code restructured

bun.c

@@ -1,6 +1,18 @@
+// Custom
+#include <hardware/custom.h>
+
+// WaitBlit()
+#include <clib/graphics_protos.h>
+
+// AllocMem(), FreeMem()
+#include <clib/exec_protos.h>
+#include <exec/memory.h>
+
 #include "screen.h"
 #include "bun.h"
+#include "system/system.h"
 
+// linked as raw bytes in assembler
 extern unsigned char far coolbun[];
 
 unsigned char *coolbunArea;
@@ -9,18 +21,28 @@ unsigned char *coolbunArea;
 #define COOL_BUN_WIDTH_BYTES (COOL_BUN_WIDTH / 8)
 #define COOL_BUN_HEIGHT (32)
 #define COOL_BUN_PLANES (2)
+#define COOL_BUN_LAST_ROW (COOL_BUN_HEIGHT - 1)
+#define COOL_BUN_LAST_ROW_BYTES (COOL_BUN_LAST_ROW * COOL_BUN_WIDTH_BYTES)
 
 #define COOL_BUN_PLANE_SIZE (COOL_BUN_WIDTH_BYTES * COOL_BUN_HEIGHT)
 #define COOL_BUN_MEMORY_SIZE (COOL_BUN_PLANE_SIZE * COOL_BUN_PLANES)
 
+#define BLTCON0( \
+  minterm, aChan, bChan, cChan, dChan, shift \
+) (minterm + (aChan << 11) + (bChan << 10) + (cChan << 9) + (dChan << 8) + (shift << 12))
+#define BLTCON1(descending, shift) ((descending << 1) + (shift << 12))
+
+extern struct Custom far custom;
+
 void setupBun() {
   unsigned char *currentCoolBunArea, *currentCoolBun;
+  unsigned int x, y, plane;
 
   coolbunArea = AllocMem(COOL_BUN_MEMORY_SIZE, MEMF_CHIP | MEMF_CLEAR);
+  currentCoolBunArea = coolbunArea;
   currentCoolBun = coolbun;
 
-  currentCoolBunArea = coolbunArea;
+  /*
-
   for (plane = 0; plane < COOL_BUN_PLANES; ++plane) {
     for (y = 0; y < COOL_BUN_HEIGHT; ++y) {
       for (x = 0; x < COOL_BUN_WIDTH_BYTES; ++x) {
@@ -28,28 +50,32 @@ void setupBun() {
       }
     }
   }
+  */
+
+  CopyMem(coolbun, coolbunArea, COOL_BUN_MEMORY_SIZE);
 }
 
 void teardownBun() {
   FreeMem(coolbunArea, COOL_BUN_MEMORY_SIZE);
 }
 
-void bun_offRightSide(int plusXValue, int y, struct ScreenSetup *screenSetup) {
+void bun_offRightSide(int plusXValue, int y, struct CurrentScreen *currentScreen) {
   uint8_t i, plane = 0;
   uint8_t shift = plusXValue & 15;
   uint8_t wordShift = (plusXValue >> 4);
   uint16_t bltalwm;
 
   for (plane = 0; plane < 2; ++plane) {
-    custom.bltcon0 = 0xc0 + (1 << 8) + (1 << 10) + (shift << 12);
+    custom.bltcon0 = BLTCON0(0xc0, 0, 1, 0, 1, shift);
-    custom.bltcon1 = (shift << 12);
+    custom.bltcon1 = BLTCON1(0, shift);
 
     custom.bltadat = 0xffff;
-    custom.bltbpt = coolbunArea + plane * COOL_BUN_PLANE_SIZE;
+    custom.bltbpt = coolbunArea +
-    custom.bltdpt = screenSetup->memoryStart +
+      plane * COOL_BUN_PLANE_SIZE;
-      plane * screenSetup->nextBitplaneAdvance +
+    custom.bltdpt = currentScreen->planes[plane] +
-      (y * screenSetup.width + screenSetup.width - COOL_BUN_WIDTH) / 8
+      (y * currentScreen->byteWidth) +
-      + wordShift * 2;
+      currentScreen->byteWidth - COOL_BUN_WIDTH_BYTES +
+      wordShift * 2;
 
     custom.bltafwm = 0xffff;
     bltalwm = 0x0000;
@@ -59,7 +85,8 @@ void bun_offRightSide(int plusXValue, int y, struct ScreenSetup *screenSetup) {
     custom.bltalwm = bltalwm;
 
     custom.bltbmod = wordShift * 2;
-    custom.bltdmod = (screenSetup.width - COOL_BUN_WIDTH) / 8 + wordShift * 2;
+    custom.bltdmod = currentScreen->byteWidth - COOL_BUN_WIDTH_BYTES +
+      wordShift * 2;
 
     custom.bltsize = 2 - wordShift + (COOL_BUN_HEIGHT << 6);
 
@@ -67,11 +94,6 @@ void bun_offRightSide(int plusXValue, int y, struct ScreenSetup *screenSetup) {
   }
 }
 
-#define BLTCON0( \
-  minterm, aChan, bChan, cChan, dChan, shift \
-) (minterm + (aChan << 11) + (bChan << 10) + (cChan << 9) + (dChan << 8) + (shift << 12)
-#define BLTCON1(descending, shift) ((descending << 1) + (shift << 12))
-
 void bun_offLeftSide(int minusXValue, int y, struct CurrentScreen *currentScreen) {
   unsigned char plane;
   uint8_t shift = minusXValue & 15;
@@ -90,10 +112,15 @@ void bun_offLeftSide(int minusXValue, int y, struct CurrentScreen *currentScreen
     // a has a mask we're shifting
     custom.bltadat = 0xffff;
     // b has bun data
-    custom.bltbpt = coolbunArea + 2 + ((COOL_BUN_HEIGHT - 1) * 4) + plane * COOL_BUN_PLANE_SIZE;
+    custom.bltbpt = coolbunArea + 2 +
+      COOL_BUN_LAST_ROW_BYTES +
+      plane * COOL_BUN_PLANE_SIZE;
 
     // d is the part on screen
-    custom.bltdpt = screenSetup.memoryStart + screenSetup.nextBitplaneAdvance * plane + (screenSetup.width * (y + COOL_BUN_HEIGHT - 1) / 8) + 2 - wordShift * 2;
+    custom.bltdpt = currentScreen->planes[plane] +
+      (currentScreen->byteWidth * (y + COOL_BUN_LAST_ROW)) +
+      2 -
+      wordShift * 2;
 
     custom.bltafwm = 0xffff;
     bltalwm = 0x0000;
@@ -103,7 +130,7 @@ void bun_offLeftSide(int minusXValue, int y, struct CurrentScreen *currentScreen
     custom.bltalwm = bltalwm;
 
     custom.bltbmod = wordShift * 2;
-    custom.bltdmod = screenSetup.width / 8 - 4 + wordShift * 2;
+    custom.bltdmod = currentScreen->byteWidth - 4 + wordShift * 2;
 
     custom.bltsize = 2 - wordShift + (COOL_BUN_HEIGHT << 6);
 
@@ -111,7 +138,7 @@ void bun_offLeftSide(int minusXValue, int y, struct CurrentScreen *currentScreen
   }
 }
 
-void bun_anywhere(int x, int y, struct ScreenSetup *screenSetup) {
+void bun_anywhere(int x, int y, struct CurrentScreen *currentScreen) {
   uint8_t plane;
   uint8_t shift = x & 15;
   uint8_t needsExtraWord = shift != 0;
@@ -121,12 +148,13 @@ void bun_anywhere(int x, int y, struct ScreenSetup *screenSetup) {
 
     // buns will never interfere with a background so they don't need a mask
     // they do need the scratch area though
-    custom.bltcon0 = 0xc0 + (1 << 8) + (1 << 10) + (shift << 12);
+    custom.bltcon0 = BLTCON0(0xc0, 0, 1, 0, 1, shift);
-    custom.bltcon1 = (shift << 12);
+    custom.bltcon1 = BLTCON1(0, shift);
 
     custom.bltadat = 0xffff;
     custom.bltbpt = coolbunArea + plane * COOL_BUN_PLANE_SIZE;
-    custom.bltdpt = screenSetup.memoryStart + WORD_ALIGNED_BYTE_POSITION(screenSetup.width, x, y) + screenSetup.nextBitplaneAdvance * plane;
+    custom.bltdpt = currentScreen->planes[plane] +
+      WORD_ALIGNED_BYTE_POSITION(currentScreen->pixelWidth, x, y);
 
    // custom.bltdpt = screenSetup.memoryStart;
     custom.bltafwm = 0xffff;
@@ -135,8 +163,9 @@ void bun_anywhere(int x, int y, struct ScreenSetup *screenSetup) {
     } else {
       custom.bltalwm = 0xffff;
     }
+
     custom.bltbmod = -(needsExtraWord * 2);
-    custom.bltdmod = (screenSetup.width / 8) - COOL_BUN_WIDTH_BYTES - (needsExtraWord * 2);
+    custom.bltdmod = currentScreen->byteWidth - COOL_BUN_WIDTH_BYTES - (needsExtraWord * 2);
     custom.bltsize = (2 + needsExtraWord) + (COOL_BUN_HEIGHT << 6);
 
     WaitBlit();
@@ -157,7 +186,7 @@ void renderBun(int x, int y, struct CurrentScreen *currentScreen) {
 
   if (x < 0) {
     bun_offLeftSide(-x, y, currentScreen);
-  } else if (x > screenSetup.width - COOL_BUN_WIDTH) {
+  } else if (x > currentScreen->pixelWidth - COOL_BUN_WIDTH) {
     bun_offRightSide(x - (currentScreen->pixelWidth - COOL_BUN_WIDTH), y, currentScreen);
   } else {
     bun_anywhere(x, y, currentScreen);

bun.h

@@ -4,7 +4,7 @@
 #include "screen.h"
 
 void setupBun();
-void renderBun(int x, int y, struct ScreenSetup *screenSetup);
+void renderBun(int x, int y, struct CurrentScreen *currentScreen);
 void teardownBun();
 
 #endif

main.c

@@ -46,12 +46,10 @@ int main(void) {
   colors[2] = 0x0fff;
   colors[3] = 0x000f;
 
+  setupBun();
   setupScreen(&screenSetup, SCREEN_WIDTH, SCREEN_HEIGHT, 3);
   setupInitialCurrentScreen(&screenSetup, &currentScreen);
 
-  teardownScreen(&screenSetup);
-  return 0;
-
   // blitter copy the first bitplane row down to the second
 
   copperlist = prepareNewCopperlist();
@@ -59,8 +57,10 @@ int main(void) {
   takeOverSystem();
 
   setCopperlist(copperlist);
-  setUpDisplay(&screenSetup);
+  setUpDisplay((uint32_t)screenSetup.bitplanes);
 
+  // TODO: [ ] A struct that can be filled with the locations in the copperlist where
+  //           bitplane addresses go
   currentCopperlist = addDisplayToCopperlist(copperlist, &screenSetup);
   //currentCopperlist = addColorsToCopperlist(currentCopperlist, colors, 16);
   *(currentCopperlist++) = custom_color;
@@ -107,7 +107,7 @@ int main(void) {
     }
     */
 
-    renderBun(i, 45, &screenSetup);
+    renderBun(i, 45, &currentScreen);
   }
 
   for (i = 0; i < 100; ++i) {
@@ -116,7 +116,7 @@ int main(void) {
 
   giveBackSystem();
 
-  freeScreen(&screenSetup);
+  teardownScreen(&screenSetup);
 
   freeCopperlist(copperlist);
 

system/blitter.h

@@ -4,9 +4,8 @@
 #include "types.h"
 #include "screen.h"
 
-#define WORD_ALIGNED_BYTE_POSITION(width, x, y) (((width * y + x) >> 3) & 0xfffe)
-#define WORD_ALIGNED_BYTE_X(x) (((x) >> 3) & 0xfffe)
 
+/*
 struct BlitAreaDetails {
   unsigned char *target;
   uint16_t drawAreaWidth;
@@ -77,5 +76,6 @@ void blit_marquee(
   uint16_t ey,
   uint16_t ty
 );
+*/
 
 #endif

system/system.h

@@ -4,6 +4,9 @@
 #include "types.h"
 #include "screen.h"
 
+#define WORD_ALIGNED_BYTE_POSITION(width, x, y) (((width * y + x) >> 3) & 0xfffe)
+#define WORD_ALIGNED_BYTE_X(x) (((x) >> 3) & 0xfffe)
+
 // this needs to be kept in sync with the XDEFs in system.s
 
 // copperlist
@@ -14,7 +17,7 @@ extern uint16_t* addColorsToCopperlist(uint16_t *copperlist, color_t[], int coun
 
 extern void takeOverSystem(void);
 extern void giveBackSystem(void);
-extern void setUpDisplay(struct ScreenSetup *);
+extern void setUpDisplay(uint32_t bitplaneCount);
 
 extern void myWaitBlit(void);
 extern uint16_t WaitBOF(uint16_t line);

system/system.s

@@ -205,16 +205,17 @@ _endCopperlist:
 
   RTS
 
-; @stack *ScreenSetup
+; @stack bitplaneCount
 _setUpDisplay:
-  MOVE.L 4(A7),A0
+  MOVE.L D2,-(SP)
+    MOVE.L 4(A7),D2
 
     LEA _custom,A1
 
     MOVEQ #0,D0
     MOVE.W #BPLCON0_COLOR,D0
     MOVEQ #0,D1
-  MOVE.W ScreenSetup_bitplanes(A0),D1
+    MOVE.W D2,D1
     AND.W #$7,D1
     ROL.W #8,D1
     ROL.W #4,D1
@@ -227,6 +228,7 @@ _setUpDisplay:
     MOVE.W #$2cc1,diwstop(A1)
     MOVE.W #$0038,ddfstrt(A1)
     MOVE.W #$00d0,ddfstop(A1)
+  MOVE.L (SP)+,D2
 
   RTS
 

types.h

@@ -4,6 +4,7 @@
 #include <exec/types.h>
 
 typedef unsigned short color_t;
+typedef unsigned long uint32_t;
 typedef unsigned short uint16_t;
 typedef unsigned char uint8_t;
 typedef signed char int8_t;