(wip)

bun.c

@@ -0,0 +1,166 @@
+#include "screen.h"
+#include "bun.h"
+
+extern unsigned char far coolbun[];
+
+unsigned char *coolbunArea;
+
+#define COOL_BUN_WIDTH (32)
+#define COOL_BUN_WIDTH_BYTES (COOL_BUN_WIDTH / 8)
+#define COOL_BUN_HEIGHT (32)
+#define COOL_BUN_PLANES (2)
+
+#define COOL_BUN_PLANE_SIZE (COOL_BUN_WIDTH_BYTES * COOL_BUN_HEIGHT)
+#define COOL_BUN_MEMORY_SIZE (COOL_BUN_PLANE_SIZE * COOL_BUN_PLANES)
+
+void setupBun() {
+  unsigned char *currentCoolBunArea, *currentCoolBun;
+
+  coolbunArea = AllocMem(COOL_BUN_MEMORY_SIZE, MEMF_CHIP | MEMF_CLEAR);
+  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) {
+        *(currentCoolBunArea++) = *(currentCoolBun++);
+      }
+    }
+  }
+}
+
+void teardownBun() {
+  FreeMem(coolbunArea, COOL_BUN_MEMORY_SIZE);
+}
+
+void bun_offRightSide(int plusXValue, int y, struct ScreenSetup *screenSetup) {
+  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.bltcon1 = (shift << 12);
+
+    custom.bltadat = 0xffff;
+    custom.bltbpt = coolbunArea + plane * COOL_BUN_PLANE_SIZE;
+    custom.bltdpt = screenSetup->memoryStart +
+      plane * screenSetup->nextBitplaneAdvance +
+      (y * screenSetup.width + screenSetup.width - COOL_BUN_WIDTH) / 8
+      + wordShift * 2;
+
+    custom.bltafwm = 0xffff;
+    bltalwm = 0x0000;
+    for (i = 0; i < 15 - shift; ++i) {
+      bltalwm += (1 << (15 - i));
+    }
+    custom.bltalwm = bltalwm;
+
+    custom.bltbmod = wordShift * 2;
+    custom.bltdmod = (screenSetup.width - COOL_BUN_WIDTH) / 8 + wordShift * 2;
+
+    custom.bltsize = 2 - wordShift + (COOL_BUN_HEIGHT << 6);
+
+    WaitBlit();
+  }
+}
+
+#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;
+  uint8_t wordShift = (minusXValue >> 4);
+  uint8_t i;
+  uint16_t bltalwm;
+
+  // y can't be 0 otherwise we will corrupt memory for now
+  if (y == 0) return;
+
+  for (plane = 0; plane < 2; ++plane) {
+    // shift left, so descending
+    custom.bltcon0 = BLTCON0(0xc0, 0, 1, 0, 1, shift);
+    custom.bltcon1 = BLTCON1(1, shift);
+
+    // 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;
+
+    // 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.bltafwm = 0xffff;
+    bltalwm = 0x0000;
+    for (i = 0; i < 15 - shift; ++i) {
+      bltalwm += (1 << i);
+    }
+    custom.bltalwm = bltalwm;
+
+    custom.bltbmod = wordShift * 2;
+    custom.bltdmod = screenSetup.width / 8 - 4 + wordShift * 2;
+
+    custom.bltsize = 2 - wordShift + (COOL_BUN_HEIGHT << 6);
+
+    WaitBlit();
+  }
+}
+
+void bun_anywhere(int x, int y, struct ScreenSetup *screenSetup) {
+  uint8_t plane;
+  uint8_t shift = x & 15;
+  uint8_t needsExtraWord = shift != 0;
+
+  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
+    custom.bltcon0 = 0xc0 + (1 << 8) + (1 << 10) + (shift << 12);
+    custom.bltcon1 = (shift << 12);
+
+    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 = screenSetup.memoryStart;
+    custom.bltafwm = 0xffff;
+    if (needsExtraWord) {
+      custom.bltalwm = 0x0000;
+    } else {
+      custom.bltalwm = 0xffff;
+    }
+    custom.bltbmod = -(needsExtraWord * 2);
+    custom.bltdmod = (screenSetup.width / 8) - COOL_BUN_WIDTH_BYTES - (needsExtraWord * 2);
+    custom.bltsize = (2 + needsExtraWord) + (COOL_BUN_HEIGHT << 6);
+
+    WaitBlit();
+  }
+}
+
+void renderBun(int x, int y, struct CurrentScreen *currentScreen) {
+  /**
+    * Conditions that will cause the program to crash if met. If your bun
+    * isn't rendering, it's due to here.
+    *
+    * TODO: Handle top/bottom off-screen as well.
+    */
+  if (x < -31) return;
+  if (x > currentScreen->pixelWidth + 31) return;
+  if (y < 1) return;
+  if (y > currentScreen->pixelHeight- COOL_BUN_HEIGHT - 1) return;
+
+  if (x < 0) {
+    bun_offLeftSide(-x, y, currentScreen);
+  } else if (x > screenSetup.width - COOL_BUN_WIDTH) {
+    bun_offRightSide(x - (currentScreen->pixelWidth - COOL_BUN_WIDTH), y, currentScreen);
+  } else {
+    bun_anywhere(x, y, currentScreen);
+  }
+}
+

bun.h

@@ -0,0 +1,10 @@
+#ifndef __BUN_H__
+#define __BUN_H__
+
+#include "screen.h"
+
+void setupBun();
+void renderBun(int x, int y, struct ScreenSetup *screenSetup);
+void teardownBun();
+
+#endif

main.c

@@ -15,17 +15,9 @@
 
 #include "screen.h"
 #include "types.h"
+#include "bun.h"
 
 extern struct Custom far custom;
-extern unsigned char far coolbun[];
-
-#define COOL_BUN_WIDTH (32)
-#define COOL_BUN_WIDTH_BYTES (COOL_BUN_WIDTH / 8)
-#define COOL_BUN_HEIGHT (32)
-#define COOL_BUN_PLANES (2)
-
-#define COOL_BUN_PLANE_SIZE (COOL_BUN_WIDTH_BYTES * COOL_BUN_HEIGHT)
-#define COOL_BUN_MEMORY_SIZE (COOL_BUN_PLANE_SIZE * COOL_BUN_PLANES)
 
 // this should be large enough to hold one bitplane of the largest object
 // you are blitting, plus one additional word on each side
@@ -35,160 +27,30 @@ extern unsigned char far coolbun[];
 
 volatile short *dbg = (volatile short *)0x100;
 
-unsigned char *coolbunArea;
 unsigned char *scratchArea;
 struct ScreenSetup screenSetup;
+struct CurrentScreen currentScreen;
 
-void bun_offRightSide(int plusXValue, int y) {
+#define offsetof(s, m) &((struct s *)0)->m
-  uint8_t i, plane = 0;
+uint16_t custom_color = (uint16_t)offsetof(Custom, color);
-  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.bltcon1 = (shift << 12);
-
-    custom.bltadat = 0xffff;
-    custom.bltbpt = coolbunArea + plane * COOL_BUN_PLANE_SIZE;
-    custom.bltdpt = screenSetup.memoryStart + plane * screenSetup.nextBitplaneAdvance + (y * screenSetup.width + screenSetup.width - COOL_BUN_WIDTH) / 8 + wordShift * 2;
-
-    custom.bltafwm = 0xffff;
-    bltalwm = 0x0000;
-    for (i = 0; i < 15 - shift; ++i) {
-      bltalwm += (1 << (15 - i));
-    }
-    custom.bltalwm = bltalwm;
-
-    custom.bltbmod = wordShift * 2;
-    custom.bltdmod = (screenSetup.width - COOL_BUN_WIDTH) / 8 + wordShift * 2;
-
-    custom.bltsize = 2 - wordShift + (COOL_BUN_HEIGHT << 6);
-
-    WaitBlit();
-  }
-}
-
-void bun_offLeftSide(int minusXValue, int y) {
-  unsigned char plane;
-  uint8_t shift = minusXValue & 15;
-  uint8_t wordShift = (minusXValue >> 4);
-  uint8_t i;
-  uint16_t bltalwm;
-
-  // y can't be 0 otherwise we will corrupt memory for now
-  if (y == 0) return;
-
-  for (plane = 0; plane < 2; ++plane) {
-    // shift left, so desccending
-    custom.bltcon0 = 0xc0 + (1 << 8) + (1 << 10) + (shift << 12);
-    custom.bltcon1 = (1 << 1) + (shift << 12);
-
-    // 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;
-
-    // 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.bltafwm = 0xffff;
-    bltalwm = 0x0000;
-    for (i = 0; i < 15 - shift; ++i) {
-      bltalwm += (1 << i);
-    }
-    custom.bltalwm = bltalwm;
-
-    custom.bltbmod = wordShift * 2;
-    custom.bltdmod = screenSetup.width / 8 - 4 + wordShift * 2;
-
-    custom.bltsize = 2 - wordShift + (COOL_BUN_HEIGHT << 6);
-
-    WaitBlit();
-  }
-}
-
-void bun_anywhere(int x, int y) {
-  uint8_t plane;
-  uint8_t shift = x & 15;
-  uint8_t needsExtraWord = shift != 0;
-
-  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
-    custom.bltcon0 = 0xc0 + (1 << 8) + (1 << 10) + (shift << 12);
-    custom.bltcon1 = (shift << 12);
-
-    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 = screenSetup.memoryStart;
-    custom.bltafwm = 0xffff;
-    if (needsExtraWord) {
-      custom.bltalwm = 0x0000;
-    } else {
-      custom.bltalwm = 0xffff;
-    }
-    custom.bltbmod = -(needsExtraWord * 2);
-    custom.bltdmod = (screenSetup.width / 8) - COOL_BUN_WIDTH_BYTES - (needsExtraWord * 2);
-    custom.bltsize = (2 + needsExtraWord) + (COOL_BUN_HEIGHT << 6);
-
-    WaitBlit();
-  }
-}
-
-void renderBun(int x, int y) {
-  if (x < -31) return;
-  if (x > screenSetup.width + 31) return;
-  if (y < 1) return;
-  if (y > screenSetup.height - COOL_BUN_HEIGHT - 1) return;
-
-  if (x < 0) {
-    bun_offLeftSide(-x, y);
-  } else if (x > screenSetup.width - COOL_BUN_WIDTH) {
-    bun_offRightSide(x - (screenSetup.width - COOL_BUN_WIDTH), y);
-  } else {
-    bun_anywhere(x, y);
-  }
-}
 
 int main(void) {
   uint16_t *copperlist, *currentCopperlist;
   int i, x, y, plane, result;
   int blitShiftRight, memoryXOffset, blitWidth;
 
-  int bunPosition = -31;
+  color_t colors[8];
-
-  color_t colors[16];
-
-  unsigned char *currentCoolBunArea, *currentCoolBun;
-
-  coolbunArea = AllocMem(COOL_BUN_MEMORY_SIZE, MEMF_CHIP | MEMF_CLEAR);
-  currentCoolBun = coolbun;
-
-  scratchArea = AllocMem(SCRATCH_AREA_MEMORY_SIZE, MEMF_CHIP | MEMF_CLEAR);
 
   colors[0] = 0x09b8;
   colors[1] = 0x0000;
   colors[2] = 0x0fff;
   colors[3] = 0x000f;
 
-  prepareScreen(&screenSetup, SCREEN_WIDTH, SCREEN_HEIGHT, 4);
+  setupScreen(&screenSetup, SCREEN_WIDTH, SCREEN_HEIGHT, 3);
-  allocateScreenMemory(&screenSetup);
+  setupInitialCurrentScreen(&screenSetup, &currentScreen);
-
-  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) {
-        *(currentCoolBunArea++) = *(currentCoolBun++);
-      }
-    }
-  }
 
+  teardownScreen(&screenSetup);
+  return 0;
 
   // blitter copy the first bitplane row down to the second
 
@@ -200,11 +62,38 @@ int main(void) {
   setUpDisplay(&screenSetup);
 
   currentCopperlist = addDisplayToCopperlist(copperlist, &screenSetup);
-  currentCopperlist = addColorsToCopperlist(currentCopperlist, colors, 16);
+  //currentCopperlist = addColorsToCopperlist(currentCopperlist, colors, 16);
+  *(currentCopperlist++) = custom_color;
+  *(currentCopperlist++) = 0x000;
+
+  *(currentCopperlist++) = custom_color + 2;
+  *(currentCopperlist++) = 0x000;
+
+  *(currentCopperlist++) = custom_color + 4;
+  *(currentCopperlist++) = 0xfff;
+
+  *(currentCopperlist++) = custom_color + 6;
+  *(currentCopperlist++) = 0x00F;
+
+  for (y = 0; y < 256; ++y) {
+    *(currentCopperlist++) = 1 + (31 << 1) + ((44 + y) << 8);
+    *(currentCopperlist++) = 0xFFFE;
+    *(currentCopperlist++) = custom_color;
+    *(currentCopperlist++) = 0x9b8;
+
+    *(currentCopperlist++) = 1 + (31 + (320 / 4) << 1) + ((44 + y) << 8);
+    *(currentCopperlist++) = 0xFFFE;
+    *(currentCopperlist++) = custom_color;
+    *(currentCopperlist++) = 0x000;
+  }
+
   endCopperlist(currentCopperlist);
 
   for (i = -31; i < screenSetup.width - 1; ++i) {
-    y = WaitBOF(250);
+    //y = WaitBOF(250);
+    WaitTOF();
+
+    /*
     for (plane = 0; plane < 2; ++plane) {
       custom.bltcon0 = 0xc0 + (1 << 8);
       custom.bltcon1 = 0;
@@ -216,18 +105,22 @@ int main(void) {
       custom.bltsize = 20 + (COOL_BUN_MEMORY_SIZE << 6);
       WaitBlit();
     }
+    */
 
-    renderBun(i, 45);
+    renderBun(i, 45, &screenSetup);
+  }
+
+  for (i = 0; i < 100; ++i) {
+    WaitTOF();
   }
 
   giveBackSystem();
 
-  freeScreenMemory(&screenSetup);
+  freeScreen(&screenSetup);
 
   freeCopperlist(copperlist);
 
-  FreeMem(coolbunArea, COOL_BUN_MEMORY_SIZE);
+  teardownBun();
-  FreeMem(scratchArea, SCRATCH_AREA_MEMORY_SIZE);
 
   return 0;
 }

screen.c

@@ -4,31 +4,69 @@
 #include <clib/exec_protos.h>
 #include <exec/memory.h>
 
-void allocateScreenMemory(struct ScreenSetup *screenSetup) {
+/**
-  char *memory = (char *)AllocMem(
+ * Includes double buffer space
+ */
+#define TOTAL_SCREEN_SETUP_SIZE(s) ((s->width / 8) * s->height * s->bitplanes * 2)
+
+void setupScreen(
+  struct ScreenSetup *screenSetup,
+  uint16_t width,
+  uint16_t height,
+  uint8_t bitplanes
+) {
+  unsigned char *memory;
+
+  screenSetup->width = width;
+  screenSetup->height = height;
+  screenSetup->bitplanes = bitplanes;
+
+  memory = (unsigned char *)AllocMem(
     TOTAL_SCREEN_SETUP_SIZE(screenSetup),
     MEMF_CLEAR | MEMF_CHIP
   );
 
   screenSetup->memoryStart = memory;
+  screenSetup->byteWidth = width / 8;
+
+  // memory is not interleaved
+  screenSetup->nextBitplaneAdvance = screenSetup->byteWidth * height;
+  screenSetup->nextBufferAdvance = screenSetup->nextBitplaneAdvance * bitplanes;
 }
 
-void freeScreenMemory(struct ScreenSetup *screenSetup) {
+void teardownScreen(
+  struct ScreenSetup *screenSetup
+) {
   FreeMem(
     screenSetup->memoryStart,
     TOTAL_SCREEN_SETUP_SIZE(screenSetup)
   );
 }
 
-void prepareScreen(
+void setCurrentScreen(
   struct ScreenSetup *screenSetup,
-  uint16_t width,
+  struct CurrentScreen *currentScreen,
-  uint16_t height,
+  short int buffer
-  uint8_t bitplanes
 ) {
-  screenSetup->width = width;
+  int plane;
-  screenSetup->height = height;
+
-  screenSetup->bitplanes = bitplanes;
+  currentScreen->currentBuffer = buffer;
-  screenSetup->nextBitplaneAdvance = width * height / 8;
+
-  screenSetup->currentBuffer = 0;
+  for (plane = 0; plane < screenSetup->bitplanes; ++plane) {
+    currentScreen->planes[plane] = screenSetup->memoryStart +
+      buffer * screenSetup->nextBufferAdvance +
+      plane * screenSetup->nextBitplaneAdvance;
   }
+}
+
+void setupInitialCurrentScreen(
+  struct ScreenSetup *screenSetup,
+  struct CurrentScreen *currentScreen
+) {
+  currentScreen->pixelWidth = screenSetup->width;
+  currentScreen->pixelHeight = screenSetup->height;
+  currentScreen->byteWidth = screenSetup->byteWidth;
+
+  setCurrentScreen(screenSetup, currentScreen, 0);
+}
+

screen.h

@@ -3,28 +3,41 @@
 
 #include "types.h"
 
-struct ScreenSetup {
-  short int width;
-  short int height;
-  short int bitplanes;
-  unsigned char *memoryStart;
-  short int nextBitplaneAdvance;
-
-  short int currentBuffer;
-};
-
 #define SCREEN_WIDTH (320)
 #define SCREEN_HEIGHT (256)
 
-#define TOTAL_SCREEN_SETUP_SIZE(s) ((s->width / 8) * s->height * s->bitplanes * 2)
+struct ScreenSetup {
+  // human entered
+  uint16_t width;
+  uint16_t height;
+  short int bitplanes;
 
-void allocateScreenMemory(struct ScreenSetup *screenSetup);
+  // calculated
-void freeScreenMemory(struct ScreenSetup *screenSetup);
+  unsigned char *memoryStart;
-void prepareScreen(
+  uint16_t byteWidth;
+  uint16_t nextBitplaneAdvance;
+  uint16_t nextBufferAdvance;
+};
+
+struct CurrentScreen {
+  uint16_t currentBuffer;
+  uint16_t pixelWidth;
+  uint16_t byteWidth;
+  uint16_t pixelHeight;
+  unsigned char *planes[8];
+};
+
+void setupScreen(
   struct ScreenSetup *screenSetup,
   uint16_t width,
   uint16_t height,
   uint8_t bitplanes
 );
+void teardownScreen(struct ScreenSetup *screenSetup);
 
+void setCurrentScreen(
+  struct ScreenSetup *screenSetup,
+  struct CurrentScreen *currentScreen,
+  short int buffer
+);
 #endif

smakefile

@@ -1,3 +1,5 @@
+MAIN_OBJS = main.o images.o system.lib screen.o bun.o
+
 all: main
 
 .c.o:
@@ -9,8 +11,8 @@ all: main
 system.lib: system/system.o system/copper.o system/blitter.o
 	sc objectlibrary=system.lib system/system.o system/copper.o system/blitter.o
 
-main: main.o images.o system.lib screen.o
+main: $(MAIN_OBJS)
-	sc link to main main.o system.lib screen.o images.o
+	sc link to main $(MAIN_OBJS)
 
 test: blitter_test.o blitter.o system.o
 	sc link to blitter_test identifierlength=32 math=standard blitter_test.o blitter.o cutest/CuTest.c system.o