examples: new sprite animation demo

examples/animate.pas

@@ -0,0 +1,136 @@
+program animate;
+uses sprites;
+
+type PictData = record
+		magic,mode:integer;
+		palette: array [0..15] of integer;
+		pixeldata: array [0..31999] of integer;
+	end;
+
+     Sprite = record
+     	x,y:integer;
+     	oldX,oldY:integer;
+     	xdelta,ydelta:integer;
+     	curFrame:integer;
+     	frameCount:integer;
+     	frameTime:integer;
+     	frameLeft:integer;
+     	changed:boolean;
+     	frame:array [0..3] of SpritePixels;
+    end;
+
+var pic:PictData;
+    filename:string;
+    infile:file;
+    ch:char;
+    stickMan:Sprite;
+
+procedure WaitVSync; external;
+
+procedure loadPalette(var pic:PictData);
+var i:integer;
+begin
+	for i := 0 to 15 do
+		setpalette(i, pic.palette[i]);
+end;
+
+procedure showPic(var pic:PictData);
+begin
+	PutScreen(pic.pixeldata);
+end;
+
+procedure loadSpriteFrame(var aSprite:Sprite;spriteIndex:integer;
+		var sheetFile:file;sheetIndex:integer);
+begin
+	seek(sheetFile, 8 + sheetIndex * 512);
+	read(sheetFile, aSprite.frame[spriteIndex]);
+	if aSprite.frameCount <= spriteIndex then
+		aSprite.frameCount := spriteIndex + 1;
+
+	aSprite.curFrame := 0;
+	writeln('loaded sprite frame ', spriteIndex, ' from ', sheetIndex);
+end;
+
+procedure animateSprite(var aSprite:Sprite);
+var frameIndex:integer;
+    frameTime,frameLeft:integer;
+    ydelta:integer;
+    oldX,oldY:integer;
+begin
+	ydelta := aSprite.ydelta;
+	frameIndex := aSprite.curFrame;
+	frameTime := aSprite.frameTime;
+	frameLeft := aSprite.frameLeft;
+	oldX := aSprite.x; oldY := aSprite.y;
+	aSprite.oldX := oldX; aSprite.oldY := oldY;
+
+	frameLeft := frameLeft - 1;
+	if frameLeft <= 0 then
+	begin
+		frameIndex := frameIndex + 1;
+		frameLeft := aSPrite.frameTime;
+		aSprite.frameLeft := frameLeft;
+		aSprite.curFrame := frameIndex;
+		if frameIndex >= aSprite.frameCount then
+			aSprite.curFrame := 0;
+
+		aSprite.frameLeft := frameLeft;
+
+		aSprite.x := aSprite.x + aSprite.xdelta;
+		aSprite.y := aSprite.y + aSprite.ydelta;
+
+		if aSprite.x > 608 then aSprite.x := 0;
+	end;
+	aSprite.frameLeft := frameLeft;
+end;
+
+procedure animLoop;
+var i:integer;
+    oldX,oldY:integer;
+begin
+	stickMan.x := 0;
+	stickMan.y := 310;
+	stickMan.frameTime := 6;
+	stickMan.frameLeft := stickMan.frameTime;
+	stickMan.curFrame := 0;
+	stickMan.xdelta := 2;
+	stickMan.ydelta := 0;
+
+	oldX := stickMan.x;
+	oldY := stickMan.y;
+
+	while not ConAvail do
+	begin
+		oldX := stickMan.x;
+		oldY := stickMan.y;
+		
+		PutSprite(oldX, oldY, stickMan.frame[stickMan.curFrame]);
+
+		animateSprite(stickMan);
+		Delay(10);
+		WaitVSync;
+
+		UndrawSprite(oldX, oldY, pic.pixeldata);
+	end;
+end;
+
+begin
+	filename := 'grey.pict';
+	open(infile, filename, ModeReadonly);
+	read(infile, pic);
+	close(infile);
+
+	writeln('magic: ', pic.magic, ' mode:', pic.mode);
+
+	loadPalette(pic);
+	showPic(pic);
+
+	open(infile, 'Walking.sprt', ModeReadOnly);
+	loadSpriteFrame(stickMan, 0, infile, 0);
+	loadSpriteFrame(stickMan, 1, infile, 1);
+	loadSpriteFrame(stickMan, 2, infile, 2);
+	loadSpriteFrame(stickMan, 3, infile, 3);
+	close(infile);
+
+	animLoop;
+end.

examples/sprites.inc

@@ -1,4 +1,4 @@
-type SpritePixels = array[0..31] of integer;
+type SpritePixels = array[0..128] of integer;
 type BackgroundPixels = array[0..31999] of integer;
 
 procedure PutSprite(x,y:integer; var sprite: SpritePixels); external;

examples/sprites.s

@@ -1,4 +1,5 @@
-	.EQU SPRITE_HEIGHT 16
+	.EQU SPRITE_HEIGHT 32	; height in lines
+	.EQU SPRITE_STRIPES 4	; width in words i.e. 8-pixel stripes
 
         .EQU WORDS_PER_LINE 80
         .EQU FB_RA      $900
@@ -65,7 +66,8 @@ CALC_VMEM_ADDR:
 	.EQU PS_Y		16
 	.EQU PS_SHIFT_C		20
 	.EQU PS_SPILL		24
-	.EQU PS_FS 28
+	.EQU PS_STRIPE_C	28
+	.EQU PS_FS 32
 PUTSPRITE:
 	FPADJ -PS_FS
 	STORE PS_SPRITE_DATA
@@ -160,10 +162,14 @@ PS_LOOP2_X:
 	STOREI			; store result into i/o reg
 	DROP
 
-	;
+	; set counter for remaining stripes
-	; process spilled bits and right half of sprite data
+	LOADC SPRITE_STRIPES - 1
-	;
+	STORE PS_STRIPE_C
 
+	;
+	; process spilled bits and next vertical stripe of sprite data
+	;
+PS_NEXT_STRIPE:
 	; put spill bits on stack for later
 	LOAD PS_SPILL
 
@@ -177,6 +183,8 @@ PS_LOOP2_X:
 	LOADC 0
 	STORE PS_SPILL
 
+	; last spill bits are on ToS now
+
 	; shift pixel data to right
 	LOAD PS_SHIFT_C		; load shift count
 PS_LOOP3:			; test it for zero
@@ -231,7 +239,13 @@ PS_LOOP3_X:
 	STOREI
 	DROP
 
-	; write spilled bits into next vmem word
+	LOAD PS_STRIPE_C	; decrement stripe count
+	DEC 1
+	DUP
+	STORE PS_STRIPE_C
+	CBRANCH.NZ PS_NEXT_STRIPE ; if non-zero, next stripe
+
+	; write spilled bits of the last stripe into next vmem word
 	LOAD PS_SPILL		; get spill bits
 	DUP
 	LOADCP CALC_MASK	; calculate sprite mask for spill bits
@@ -274,7 +288,8 @@ PS_L_XT:
 	.EQU UD_S_BGDATA 12
 	.EQU UD_S_OFFSET 16
 	.EQU UD_S_BGORIG 20
-	.EQU UD_S_FS 24
+	.EQU UD_STRIPE_C 24
+	.EQU UD_S_FS 28
 UNDRAWSPRITE:
 	FPADJ -UD_S_FS
 	STORE UD_S_BGORIG
@@ -318,25 +333,35 @@ UD_S_L1:
 	STOREI
 	; reuse addr from STOREI
 
-	; load 2nd word of background data	
+	LOADC SPRITE_STRIPES - 1 ; set remaining stripe count
+	STORE UD_STRIPE_C
+
+UD_NEXT_STRIPE:
+	; load next word of background data	
 	LOAD UD_S_BGDATA
 	INC 4
 	DUP
 	STORE UD_S_BGDATA
 	LOADI
 	STOREI ; and write it to vmem
-	DROP
+	; reuse addr from STOREI
 
-	; if pixel shift is zero, no 3rd word
+	LOAD UD_STRIPE_C	; decrease remaining stripe count
+	DEC 1
+	DUP
+	STORE UD_STRIPE_C
+	CBRANCH.NZ UD_NEXT_STRIPE ; if non-zero, next stripe
+
+	DROP ; remove addr from STOREI
+
+	; if pixel shift is zero, no spill word
 	LOAD UD_S_PXS
 	CBRANCH.Z UD_S_L2
 
-	; load 3rd word of background data
+	; load next word of background data
 	LOADCP FB_IO
 	LOAD UD_S_BGDATA
 	INC 4
-	DUP
-	STORE UD_S_BGDATA
 	LOADI
 	STOREI ; and write it to vmem
 	DROP

utils/png2pict.py

@@ -2,6 +2,9 @@
 import sys
 import png
 
+sprite_width = 32
+sprite_height = 32
+
 def process_pixdata(outfile, pixdata, frameindex = 0, pix_w=640, pix_h=400):
 
     pixmask = 15
@@ -72,22 +75,20 @@ def write_pict_file(width, height, px, metadata, outfile):
 
 
 def write_sprite_file(width, height, px, metadata, outfile):
-    sprite_height=16
-
     print("processing as SPRT file with {} sprites...".format(height//sprite_height))
-    if width != 16:
+    if width != sprite_width:
-        print("width must be 16, aborting")
+        print("width must be {}, aborting".format(sprite_width))
         sys.exit(1)
     pixdata = list(px)
     palette = metadata['palette']
 
     if len(palette) != 16:
-        print("palette must have 16 colors, aborting")
+        print("palette must have 16 colors instead of {}, aborting".format(len(palette)))
         sys.exit(0)
 
     with open(outfile,'wb') as f:
         write_sprite_header(f)
-        process_pixdata(f, pixdata, pix_w=16, pix_h=height)
+        process_pixdata(f, pixdata, pix_w=sprite_width, pix_h=height)
 
 
 if __name__ == '__main__':
@@ -103,8 +104,8 @@ if __name__ == '__main__':
     width, height, px, metadata = p
     if width == 640:
         write_pict_file(width, height, px, metadata, outfile)
-    elif width == 16:
+    elif width == sprite_width:
         write_sprite_file(width, height, px, metadata, outfile)
     else:
-        print("Can't handle this file, need a width of\n640 or 16 pixels with 16 color palette.")
+        print("Can't handle this file, need a width of\n640 or {} pixels with 16 color palette.".format(sprite_width))