/*
 *      Copyright (c) 2024 Scott Duensing, scott@kangaroopunch.com
 *
 *      Permission is hereby granted, free of charge, to any person obtaining a copy
 *      of this software and associated documentation files (the "Software"), to deal
 *      in the Software without restriction, including without limitation the rights
 *      to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 *      copies of the Software, and to permit persons to whom the Software is
 *      furnished to do so, subject to the following conditions:
 *
 *      The above copyright notice and this permission notice shall be included in
 *      all copies or substantial portions of the Software.
 *
 *      THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *      IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *      FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 *      AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 *      LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 *      OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 *      SOFTWARE.
 */


#include "a23d2.h"

#include <string.h>  // For memcopy


volatile cameraT   *_camera = (cameraT *)CAMERA_SHARED_START; // Simulation copy of camera.
volatile cameraT   *_cameraInDatabase;
volatile byte      *_pointer;

uint16_t   _drawlist;
uint16_t   _drawlistInDatabase;

uint16_t   _bytes;
uint8_t    _x1;
uint8_t    _y1;
uint8_t    _x2;
uint8_t    _y2;
bool       _useColor;
byte       _mmu;
byte       _ram;
//float      _trig;


#define SEGMENT_A23D2


// There's a lot of global use in here.  We can't use the virtual stack.


#if 0
void a23d2Cos(void) {
	// We need to manually page 0x54000 into 0x6000.
	// This isn't actually large enough for A2-3D2 but what we should only
	// lose Apple ][ stuff we're not using anyway.
	POKE(MMU_MEM_BANK_3, A23D2_FAR_BLOCK);

	// Map 0-359 into 0-255.
	_tdata = _tdata % 359;
	_y1 = (360/256) * _tdata;

	// Call COSEX.
	POKE(A23D2_TDATA, _y1);
	__attribute__((leaf)) asm volatile("jsr %[addy]":: [addy] "i"(A23D2_COSEX));

	// Convert to float.
	_trig = (float)PEEKW(A23D2_TDATA) / 32768;

	// Restore memory map.
	POKE(MMU_MEM_BANK_3, 3);
}
#endif


void a23d2Draw(void) {

	_pointer = (byte *)_drawlist;

	// Move our 3D/2D data buffer at 0x56000 into slot 4.
	POKE(MMU_MEM_BANK_4, DATABASE_FAR_BLOCK);

	while (true) {
		switch (*_pointer++) {

			// Line.
			case (byte)LIN2D:
				_x1  = (uint8_t)((int8_t)(*_pointer++) + 128);
				_y1  = 255 - (uint8_t)((int8_t)(*_pointer++) + 128);
				_x2 = (uint8_t)((int8_t)(*_pointer++) + 128);
				_y2 = 255 - (uint8_t)((int8_t)(*_pointer++) + 128);
				bitmapLine(_x1, _y1, _x2, _y2);
				continue;

			// Point.
			case (byte)PNT2D:
				_x1  = (uint8_t)((int8_t)(*_pointer++) + 128);
				_y1  = 255 - (uint8_t)((int8_t)(*_pointer++) + 128);
				bitmapPutPixel(_x1, _y1);
				continue;

			// Set Color.
			case (byte)STCOL:
				_x1 = (int8_t)(*_pointer++);
				if (_useColor) bitmapSetColor(_x1);
				continue;

			// Set Resolution.
			case (byte)SRES:
				// Eat this byte.  We don't need it.
				_pointer++;
				continue;

			// End.
			case (byte)END:
				break;

		}
		break;
	}

	// Restore memory map.
	POKE(MMU_MEM_BANK_4, 4);
}


void a23d2Init(void) {
	// We need to manually page 0x54000 into 0x6000.
	// This isn't actually large enough for A2-3D2 but what we should only
	// lose Apple ][ stuff we're not using anyway.
	POKE(MMU_MEM_BANK_3, A23D2_FAR_BLOCK);

	// We're going to clobber from 0x80fb to 0x8101 with our setup database.
	// Usually we'd swap in bank 4, but we'd have to save that, too.  Back it up.
	scdMemCpy((byte *)(SCRATCH_END - 0x06), (byte *)A23D2_TEST_DATABASE, 0x06);

	// Initialize A2-3D2 so we can use the "fast entry point" (NXTPT) when rendering.
	_bytes   = 0;
	_pointer = (byte *)A23D2_TEST_DATABASE;  // Standard location for test database in A2-3D2.
	_pointer[_bytes++] = SCRSZ;              // Screen size.  256x240.  Center is 0,0.
	_pointer[_bytes++] = 255;
	_pointer[_bytes++] = 239;
	_pointer[_bytes++] = 0;
	_pointer[_bytes++] = 0;
	_pointer[_bytes++] = END;                // Setup complete!

	// Save ZP that A2-3D2 is going to clobber.
	scdMemCpy((byte *)COMPILER_ZP_SAVE, (byte *)COMPILER_ZP_START, COMPILER_ZP_LENGTH);

	// Call ENTRYN.  This sets up A2-3D2.
	__attribute__((leaf)) asm volatile("jsr %[addy]":: [addy] "i"(A23D2_ENTRYN));

	// Save A2-3D2s ZP for later.
	scdMemCpy((byte *)A23D2_ZP_SAVE, (byte *)A23D2_ZP_START, A23D2_ZP_LENGTH);

	// Restore ZP that A2-3D2 clobbered.
	scdMemCpy((byte *)COMPILER_ZP_START, (byte *)COMPILER_ZP_SAVE, COMPILER_ZP_LENGTH);

	// Put back the RAM we clobbered.
	scdMemCpy((byte *)A23D2_TEST_DATABASE, (byte *)(SCRATCH_END - 0x06), 0x06);

	// Move our 3D/2D data buffer at 0x56000 into slot 4.
	POKE(MMU_MEM_BANK_4, DATABASE_FAR_BLOCK);

	// Set up drawlists.
	_drawlistInDatabase = DATABASE + 1;  // First value after ARRAY in near memory.
	POKE(DRAWLIST_P0, END);
	POKE(DRAWLIST_P1, END);

	// Set up camera.
   _cameraInDatabase = (cameraT *)(DATABASE + 4); // First value after EYE in near memory.
	_camera->x = _cameraInDatabase->x;
	_camera->y = _cameraInDatabase->y;
	_camera->z = _cameraInDatabase->z;
	_camera->p = _cameraInDatabase->p;
	_camera->b = _cameraInDatabase->b;
	_camera->h = _cameraInDatabase->h;

	// Restore memory map.
	POKE(MMU_MEM_BANK_4, 4);
	POKE(MMU_MEM_BANK_3, 3);
}


void a23d2Render(void) {
	// We need to manually page 0x54000 into 0x6000.
	// This isn't actually large enough for A2-3D2 but what we should only
	// lose Apple ][ stuff we're not using anyway.
	POKE(MMU_MEM_BANK_3, A23D2_FAR_BLOCK);

	// Move our 3D/2D data buffer at 0x56000 into slot 4.
	POKE(MMU_MEM_BANK_4, DATABASE_FAR_BLOCK);

	// Update drawlist.
	POKEW(_drawlistInDatabase, _drawlist);

	// Update camera position.
	_cameraInDatabase->x = _camera->x;
	_cameraInDatabase->y = _camera->y;
	_cameraInDatabase->z = _camera->z;
	_cameraInDatabase->p = _camera->p;
	_cameraInDatabase->b = _camera->b;
	_cameraInDatabase->h = _camera->h;

	// Save ZP that A2-3D2 is going to clobber.
	scdMemCpy((byte *)COMPILER_ZP_SAVE, (byte *)COMPILER_ZP_START, COMPILER_ZP_LENGTH);

	// Restore A2-3D2s ZP.
	scdMemCpy((byte *)A23D2_ZP_START, (byte *)A23D2_ZP_SAVE, A23D2_ZP_LENGTH);

	// Set IBP.
	POKEW(A23D2_IBP, DATABASE);

	// Call NXTPT.
	__attribute__((leaf)) asm volatile("jsr %[addy]":: [addy] "i"(A23D2_NXTPT) : "a","x","y","c","v");    // Call NXTPT.

	// Save A2-3D2s ZP for later.
	scdMemCpy((byte *)A23D2_ZP_SAVE, (byte *)A23D2_ZP_START, A23D2_ZP_LENGTH);

	// Restore ZP that A2-3D2 clobbered.
	scdMemCpy((byte *)COMPILER_ZP_START, (byte *)COMPILER_ZP_SAVE, COMPILER_ZP_LENGTH);

	// Restore memory map.
	POKE(MMU_MEM_BANK_4, 4);
	POKE(MMU_MEM_BANK_3, 3);
}


#if 0
void a23d2Sin(void) {
	// We need to manually page 0x54000 into 0x6000.
	// This isn't actually large enough for A2-3D2 but what we should only
	// lose Apple ][ stuff we're not using anyway.
	POKE(MMU_MEM_BANK_3, A23D2_FAR_BLOCK);

	// Map 0-359 into 0-255.
	_tdata = _tdata % 359;
	_y1 = (360/256) * _tdata;

	// Call SINEX.
	POKE(A23D2_TDATA, _y1);
	__attribute__((leaf)) asm volatile("jsr %[addy]":: [addy] "i"(A23D2_SINEX));

	// Convert to float.
	_trig = (float)PEEKW(A23D2_TDATA) / 32768;

	// Restore memory map.
	POKE(MMU_MEM_BANK_3, 3);
}
#endif