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

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

// this should be large enough to hold one bitplane of the largest object
// you are blitting, plus one additional word on each side
#define SCRATCH_AREA_WIDTH_BYTES (8)
#define SCRATCH_AREA_HEIGHT_ROWS (34)
#define SCRATCH_AREA_MEMORY_SIZE (SCRATCH_AREA_WIDTH_BYTES * SCRATCH_AREA_HEIGHT_ROWS)

volatile short *dbg = (volatile short *)0x100;

unsigned char *scratchArea;
struct ScreenSetup screenSetup;
struct CurrentScreen currentScreen;
void *copperlistBitplanePointers[8][2];
void *copperlistSpritePointers[8];

#define offsetof(s, m) &((struct s *)0)->m
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);

#define SPRPOS(x, y) (((y & 0xff) << 8) + ((x & 0x1fe) >> 1))
#define SPRCTL(x, y, height) ( \
  ((height & 0xff) << 8) + \
  ((y & 0x100) >> 6) + \
  ((height & 0x100) >> 7) + \
  (x & 1) \
)

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)

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 - 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 = currentScreen.planes[plane] + 8;
    custom.bltdpt = currentScreen.planes[plane] + 8;
    custom.bltamod = 0;
    custom.bltbmod = 0;
    custom.bltcmod = bltcmod;
    custom.bltdmod = bltcmod;
    custom.bltsize = TOPAZ_WIDTH_WORDS + (256 << 6);

    bltbpt += TOPAZ_WIDTH_BYTES * 256;

    WaitBlit();
  }
}

int main(void) {
  uint16_t *copperlist, *currentCopperlist, *currentCopperColors, result, *currentSpriteCopperlist;
  uint32_t spriteDataPointer;
  int i, x, y, height, plane;

  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");

  setupScreen(&screenSetup, SCREEN_WIDTH, SCREEN_HEIGHT, 3);
  setupInitialCurrentScreen(&screenSetup, &currentScreen);

  setupBunRenderer(&bunRenderer, &screenSetup, &currentScreen);

  // blitter copy the first bitplane row down to the second

  copperlist = prepareNewCopperlist();

  currentCopperlist = addDisplayToCopperlist(
    copperlist,
    &screenSetup,
    &currentScreen,
    &copperlistBitplanePointers
  );

  currentCopperColors = CopperColors;
  currentSpriteCopperlist = SpriteCopperlist;

  *(currentCopperlist++) = custom_color + 2;
  *(currentCopperlist++) = 0x000;

  *(currentCopperlist++) = custom_color + 4;
  *(currentCopperlist++) = 0xfff;

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

    *(currentCopperlist++) = custom_sprite + i * 4;
    *(currentCopperlist++) = (spriteDataPointer >> 16);

    *(currentCopperlist++) = custom_sprite + 2 + i * 4;
    *(currentCopperlist++) = (spriteDataPointer & 0xffff);
  }

  *(currentCopperlist++) = custom_color;
  *(currentCopperlist++) = 0x3a6;

  for (y = 0; y < 256; ++y) {
    for (i = 0; i < 8; ++i) {
      // set sprite color
      *(currentCopperlist++) = custom_color + 32 + (
        // sprite color group
        (i / 2) * 4 +
        // 0 is transparent
        1 +
        i % 2
      ) * 2;
      *(currentCopperlist++) = *(currentSpriteCopperlist++);

      // set sprite position
      *(currentCopperlist++) = custom_sprite_control + i * 8;
      *(currentCopperlist++) = *(currentSpriteCopperlist++);

      *(currentCopperlist++) = custom_sprite_control + i * 8 + 2;
      *(currentCopperlist++) = *(currentSpriteCopperlist++);
    }

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

    *(currentCopperlist++) = 1 + ((31 + (256 / 4)) << 1) + ((44 + y) << 8);
    *(currentCopperlist++) = 0xFFFE;
  }

  endCopperlist(currentCopperlist);

  takeOverSystem();

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

  i = 0;

  while (1) {
    swapCurrentScreenBuffer(&screenSetup, &currentScreen);

    clearCurrentBuns(&bunRenderer);

    renderBunFrame(i, &bunRenderer);

    renderTopaz();

    updateDisplayInCopperList(
      &screenSetup,
      &currentScreen,
      copperlistBitplanePointers
    );

    WaitBOF(250);

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

    i++;
    i %= FRAMES_FOR_SCREEN;
  }

  giveBackSystem();

  teardownScreen(&screenSetup);

  freeCopperlist(copperlist);

  teardownBunRenderer();

  return 0;
}