From 322546a0b16397a3d00e995396bb8030acd60807 Mon Sep 17 00:00:00 2001
From: David Schmenk <dschmenk@sbcglobal.net>
Date: Sat, 28 Dec 2019 08:19:31 -0800
Subject: [PATCH] Add sprite center

---
 src/inc/sprite.plh          |  2 +-
 src/libsrc/apple/sprite.pla | 17 ++++++++++++-----
 src/samplesrc/hgrtest.pla   |  6 +++---
 3 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/src/inc/sprite.plh b/src/inc/sprite.plh
index 4c26f97..da90150 100644
--- a/src/inc/sprite.plh
+++ b/src/inc/sprite.plh
@@ -1,5 +1,5 @@
 import sprite
-    predef spriteCompile(w, h, srcptr)#1
+    predef spriteCompile(w, h, xcenter, ycenter, srcptr)#1
     predef spriteDup(sprtsrc)#1
     predef spriteRead(filestr)#1
     predef spriteSave(filestr, sprtptr)#1
diff --git a/src/libsrc/apple/sprite.pla b/src/libsrc/apple/sprite.pla
index 358a94a..5f60ee1 100644
--- a/src/libsrc/apple/sprite.pla
+++ b/src/libsrc/apple/sprite.pla
@@ -8,6 +8,8 @@ struc t_sprite
     var  s_undery[2]
     var  s_underofst[2]
     byte s_undermap[2]
+    byte s_xcenter
+    byte s_ycenter
     byte s_pitch
     byte s_height
     var  s_size
@@ -121,7 +123,7 @@ def spriteBLTMask(x, y, w, h, srcptr)#0
         srcptr = srcptr + (w + 1) / 2
     next
 end
-export def spriteCompile(w, h, srcptr)#1
+export def spriteCompile(w, h, xcenter, ycenter, srcptr)#1
     var sprtptr, bytewidth, spritesize, i
     
     sprtptr             = heapalloc(t_sprite)
@@ -130,6 +132,8 @@ export def spriteCompile(w, h, srcptr)#1
     spritesize          = bytewidth * h
     sprtptr=>s_size     = spritesize
     sprtptr->s_height   = h
+    sprtptr->s_xcenter  = xcenter
+    sprtptr->s_ycenter  = ycenter
     sprtptr=>s_under[0] = heapalloc(spritesize)
     sprtptr=>s_under[1] = heapalloc(spritesize)
     for i = 0 to 13
@@ -155,6 +159,9 @@ export def spriteDup(sprtsrc)#1
     sprtdup=>s_size     = spritesize
     sprtdup->s_pitch    = sprtsrc->s_pitch 
     sprtdup->s_height   = sprtsrc->s_height
+    sprtdup->s_height   = sprtsrc->s_height
+    sprtdup->s_xcenter  = sprtsrc->s_xcenter
+    sprtdup->s_ycenter  = sprtsrc->s_ycenter
     sprtdup=>s_under[0] = heapalloc(spritesize)
     sprtdup=>s_under[1] = heapalloc(spritesize)
     for i = 0 to 13
@@ -250,14 +257,14 @@ export def spriteUnDrawXor(sprtptr)#0
     hgrXorSrc(sprtptr=>s_underofst[drawpage], sprtptr=>s_undery[drawpage], sprtptr->s_pitch, sprtptr->s_height, sprtptr=>s_map[sprtptr->s_undermap[drawpage]])
 end
 export def spritePos(x, y, sprtptr)#0
-    sprtptr=>s_ypos = y
-    sprtptr=>s_xpos = x
+    sprtptr=>s_ypos = y - sprtptr->s_ycenter
+    sprtptr=>s_xpos = x - sprtptr->s_xcenter
 end
 export def spritePosIndex(x, y, i)#0
     i = i & 15
     if drawList[i]
-        drawList[i]=>s_ypos = y
-        drawList[i]=>s_xpos = x
+        drawList[i]=>s_ypos = y - drawList[i]->s_ycenter
+        drawList[i]=>s_xpos = x - drawList[i]->s_xcenter
     fin
 end
 export def spriteDrawList#0
diff --git a/src/samplesrc/hgrtest.pla b/src/samplesrc/hgrtest.pla
index 1083c25..9646a73 100644
--- a/src/samplesrc/hgrtest.pla
+++ b/src/samplesrc/hgrtest.pla
@@ -51,11 +51,11 @@ def testblt(sprtnum)#0
   while ^$C000 < 128
     for k = 0 to sprtnum
       i[k] = i[k] + ii[k]
-      if i[k] < -10 or i[k] > 280
+      if i[k] < 0 or i[k] > 279
         ii[k] = -ii[k]
       fin
       j[k] = j[k] + jj[k]
-      if j[k] < -10 or j[k] > 192
+      if j[k] < 0 or j[k] > 191
         jj[k] = -jj[k]
       fin
       spritePosIndex(i[k], j[k], k)
@@ -67,7 +67,7 @@ end
 
 hgrMode
 spriteDrawBuf(hgrDrawBuf(0)) // So we can see the compile process
-sprtBall = spriteCompile(10, 10, @ball)
+sprtBall = spriteCompile(10, 10, 5, 5, @ball)
 hgrColor(0)
 hgrClear()
 testline