ror ;just one bit over 256. Max screenwidth = 512!!!
+    lsr
+    lsr
+    sta xbyte
+    ;---
+    ldx ydraw
+    ldy linetableL,x
+    lda linetableH,x
+    sta xbyte+1
+
+    lda xdraw
+    and #$7
+    tax
+    lda color
+    bne ClearPlot
+
+    lda (xbyte),y
+    ora bittable,x
+    sta (xbyte),y
+EndOfPlot
+    rts
+ClearPlot
+    lda (xbyte),y
+    and bittable2,x
+    sta (xbyte),y
+    rts
+.endp
+
+; -----------------------------------------
+.proc point_plot
+; -----------------------------------------
+    ; checks state of the pixel (coordinates in xdraw and ydraw)
+    ; result is in A (zero or appropriate bit is set)
+
+    ; let's calculate coordinates from xdraw and ydraw
+
+    ;xbyte = xbyte/8
+    lda xdraw+1
+    lsr
+    lda xdraw
+    ror ;just one bit over 256. Max screenwidht = 512!!!
+    lsr
+    lsr
+    sta xbyte
+    ;---
+    ldx ydraw
+    ldy linetableL,x
+    lda linetableH,x
+    sta xbyte+1
+
+    lda xdraw
+    and #$7
+    tax
+
+    lda (xbyte),y
+    eor #$ff
+    and bittable,x
+    rts
+.endp
+
+;--------------------------------------------------
+.proc ClearScreen
+;--------------------------------------------------
+    mwa #display temp
+    ldy #0
+@     lda #$ff
+      sta (temp),y
+      inw temp
+      cpw temp #display+screenheight*screenBytes+1
+    bne @-
+   rts 
+.endp
+
+;--------------------------------------------------
+.proc GenerateLineTable
+
+    mwa #display temp
+    mwa #linetableL temp2
+    mwa #linetableH modify
+    ldy #0
+@     lda temp
+      sta (temp2),y
+      lda temp+1
+      sta (modify),y
+      adw temp #40
+      iny
+      cpy #screenheight+1
+    bne @-
+	rts
+.endp
+
+.ENDIF

grafproc.asm

@@ -473,19 +473,6 @@ endcircleloop
     RTS
 .endp
 
-;--------------------------------------------------
-.proc ClearScreen
-;--------------------------------------------------
-    mwa #display temp
-    ldy #0
-@     lda #$ff
-      sta (temp),y
-      inw temp
-      cpw temp #display+screenheight*screenBytes+1
-    bne @-
-   rts 
-.endp
-
 ;-------------------------------*------------------
 .proc placetanks
 ;--------------------------------------------------
@@ -1643,195 +1630,10 @@ NotHigher
 	rts
 .endp
 
-; -----------------------------------------
+;---------------------------------------------------
-.proc unPlot
+    icl 'gr_basics.asm'
-; plots a point and saves the plotted byte, reverts the previous plot.
+;---------------------------------------------------
-; -----------------------------------------
-    ldx #0 ; only one pixel
-unPlotAfterX
-    stx WhichUnPlot
 
-    ; first remake the oldie
-    lda oldplotL,x
-    sta oldplot
-    lda oldplotH,x
-    sta oldplot+1
-
-    lda oldply,x
-    tay
-    lda oldora,x
-    sta (oldplot),y
-
-
-    ; is it not out of the screen ????
-    cpw ydraw #screenheight
-    jcc CheckX
-    mwa #0 ydraw
-CheckX
-    cpw xdraw #screenwidth
-    jcs EndOfUnPlot
-MakeUnPlot
-    ; let's count coordinates taken from xdraw and ydraw
-    mwa xdraw xbyte
-
-    lda xbyte
-    and #$7
-    sta ybit
-
-    lsrw xbyte
-    rorw xbyte
-    rorw xbyte
-;---
-    ldy xbyte
-
-    ldx WhichUnPlot
-    tya
-    sta oldply,x
-
-
-    ldx ydraw
-    lda linetableL,x
-    sta xbyte
-    sta oldplot
-    lda linetableH,x
-    sta xbyte+1
-    sta oldplot+1
-    ldx ybit
-
-
-    lda color
-    bne ClearUnPlot
-
-    ;plotting here
-    lda (xbyte),y
-    sta OldOraTemp
-    ora bittable,x
-    sta (xbyte),y
-    jmp ContinueUnPlot
-ClearUnPlot
-    lda (xbyte),y
-    sta OldOraTemp
-    and bittable2,x
-    sta (xbyte),y
-ContinueUnPlot
-    ldx WhichUnPlot
-    lda OldOraTemp
-    sta oldora,x
-    lda oldplot
-    sta oldplotL,x
-    lda oldplot+1
-    sta oldplotH,x
-    ; and now we must solve the problem of several plots
-    ; in one byte
-    ldx #4
-    ldy WhichUnPlot
-LetsCheckOverlapping
-    cpx WhichUnPlot
-    beq SkipThisPlot
-    lda oldplotL,x
-    cmp oldplotL,y
-    bne NotTheSamePlot
-    lda oldplotH,x
-    cmp oldplotH,y
-    bne NotTheSamePlot
-    lda oldply,x
-    cmp oldply,y
-    bne NotTheSamePlot
-    ; the pixel is in the same byte so let's take correct contents
-    lda oldora,x
-    sta oldora,y
-NotTheSamePlot
-SkipThisPlot
-    dex
-    bpl LetsCheckOverlapping
-EndOfUnPlot
-    rts
-.endp
-
-; -----------------------------------------
-.proc plot  ;plot (xdraw, ydraw, color)
-; color == 1 --> put pixel
-; color == 0 --> erase pixel
-; this is one of the most important routines in the whole
-; game. If you are going to speed up the game, start with
-; plot - it is used by every single effect starting from explosions
-; through line drawing and small text output!!!
-; 
-; Optimized by 0xF (Fox) THXXXX!!!
-
-; -----------------------------------------
-    ; is it not over the screen ???
-    cpw ydraw #(screenheight+1); changed for one additional line. cpw ydraw #(screenheight-1)
-    bcs unPlot.EndOfUnPlot ;nearest RTS
-CheckX02
-    cpw xdraw #screenwidth
-    bcs EndOfPlot 
-MakePlot
-    ; let's calculate coordinates from xdraw and ydraw
-
-    ;xbyte = xbyte/8
-    lda xdraw+1
-    lsr
-    lda xdraw
-    ror ;just one bit over 256. Max screenwidth = 512!!!
-    lsr
-    lsr
-    sta xbyte
-    ;---
-    ldx ydraw
-    ldy linetableL,x
-    lda linetableH,x
-    sta xbyte+1
-
-    lda xdraw
-    and #$7
-    tax
-    lda color
-    bne ClearPlot
-
-    lda (xbyte),y
-    ora bittable,x
-    sta (xbyte),y
-EndOfPlot
-    rts
-ClearPlot
-    lda (xbyte),y
-    and bittable2,x
-    sta (xbyte),y
-    rts
-.endp
-
-; -----------------------------------------
-.proc point_plot
-; -----------------------------------------
-    ; checks state of the pixel (coordinates in xdraw and ydraw)
-    ; result is in A (zero or appropriate bit is set)
-
-    ; let's calculate coordinates from xdraw and ydraw
-
-    ;xbyte = xbyte/8
-    lda xdraw+1
-    lsr
-    lda xdraw
-    ror ;just one bit over 256. Max screenwidht = 512!!!
-    lsr
-    lsr
-    sta xbyte
-    ;---
-    ldx ydraw
-    ldy linetableL,x
-    lda linetableH,x
-    sta xbyte+1
-
-    lda xdraw
-    and #$7
-    tax
-
-    lda (xbyte),y
-    eor #$ff
-    and bittable,x
-    rts
-.endp
 ;--------------------------------------------------
 .proc TypeChar
 ; puts char on the graphics screen

scorch.asm

@@ -322,18 +322,7 @@ no5200splash
 	jsr SelectNextGradient.NotWind
 
     ; generate linetables
-    mwa #display temp
+	jsr GenerateLineTable
-    mwa #linetableL temp2
-    mwa #linetableH modify
-    ldy #0
-@     lda temp
-      sta (temp2),y
-      lda temp+1
-      sta (modify),y
-      adw temp #40
-      iny
-      cpy #screenheight+1
-    bne @-
 
     .IF TARGET = 800