cool-bun-demo/main.c

#include <stdio.h>

#include <clib/exec_protos.h>
#include <clib/graphics_protos.h>
#include <exec/exec.h>

#include <hardware/custom.h>
#include <hardware/dmabits.h>
#include <hardware/cia.h>

#include <graphics/gfx.h>

#include "system/blitter.h"
#include "system/copper.h"
#include "system/system.h"
#include "system/sprite.h"

#include "screen.h"
#include "types.h"
#include "bun.h"

extern struct Custom far custom;
extern struct CIA far ciaa;

// change to 0 to not render sprites
#define RENDER_SPRITES (1)

struct ScreenDefinition screenDefinition;
struct ActiveScreenBufferDetails activeScreenBufferDetails;

/**
 * The locations within the copperlist data where the bitplanes are referenced.
 * We change these areas of memory directly to implement double buffering.
 * Addresses are to the high, then low, word of the plane memory address in the copperlist.
 *
 * @see addDisplayToCopperlist
 */
void *copperlistBitplanePointers[8][2];

uint16_t custom_color = (uint16_t)offsetof(Custom, color);
uint16_t custom_sprite = (uint16_t)offsetof(Custom, sprpt);
uint16_t custom_sprite_control = (uint16_t)offsetof(Custom, spr);

extern uint8_t chip TopazBitplanes[];
extern uint16_t chip CopperColors[];
extern uint16_t chip SpriteCopperlist[];
extern uint16_t chip SpriteData[];
extern uint8_t chip MaskBitplane[];

#define TOPAZ_WIDTH_PIXELS (160)
#define TOPAZ_WIDTH_BYTES (TOPAZ_WIDTH_PIXELS / 8)
#define TOPAZ_WIDTH_WORDS (TOPAZ_WIDTH_PIXELS / 16)

#define BLTSIZE(w, h) (w + (h << 6))

void renderTopaz(void) {
  int plane;

  uint16_t bltcon0, bltcmod;
  uint8_t *bltbpt;

  bltcon0 = 0xca + (1 << 8) + (1 << 9) + (1 << 10) + (1 << 11);
  bltcmod = screenDefinition.byteWidth - TOPAZ_WIDTH_BYTES;
  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 = activeScreenBufferDetails.planes[plane] + 8;
    custom.bltdpt = activeScreenBufferDetails.planes[plane] + 8;
    custom.bltamod = 0;
    custom.bltbmod = 0;
    custom.bltcmod = bltcmod;
    custom.bltdmod = bltcmod;
    custom.bltsize = BLTSIZE(TOPAZ_WIDTH_WORDS, 256);

    bltbpt += TOPAZ_WIDTH_BYTES * 256;

    WaitBlit();
  }
}

#define COPPERLIST_SIZE (10000)

uint16_t *copperlist;

void buildCopperlist(void) {
  uint32_t spriteDataPointer;
  uint16_t *currentCopperlist,
    *currentCopperColors,
    *currentSpriteCopperlist;
  int i, j, y;
  uint16_t spriteSetupRegisters[3];

  copperlist = prepareNewCopperlist(COPPERLIST_SIZE);

  currentCopperlist = addDisplayToCopperlist(
    copperlist,
    &screenDefinition,
    &activeScreenBufferDetails,
    &copperlistBitplanePointers
  );

  currentCopperColors = CopperColors;
  currentSpriteCopperlist = SpriteCopperlist;

  COPPERLIST_MOVE(currentCopperlist, custom_color, 0x3a6);
  COPPERLIST_MOVE(currentCopperlist, custom_color + 2, 0x000);
  COPPERLIST_MOVE(currentCopperlist, custom_color + 4, 0xfff);

  if (RENDER_SPRITES) {
    for (i = 0; i < 8; ++i) {
      spriteDataPointer = (uint32_t)&SpriteData;
      spriteDataPointer += ((256 + 2) * 4) * i;

      COPPERLIST_MOVE_POINTER(
        currentCopperlist,
        custom_sprite + i * 4,
        spriteDataPointer
      );
    }
  } else {
    printf("Skipping render\n");
    currentCopperlist = setUpEmptySpritesInCopperlist(currentCopperlist);
  }

  for (y = 0; y < 256; ++y) {
    if (RENDER_SPRITES) {
      for (i = 0; i < 8; ++i) {
        spriteSetupRegisters[0] = custom_color + 32 + (
          // sprite color group
          (i / 2) * 4 +
          // 0 is transparent
          1 +
          i % 2
        ) * 2;
        spriteSetupRegisters[1] = custom_sprite_control + i * 8;
        spriteSetupRegisters[2] = custom_sprite_control + i * 8 + 2;

        for (j = 0; j < 3; ++j) {
          COPPERLIST_MOVE(
            currentCopperlist,
            spriteSetupRegisters[j],
            *(currentSpriteCopperlist++)
          );
        }
      }
    } else {
      printf("Skipping render\n");
    }

    for (i = 3; i < 8; ++i) {
      COPPERLIST_MOVE(
        currentCopperlist,
        custom_color + (i * 2),
        *(currentCopperColors++)
      );
    }

    COPPERLIST_WAIT(
      currentCopperlist,
      (31 + (256 / 4)),
      (44 + y),
      0xFFFE
    );
  }

  endCopperlist(currentCopperlist);
}

int main(void) {
  int i;

  struct BunRenderer bunRenderer;

  printf("\nCool bun blitter, copper, and sprite demo by John Bintz\n");
  printf("\n");
  printf("This is my first real go at writing graphics code for the Amiga.\n");
  printf("It's a combination of C (SAS/C) and Assembler (DevPac), with a Ruby\n");
  printf("script to do some image processing. The screen only uses three\n");
  printf("bitplanes -- one color is the background, two colors are the flying\n");
  printf("cool bun logo white and black, and the remaining 5 colors are used\n");
  printf("by the Topaz smiling art. The Ruby script will process the PNG file\n");
  printf("and figure out the best 5 colors (plus b&w) for that line of the\n");
  printf("image, setting the colors via copperlist for that line.\n");
  printf("It also builds the clipping mask for the blitter.\n\n");

  printf("And, I'm also using sprites to add more colors to the Topaz art.\n");
  printf("The Ruby script will figure out what small areas of each line weren't\n");
  printf("covered by the bitplane colors and use the 8 available sprites,\n");
  printf("changing the colors on each line via copper, to fill in the gaps.\n");
  printf("Cool buns are animated via blitter rather than sprites, but I\n");
  printf("managed to get it to run at a decent speed regardless.\n");

  printf("\nEnjoy, and thanks for watching!\n");
  printf("John (theindustriousrabbit.com)\n\n");

  allocateDoubleBufferedScreenMemory(
    &screenDefinition,
    &activeScreenBufferDetails,
    SCREEN_WIDTH,
    SCREEN_HEIGHT,
    3
  );

  setupBunRenderer(
    &bunRenderer,
    &screenDefinition,
    &activeScreenBufferDetails
  );

  buildCopperlist();


  /*
  copperlist debugging
  for (i = 0; i < 20; ++i) {
    printf(
      "%x %x %x %x\n",
      *(copperlist + (i * 4)),
      *(copperlist + (i * 4) + 1),
      *(copperlist + (i * 4) + 2),
      *(copperlist + (i * 4) + 3)
    );
  }
  */

  takeOverSystem();

  setCopperlist(copperlist);
  setUpDisplay((uint32_t)screenDefinition.bitplanes);

  i = 0;

  while (1) {
    swapCurrentScreenBuffer(&screenDefinition, &activeScreenBufferDetails);

    clearCurrentBuns(&bunRenderer);

    renderBunFrame(i, &bunRenderer);

    renderTopaz();

    updateDisplayInCopperList(
      &screenDefinition,
      &activeScreenBufferDetails,
      copperlistBitplanePointers
    );

    WaitBOF(250);

    if ((ciaa.ciapra >> 6) != 3) break;

    i++;
    i %= FRAMES_FOR_SCREEN;
  }

  giveBackSystem();

  teardownScreen(&screenDefinition);

  freeCopperlist(copperlist);

  teardownBunRenderer();

  return 0;
}