object_renderer.cc

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#include "app/zelda3/dungeon/object_renderer.h"
 
namespace yaze {
namespace app {
namespace zelda3 {
namespace dungeon {
 
void DungeonObjectRenderer::LoadObject(uint32_t routine_ptr,
                                       std::array<uint8_t, 16>& sheet_ids) {
  vram_.sheets = sheet_ids;
 
  rom_data_ = rom()->vector();
  // Prepare the CPU and memory environment
  memory_.Initialize(rom_data_);
 
  // Configure the object based on the fetched information
  ConfigureObject();
 
  // Run the CPU emulation for the object's draw routines
  RenderObject(routine_ptr);
}
 
void DungeonObjectRenderer::ConfigureObject() {
  cpu.A = 0x03D8;
  cpu.X = 0x03D8;
  cpu.DB = 0x7E;
  // VRAM target destinations
  cpu.WriteLong(0xBF, 0x7E2000);
  cpu.WriteLong(0xCB, 0x7E2080);
  cpu.WriteLong(0xC2, 0x7E2002);
  cpu.WriteLong(0xCE, 0x7E2082);
  cpu.SetAccumulatorSize(false);
  cpu.SetIndexSize(false);
}
 
void DungeonObjectRenderer::RenderObject(uint32_t routine_ptr) {
  cpu.PB = 0x01;
 
  // Push an initial value to the stack we can read later to confirm we are
  // done
  cpu.PushLong(0x01 << 16 | routine_ptr);
 
  int i = 0;
  while (true) {
    uint8_t opcode = cpu.ReadByte(cpu.PB << 16 | cpu.PC);
    cpu.ExecuteInstruction(opcode);
 
    i++;
  }
 
  UpdateObjectBitmap();
}
 
// In the underworld, this holds a copy of the entire BG tilemap for
// Layer 1 (BG2) in TILEMAPA
// Layer 2 (BG1) in TILEMAPB
void DungeonObjectRenderer::UpdateObjectBitmap() {
  tilemap_.reserve(0x2000);
  for (int i = 0; i < 0x2000; ++i) {
    tilemap_.push_back(0);
  }
  int tilemap_offset = 0;
 
  // Iterate over tilemap in memory to read tile IDs
  for (int tile_index = 0; tile_index < 512; tile_index++) {
    // Read the tile ID from memory
    int tile_id = memory_.ReadWord(0x7E2000 + tile_index);
    std::cout << "Tile ID: " << std::hex << tile_id << std::endl;
 
    int sheet_number = tile_id / 32;
    std::cout << "Sheet number: " << std::hex << sheet_number << std::endl;
 
    int row = tile_id / 8;
    int column = tile_id % 8;
 
    int x = column * 8;
    int y = row * 8;
 
    auto sheet = rom()->mutable_gfx_sheets()->at(vram_.sheets[sheet_number]);
 
    // Copy the tile from VRAM using the read tile_id
    sheet.Get8x8Tile(tile_id, x, y, tilemap_, tilemap_offset);
  }
 
  bitmap_.Create(256, 256, 8, tilemap_);
}
 
}  // namespace dungeon
}  // namespace zelda3
}  // namespace app
}  // namespace yaze