TK2048/src/vdgam_main.c

#include <stubs.h>
#include <string.h>

#include <calypsi/intrinsics6502.h>

#include "vdp_utils.h"
#include "game_vdp_graphics.h"

#include "monitor_subroutines.h"
#include "utility.h"
#include "mem_map.h"
#include "mem_registers.h"
#include "shared_page.h"
#include "state_page.h"
#include "dlog_data.h"
#include "game_data.h"
#include "input.h"
#include "game_logic.h"
#include "monitor_subroutines.h"
#include "sound.h"
#include "module_list.h"

// External initialization requirements
#pragma require __preserve_zp
#pragma require __data_initialization_needed

#define HSCORE_TEXT_X	27
#define HSCORE_TEXT_Y	13

#define SCORE_TEXT_X	27
#define SCORE_TEXT_Y	4

#define MOVES_TEXT_X	27
#define MOVES_TEXT_Y	8

#define BOTTOM_TEXT_X	1
#define BOTTOM_TEXT_Y	23

#define WIN_SCORE_BONUS 10000

static state_page_data* state_page = (state_page_data*)STATE_PAGE;
static shared_page_data *shared_page = (shared_page_data*)SHARED_PAGE;
static uint8_t text_buf[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };

void main(void) {
	uint16_t moves_count = 0;
	uint16_t score = 0;
	int8_t done = 0;
	
	__disable_interrupts();	// Make sure the interrupts are disabled
	
	// By default, once we return from this, return to the DLOG module and give the master no command to execute
	shared_page->master_command = MASTER_COMMAND_NONE;
	shared_page->next_module_idx = MODULE_DLOG_VDP; // Go to the dialog module
	
	dlog_data *dld = (dlog_data *)(shared_page->module_data);
	dlog_data *gad = (dlog_data *)(shared_page->module_data);

	// Make sure the buffers are pointing to the correct memory and are clear
	vdp_hide_sprites();
	vdp_clear_gamegrid();
	vdp_switch_nt(0); // Make sure VDP shows the gamegrid

	// Setup the IRQ handler
	POKEW(IRQ_HANDLER_ADDRESS, (uint16_t)vdp_irq_handler);

	// Reset the game, calculate the initial score depending on which tiles we randomly get
	score = reset_game();
	
	// Load the game
	if(gad->mode == GAME_MODE_LOAD) {
		gad->mode = GAME_MODE_NORMAL;
		
		memcpy(get_front_grid(), (void*)(state_page->save_grid), GRID_SIDE * GRID_SIDE);
		moves_count = state_page->saved_moves_count;
		score = calculate_score();
		
		// We loaded an empty save, just restart the game
		if (!score) score = reset_game();
	}

	// Draw the initial state of the game
	vdp_print_string(0, BOTTOM_TEXT_X, BOTTOM_TEXT_Y, "hkz@social.chinwag.org     2025");	
	
	num_to_decbuf(state_page->hi_score, 5, text_buf); // High score
	decbuf_to_ascii(5, text_buf);
	vdp_print_string(0, HSCORE_TEXT_X, HSCORE_TEXT_Y, (char*)text_buf);	
	
	num_to_decbuf(moves_count, 5, text_buf); // Moves count
	decbuf_to_ascii(5, text_buf);
	vdp_print_string(0, MOVES_TEXT_X, MOVES_TEXT_Y, (char*)text_buf);	
	
	num_to_decbuf(score, 5, text_buf); // Score
	decbuf_to_ascii(5, text_buf);
	vdp_print_string(0, SCORE_TEXT_X, SCORE_TEXT_Y, (char*)text_buf);
	
	vdp_draw_joystick(JS_POS_CENTER); // Center the joystick
	
	vdp_redraw_tiles(get_front_grid());
	
	__enable_interrupts();

	while(1) { // Game loop
		lfsr_update();
		
		__disable_interrupts();
		switch(read_kb()) {
			case K_UP:
				SND_TAP();
				vdp_draw_joystick(JS_POS_UP);
				done = step_game(GAME_STEP_UP);
				break;
			case K_DOWN:
				SND_TAP();
				vdp_draw_joystick(JS_POS_DOWN);
				done = step_game(GAME_STEP_DOWN);
				break;
			case K_LEFT:
				SND_TAP();
				vdp_draw_joystick(JS_POS_LEFT);
				done = step_game(GAME_STEP_LEFT);
				break;
			case K_RIGHT:
				SND_TAP();
				vdp_draw_joystick(JS_POS_RIGHT);
				done = step_game(GAME_STEP_RIGHT);
				break;
			case K_CTRL_R:
				snd_mod_button();
				
				score = 0; // We'll reset the score
				done = -1;
				break;
			case K_CTRL_S: // The following two will return early
				snd_mod_button();

				memcpy((void*)(state_page->save_grid), get_front_grid(), GRID_SIDE * GRID_SIDE);
				state_page->saved_moves_count = moves_count;
				shared_page->master_command = MASTER_COMMAND_SAVE;
			case K_CTRL_L:
				snd_mod_button();

				shared_page->next_module_idx = MODULE_GAME_VDP;
				gad->mode = GAME_MODE_LOAD;
				return;
			default:
				__enable_interrupts();
				continue; // Do nothing, loop again
		}
			
		// Increase the count of moves we made (unless we lost or reset the game)
		if(done >= 0) moves_count++;
				
		num_to_decbuf(moves_count, 5, text_buf); // Moves count
		decbuf_to_ascii(5, text_buf);
		vdp_print_string(0, MOVES_TEXT_X, MOVES_TEXT_Y, (char*)text_buf);		
			
		// If we have won, or we got a reset request, break out of this loop
		if(done) {
			score += (done > 0) ? WIN_SCORE_BONUS : 0;
			
			num_to_decbuf(score, 5, text_buf); // Score
			decbuf_to_ascii(5, text_buf);
			vdp_print_string(0, SCORE_TEXT_X, SCORE_TEXT_Y, (char*)text_buf);
			
			break;
		}
			
		// Unable to add a tile: we ran out of space and lost!!!
		uint8_t random_tile_off = add_random_tile();
		if(!random_tile_off) {
			done = -1; // Lost the game
			break;
		}
			
		score = calculate_score();
			
		// Draw the score
		num_to_decbuf(score, 5, text_buf); // Score
		decbuf_to_ascii(5, text_buf);
		vdp_print_string(0, SCORE_TEXT_X, SCORE_TEXT_Y, (char*)text_buf);
		vdp_redraw_tiles(get_front_grid());
		vdp_draw_joystick(JS_POS_CENTER);
		
		__enable_interrupts();
	}
	
	dld->mode = (done > 0) ? DLOG_MODE_WIN : DLOG_MODE_LOSE;
	dld->score = score;

	vdp_redraw_tiles(get_front_grid());

	WAIT(0xFF);

	__disable_interrupts();

	return; 
}