269 lines
6.8 KiB
C
269 lines
6.8 KiB
C
#include <genesis.h>
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#include "sinTable.h"
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#include "cosTable.h"
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#define TABLE_LENGTH 720
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#define SPEED 5
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#define FRAC_BITS 8
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#define TILE_WIDTH 8
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#define TILE_HEIGHT 8
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#define TILE_SIZE (TILE_WIDTH * TILE_HEIGHT / 2)
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#define SCREEN_WIDTH 320
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#define SCREEN_HEIGHT 224
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#define SCREEN_TILES_X 40
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#define SCREEN_TILES_Y 28
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#define TILE_EMPTY 0
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#define TILE_FILLED 1
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#define MAP_WIDTH 10
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#define MAP_HEIGHT 10
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Line l;
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s16 angle = 0;
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s16 x, y;
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u8 tileBuffer[TILE_SIZE];
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u16 tileIndex = 0;
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const u8 map[10][10] = {{1,1,1,1,1,1,1,1,1,1},
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{1,0,0,0,0,0,0,0,0,1},
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{1,1,1,1,0,0,1,1,1,1},
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{1,0,0,1,0,0,1,0,0,1},
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{1,0,0,0,0,0,1,0,0,1},
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{1,0,0,1,0,0,1,1,0,1},
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{1,1,1,1,0,0,1,0,0,1},
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{1,0,0,0,0,0,0,0,0,1},
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{1,0,0,0,0,0,1,0,0,1},
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{1,1,1,1,1,1,1,1,1,1}};
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int dist(int ax, int ay, int bx, int by){
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return (ax-bx)*(ax-bx) + (ay-by)*(ay-by);
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}
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void castRay(s16 angle){
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if(angle >= 360) angle = angle - 360;
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if(angle < 0) angle = 360 + angle;
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u16 r,mx,my,mp,dof;
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s16 rx,ry,ra,xo,yo;
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s16 dy = sinTable[angle << 1];
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s16 dx = cosTable[angle << 1];
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s16 tan = 0;
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if(dx != 0) tan = (dy << FRAC_BITS)/dx;
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s16 aTan = 0;
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if(tan != 0) aTan = -(1 << (FRAC_BITS*2))/tan;
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s16 threshold = (20 << FRAC_BITS);
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if(aTan > threshold){
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aTan = threshold;
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}
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if(aTan < -threshold){
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aTan = -threshold;
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}
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dof = 0;
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s16 distH = 30000;
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s16 hx = l.pt1.x << FRAC_BITS;
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s16 hy = l.pt1.y << FRAC_BITS;
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if(dy == 0){
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rx = l.pt1.x << FRAC_BITS;
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ry = l.pt1.y << FRAC_BITS;
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dof = 8;
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}else {
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if(angle > 180) {
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ry = ((l.pt1.y / 10 * 10)-1) << FRAC_BITS;
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rx = (((l.pt1.y - (ry >> FRAC_BITS))*aTan)) + (l.pt1.x << FRAC_BITS);
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yo = -(10 << FRAC_BITS);
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xo = ((-yo >> FRAC_BITS)*aTan);
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}
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if(angle < 180) {
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ry = ((l.pt1.y / 10 * 10)+10) << FRAC_BITS;
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rx = (((l.pt1.y - (ry >> FRAC_BITS))*aTan)) + (l.pt1.x << FRAC_BITS);
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yo = 10 << FRAC_BITS;
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xo = (-(yo >> FRAC_BITS)*aTan);
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}
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}
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while(dof<8){
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mx = (rx >> FRAC_BITS) / 10;
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my = (ry >> FRAC_BITS) / 10;
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if(rx < 0 || ry < 0){
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dof = 8;
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continue;
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}
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if(mx < 10 && my < 10 && map[my][mx] == 1){
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dof = 8;
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hx = rx;
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hy = ry;
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distH = dist(l.pt1.x, l.pt1.y, rx >> FRAC_BITS, ry >> FRAC_BITS);
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}else{
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rx = rx + xo;
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ry = ry + yo;
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dof += 1;
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}
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}
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dof = 0;
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s16 distV = 30000;
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s16 vx = l.pt1.x << FRAC_BITS;
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s16 vy = l.pt1.y << FRAC_BITS;
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s16 nTan = -tan;
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threshold = (20 << FRAC_BITS);
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if(nTan > threshold){
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nTan = threshold;
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}
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if(nTan < -threshold){
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nTan = -threshold;
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}
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if(angle > 90 && angle < 270) { // Facing Left
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rx = ((l.pt1.x / 10 * 10)-1) << FRAC_BITS;
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ry = (((l.pt1.x) - (rx >> FRAC_BITS))*nTan) + (l.pt1.y << FRAC_BITS);
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xo = -(10 << FRAC_BITS);
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yo = ((-xo >> FRAC_BITS)*nTan);
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}
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if(angle < 90 || angle > 270) { // Facing Right
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rx = ((l.pt1.x / 10 * 10)+10) << FRAC_BITS;
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ry = (((l.pt1.x) - (rx >> FRAC_BITS))*nTan) + (l.pt1.y << FRAC_BITS);
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xo = 10 << FRAC_BITS;
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yo = -(xo >> FRAC_BITS)*nTan;
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}
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if(dx == 0){
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rx = l.pt1.x << FRAC_BITS;
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ry = l.pt1.y << FRAC_BITS;
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xo = 0;
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yo = 0;
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dof = 8;
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}
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while(dof<8){
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mx = (rx >> FRAC_BITS) / 10;
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my = (ry >> FRAC_BITS) / 10;
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if(rx < 0 || ry < 0){
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dof = 8;
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continue;
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}
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if(mx < 10 && my < 10 && map[my][mx] == 1){
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dof = 8;
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vx = rx;
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vy = ry;
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distV = dist(l.pt1.x, l.pt1.y, rx >> FRAC_BITS, ry >> FRAC_BITS);
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}else{
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rx = rx + xo;
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ry = ry + yo;
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dof += 1;
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}
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}
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if(distV < distH){
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l.pt2.x = vx >> FRAC_BITS;
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l.pt2.y = vy >> FRAC_BITS;
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}else {
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l.pt2.x = hx >> FRAC_BITS;
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l.pt2.y = hy >> FRAC_BITS;
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}
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}
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void initTileBuffer(u8 color) {
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u8 colorValue = (color << 4) | color; // Color for both nibbles
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for (int i = 0; i < TILE_SIZE; i++) {
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tileBuffer[i] = colorValue;
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}
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}
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void uploadTileDataToVRAM(u16 vramTileIndex) {
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VDP_loadTileData(tileBuffer, vramTileIndex, 1, DMA); // Load 1 tile to VRAM
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}
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void mapscan() {
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u8 mapcolor = 12; // map color
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mapcolor |= mapcolor << 4;
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for (u8 x = 0; x < 10; x++) {
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for (u8 y = 0; y < 10; y++) {
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if (map[y][x] == 1) {
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// Draw a filled tile for the map block
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for (u8 px = 0; px < TILE_WIDTH; px++) {
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for (u8 py = 0; py < TILE_HEIGHT; py++) {
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setPixelInBuffer(px, py, mapcolor);
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}
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}
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// Upload the filled tile to VRAM
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uploadTileDataToVRAM(tileIndex);
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VDP_setTileMapXY(VDP_BG_A, tileIndex, x, y);
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}
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}
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}
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}
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void clearScreenWithTile(u16 tileIndex) {
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// Fill the entire screen with the background tile
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VDP_fillTileMapRect(BG_A, TILE_ATTR_FULL(PAL1, 0, FALSE, FALSE, tileIndex), 0, 0, SCREEN_TILES_X, SCREEN_TILES_Y);
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}
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void drawMap() {
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for (u16 y = 0; y < MAP_HEIGHT; y++) {
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for (u16 x = 0; x < MAP_WIDTH; x++) {
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u8 tileType = map[y][x] ? TILE_FILLED : TILE_EMPTY;
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VDP_setTileMapXY(BG_A, TILE_ATTR_FULL(PAL1, 0, FALSE, FALSE, tileType), x, y);
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}
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}
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}
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void render() {
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clearScreenWithTile(TILE_EMPTY);
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drawMap();
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VDP_setTextPlane(BG_B);
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VDP_setTextPalette(2);
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VDP_showFPS(1);
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for(int i = 0; i < 50; i++){
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castRay(10);
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}
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SYS_doVBlankProcess();
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}
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void update() {
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u16 joy = JOY_readJoypad(JOY_1);
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if (joy & BUTTON_LEFT) {
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angle -= 1;
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}
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if (joy & BUTTON_RIGHT) {
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angle += 1;
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}
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if (joy & BUTTON_UP) {
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s16 ind = (int)((float)angle / 360.0f * 1024.0f);
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fix16 dy = sinFix16(ind);
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fix16 dx = cosFix16(ind);
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y += fix16ToInt(fix16Mul(dy, FIX16(SPEED)));
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x += fix16ToInt(fix16Mul(dx, FIX16(SPEED)));
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}
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if (joy & BUTTON_DOWN) {
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s16 ind = (int)((float)angle / 360.0f * 1024.0f);
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fix16 dy = sinFix16(ind);
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fix16 dx = cosFix16(ind);
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y -= fix16ToInt(fix16Mul(dy, FIX16(SPEED)));
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x -= fix16ToInt(fix16Mul(dx, FIX16(SPEED)));
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}
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}
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void initVDP() {
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SYS_disableInts();
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VDP_setPlaneSize(64, 32, TRUE);
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SYS_enableInts();
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}
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int main() {
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SYS_disableInts();
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VDP_setPlaneSize(64, 32, TRUE);
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SYS_enableInts();
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PAL_setColor(14, RGB24_TO_VDPCOLOR(0x0000ff));
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PAL_setColor(15, RGB24_TO_VDPCOLOR(0xff0000));
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VDP_setBackgroundColor(14);
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// Initialize and upload tile data for TILE_EMPTY and TILE_FILLED
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initTileBuffer(12); // Color for TILE_FILLED
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VDP_loadTileData(tileBuffer, TILE_FILLED, 1, DMA);
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initTileBuffer(0); // Color for TILE_EMPTY
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VDP_loadTileData(tileBuffer, TILE_EMPTY, 1, DMA);
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while (TRUE) {
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render();
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}
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return 0;
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} |