this is as optimized as the code will reasonably get

we just need to blit less stuff

bun.c

@@ -92,7 +92,7 @@ void bun_offRightSide(
   uint8_t i, plane = 0;
   uint8_t shift = plusXValue & 15;
   uint8_t wordShift = (plusXValue >> 4);
-  uint16_t bltalwm;
+  uint16_t bltalwm, bltcon0, bltcon1, bltdmod, bltsize;
 
   bunClear->memoryStartOffsetBytes =  (y * screenSetup->byteWidth) +
     screenSetup->byteWidth - COOL_BUN_WIDTH_BYTES +
@@ -106,9 +106,17 @@ void bun_offRightSide(
     bltalwm += (1 << (15 - i));
   }
 
+  bltcon0 = BLTCON0(0xc0, 0, 1, 0, 1, shift);
+  bltcon1 = BLTCON1(bunClear->direction, shift);
+
+  bltdmod = screenSetup->byteWidth - COOL_BUN_WIDTH_BYTES +
+    wordShift * 2;
+
+  bltsize = bunClear->widthWords + (bunClear->heightRows << 6);
+
   for (plane = 0; plane < 2; ++plane) {
-    custom.bltcon0 = BLTCON0(0xc0, 0, 1, 0, 1, shift);
+    custom.bltcon0 = bltcon0;
-    custom.bltcon1 = BLTCON1(bunClear->direction, shift);
+    custom.bltcon1 = bltcon1;
 
     custom.bltadat = 0xffff;
     custom.bltbpt = coolbunPlaneStarts[BUN_OFF_LEFT_SIDE][plane];
@@ -119,10 +127,9 @@ void bun_offRightSide(
     custom.bltalwm = bltalwm;
 
     custom.bltbmod = wordShift * 2;
-    custom.bltdmod = screenSetup->byteWidth - COOL_BUN_WIDTH_BYTES +
+    custom.bltdmod = bltdmod;
-      wordShift * 2;
 
-    custom.bltsize = bunClear->widthWords + (bunClear->heightRows << 6);
+    custom.bltsize = bltsize;
 
     WaitBlit();
   }
@@ -139,7 +146,7 @@ void bun_offLeftSide(
   uint8_t shift = minusXValue & 15;
   uint8_t wordShift = (minusXValue >> 4);
   uint8_t i;
-  uint16_t bltalwm;
+  uint16_t bltalwm, bltcon0, bltcon1, bltdmod, bltsize;
 
   // y can't be 0 otherwise we will corrupt memory for now
   if (y == 0) return;
@@ -155,10 +162,16 @@ void bun_offLeftSide(
     bltalwm += (1 << i);
   }
 
+  bltcon0 = BLTCON0(0xc0, 0, 1, 0, 1, shift);
+  bltcon1 = BLTCON1(bunClear->direction, shift);
+  bltdmod = screenSetup->byteWidth - 4 + wordShift * 2;
+
+  bltsize = bunClear->widthWords + (bunClear->heightRows << 6);
+
   for (plane = 0; plane < 2; ++plane) {
     // shift left, so descending
-    custom.bltcon0 = BLTCON0(0xc0, 0, 1, 0, 1, shift);
+    custom.bltcon0 = bltcon0;
-    custom.bltcon1 = BLTCON1(bunClear->direction, shift);
+    custom.bltcon1 = bltcon1;
 
     // a has a mask we're shifting
     custom.bltadat = 0xffff;
@@ -172,9 +185,9 @@ void bun_offLeftSide(
     custom.bltalwm = bltalwm;
 
     custom.bltbmod = wordShift * 2;
-    custom.bltdmod = screenSetup->byteWidth - 4 + wordShift * 2;
+    custom.bltdmod = bltdmod;
 
-    custom.bltsize = bunClear->widthWords + (bunClear->heightRows << 6);
+    custom.bltsize = bltsize;
 
     WaitBlit();
   }
@@ -190,6 +203,7 @@ void bun_anywhere(
   uint8_t plane;
   uint8_t shift = x & 15;
   uint8_t needsExtraWord = shift != 0;
+  uint16_t bltcon0, bltcon1, bltalwm, bltbmod, bltdmod, bltsize;
 
   bunClear->memoryStartOffsetBytes = WORD_ALIGNED_BYTE_POSITION(screenSetup->width, x, y);
 
@@ -197,13 +211,23 @@ void bun_anywhere(
   bunClear->widthWords = 2 + needsExtraWord;
   bunClear->direction = BLITTER_ASCENDING;
 
-  for (plane = 0; plane < 2; ++plane) {
-    // if we extend the bun area by a word, we only need one write
-
   // buns will never interfere with a background so they don't need a mask
-    // they do need the scratch area though
+  bltcon0 = BLTCON0(0xc0, 0, 1, 0, 1, shift);
-    custom.bltcon0 = BLTCON0(0xc0, 0, 1, 0, 1, shift);
+  bltcon1 = BLTCON1(bunClear->direction, shift);
-    custom.bltcon1 = BLTCON1(bunClear->direction, shift);
+
+  if (needsExtraWord) {
+    bltalwm = 0x0000;
+  } else {
+    bltalwm = 0xffff;
+  }
+
+  bltbmod = -(needsExtraWord * 2);
+  bltdmod = screenSetup->byteWidth - COOL_BUN_WIDTH_BYTES - (needsExtraWord * 2);
+  bltsize = bunClear->widthWords + (bunClear->heightRows << 6);
+
+  for (plane = 0; plane < 2; ++plane) {
+    custom.bltcon0 = bltcon0;
+    custom.bltcon1 = bltcon1;
 
     custom.bltadat = 0xffff;
     custom.bltbpt = coolbunPlaneStarts[BUN_ANYWHERE][plane];
@@ -212,15 +236,11 @@ void bun_anywhere(
 
    // custom.bltdpt = screenSetup.memoryStart;
     custom.bltafwm = 0xffff;
-    if (needsExtraWord) {
+    custom.bltalwm = bltalwm;
-      custom.bltalwm = 0x0000;
-    } else {
-      custom.bltalwm = 0xffff;
-    }
 
-    custom.bltbmod = -(needsExtraWord * 2);
+    custom.bltbmod = bltbmod;
-    custom.bltdmod = screenSetup->byteWidth - COOL_BUN_WIDTH_BYTES - (needsExtraWord * 2);
+    custom.bltdmod = bltdmod;
-    custom.bltsize = bunClear->widthWords + (bunClear->heightRows << 6);
+    custom.bltsize = bltsize;
 
     WaitBlit();
   }
@@ -370,22 +390,30 @@ void clearCurrentBuns(
 ) {
   int bun, plane;
   struct BunClear *currentBunClear;
+  uint16_t bltcon0, bltcon1, bltdmod, bltsize;
 
   if (!hasBunClear[bunRenderer->currentScreen->currentBuffer]) return;
 
+  bltcon0 = 0xc0 + (1 << 8);
+
   for (bun = 0; bun < BUN_COUNT; ++bun) {
     currentBunClear = &bunClearForScreen[bunRenderer->currentScreen->currentBuffer][bun];
 
+    bltcon1 = BLTCON1(currentBunClear->direction, 0);
+    bltdmod = bunRenderer->screenSetup->byteWidth - (currentBunClear->widthWords * 2);
+    bltsize = currentBunClear->widthWords + (currentBunClear->heightRows << 6);
+
     for (plane = 0; plane < 2; ++plane) {
-      custom.bltcon0 = 0xc0 + (1 << 8);
+      custom.bltcon0 = bltcon0;
-      custom.bltcon1 = BLTCON1(currentBunClear->direction, 0);
+      custom.bltcon1 = bltcon1;
       custom.bltadat = 0x0000;
       custom.bltafwm = 0xffff;
       custom.bltalwm = 0xffff;
       custom.bltdpt = bunRenderer->currentScreen->planes[plane] +
         currentBunClear->memoryStartOffsetBytes;
-      custom.bltdmod = bunRenderer->screenSetup->byteWidth - (currentBunClear->widthWords * 2);
+      custom.bltdmod = bltdmod;
-      custom.bltsize = currentBunClear->widthWords + (currentBunClear->heightRows << 6);
+      custom.bltsize = bltsize;
+
       WaitBlit();
     }
   }

main.c

@@ -64,6 +64,37 @@ extern uint16_t chip SpriteCopperlist[];
 extern uint16_t chip SpriteData[];
 extern uint16_t chip MaskBitplane[];
 
+void renderTopaz(void) {
+  int plane;
+
+  uint16_t bltcon0, bltcmod;
+  uint8_t *bltbpt;
+
+  bltcon0 = 0xca + (1 << 8) + (1 << 9) + (1 << 10) + (1 << 11);
+  bltcmod = screenSetup.byteWidth - 32;
+  bltbpt = TopazBitplanes;
+
+  for (plane = 0; plane < 3; ++plane) {
+    custom.bltcon0 = bltcon0;
+    custom.bltcon1 = 0;
+    custom.bltafwm = 0xffff;
+    custom.bltalwm = 0xffff;
+    custom.bltapt = MaskBitplane;
+    custom.bltbpt = bltbpt;
+    custom.bltcpt = currentScreen.planes[plane];
+    custom.bltdpt = currentScreen.planes[plane];
+    custom.bltamod = 0;
+    custom.bltbmod = 0;
+    custom.bltcmod = bltcmod;
+    custom.bltdmod = bltcmod;
+    custom.bltsize = 16 + (256 << 6);
+
+    bltbpt += 32 * 256;
+
+    WaitBlit();
+  }
+}
+
 int main(void) {
   uint16_t *copperlist, *currentCopperlist, *currentCopperColors, result, *currentSpriteCopperlist;
   uint32_t spriteDataPointer;
@@ -78,7 +109,6 @@ int main(void) {
   colors[2] = 0x0fff;
   colors[3] = 0x000f;
 
-  printf("%x\n", &SpriteData);
   printf("setting up, i haven't crashed...yet.\n");
 
   setupScreen(&screenSetup, SCREEN_WIDTH, SCREEN_HEIGHT, 3);
@@ -101,7 +131,7 @@ int main(void) {
     &currentScreen,
     &copperlistBitplanePointers
   );
-  currentCopperlist = setUpEmptySpritesInCopperlist(currentCopperlist);
+  //currentCopperlist = setUpEmptySpritesInCopperlist(currentCopperlist);
 
   currentCopperColors = CopperColors;
   currentSpriteCopperlist = SpriteCopperlist;
@@ -198,26 +228,11 @@ int main(void) {
 
     renderBunFrame(i, &bunRenderer);
 
+    renderTopaz();
+
     /*
   */
 
-    for (plane = 0; plane < 3; ++plane) {
-      custom.bltcon0 = 0xca + (1 << 8) + (1 << 9) + (1 << 10) + (1 << 11);
-      custom.bltcon1 = 0;
-      custom.bltafwm = 0xffff;
-      custom.bltalwm = 0xffff;
-      custom.bltapt = MaskBitplane;
-      custom.bltbpt = TopazBitplanes + (plane * 32 * 256);
-      custom.bltcpt = currentScreen.planes[plane];
-      custom.bltdpt = currentScreen.planes[plane];
-      custom.bltamod = 0;
-      custom.bltbmod = 0;
-      custom.bltcmod = screenSetup.byteWidth - 32;
-      custom.bltdmod = screenSetup.byteWidth - 32;
-      custom.bltsize = 16 + (256 << 6);
-
-      WaitBlit();
-    }
 
     /*
     *(SpriteData) = SPRPOS(250, 44);
@@ -230,7 +245,6 @@ int main(void) {
       copperlistBitplanePointers
     );
 
-
     WaitTOF();
     
     if ((ciaa.ciapra >> 6) != 3) break;
@@ -255,8 +269,6 @@ int main(void) {
   }
 */
 
-  printf("%x %x", SPRPOS(250, 44), SPRCTL(250, 44, 44 + 256));
-
   freeCopperlist(copperlist);
 
   teardownBunRenderer();