247 lines
5.7 KiB
C
247 lines
5.7 KiB
C
#include <genesis.h>
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#define SPEED 5
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Line l;
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s16 angle = 0;
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s16 x, y;
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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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fix16 rx,ry,ra,xo,yo;
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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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fix16 tan = FIX16(0);
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if(dx != 0) tan = fix16Div(dy, dx);
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fix16 aTan = FIX16(0);
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if(tan != 0) aTan = fix16Div(FIX16(-1), tan);
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s16 tanInt = fix16ToInt(fix16Mul(aTan, FIX16(100)));
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dof = 0;
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fix16 distH = FIX16(500);
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fix16 hx = FIX16(l.pt1.x);
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fix16 hy = FIX16(l.pt1.y);
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if(dy == 0){
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rx = FIX16(l.pt1.x);
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ry = FIX16(l.pt1.y);
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dof = 8;
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}else {
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if(angle > 180) {
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ry = FIX16(l.pt1.y / 10 * 10)-FIX16(1);
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rx = fix16Mul(FIX16(l.pt1.y) - ry,aTan) + FIX16(l.pt1.x);
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yo = FIX16(-10);
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xo = fix16Mul(0-yo,aTan);
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}
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if(angle < 180) {
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ry = FIX16((l.pt1.y / 10 * 10)+10);
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rx = fix16Mul(FIX16(l.pt1.y) - ry,aTan) + FIX16(l.pt1.x);
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yo = FIX16(10);
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xo = fix16Mul(0-yo,aTan);
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}
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}
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while(dof<8){
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mx = fix16ToInt(rx) / 10;
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my = fix16ToInt(ry) / 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, fix16ToInt(rx), fix16ToInt(ry));
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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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fix16 distV = FIX16(500);
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fix16 vx = FIX16(l.pt1.x);
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fix16 vy = FIX16(l.pt1.y);
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float nTan = 0-tan;
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if(angle > 90 && r < 270) {
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rx = FIX16(l.pt1.x / 10 * 10)-FIX16(1);
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ry = fix16Mul(FIX16(l.pt1.x) - rx,nTan) + FIX16(l.pt1.y);
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xo = FIX16(-10);
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yo = fix16Mul(0-xo,nTan);
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}
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if(angle < 90 || angle > 270) {
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rx = FIX16((l.pt1.x / 10 * 10)+10);
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ry = fix16Mul(FIX16(l.pt1.x) - rx,nTan) + FIX16(l.pt1.y);
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xo = FIX16(10);
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yo = fix16Mul(0-xo,nTan);
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}
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if(dx == 0){
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rx = FIX16(l.pt1.x);
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ry = FIX16(l.pt1.y);
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xo = FIX16(0);
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yo = FIX16(0);
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dof = 8;
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}
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while(dof<8){
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mx = fix16ToInt(rx) / 10;
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my = fix16ToInt(ry) / 10;
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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, fix16ToInt(rx), fix16ToInt(ry));
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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 = fix16ToInt(vx);
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l.pt2.y = fix16ToInt(vy);
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}else {
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l.pt2.x = fix16ToInt(hx);
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l.pt2.y = fix16ToInt(hy);
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}
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}
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void mapscan(){
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u8 mapcolor = 12;
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mapcolor |= mapcolor << 4;
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int mapscale = 10;
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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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Vect2D_s16 mapverts[4] = {{x*mapscale,y*mapscale},{(x+1)*mapscale,y*mapscale},{(x+1)*mapscale,(y+1)*mapscale},{x*mapscale,(y+1)*mapscale}};
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BMP_drawPolygon(mapverts, 4, mapcolor);
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}
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}
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}
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}
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void render(){
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l.pt1.x = x / 10;
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l.pt1.y = y / 10;
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//Clear the bitmap
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BMP_clear();
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//Draw the line defined above (in the background, hidden)
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mapscan();
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if(angle >= 360) angle = angle - 360;
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if(angle < 0) angle = 360 + angle;
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castRay(angle-20);
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BMP_drawLine(&l);
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castRay(angle-10);
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BMP_drawLine(&l);
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castRay(angle);
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BMP_drawLine(&l);
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castRay(angle+10);
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BMP_drawLine(&l);
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castRay(angle+20);
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BMP_drawLine(&l);
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BMP_showFPS(0);
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//Flip the data to the screen - i.e. actually draw the complete image on screen
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BMP_flip(1);
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//Increment the destination y coordinate
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//l.pt2.y = l.pt2.y + 2;
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//Reset the destination y coordinate if it hits 160
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//if (l.pt2.y == 160)
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//{
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//l.pt2.y = 0;
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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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//l.pt1.x -= SPEED;
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angle -= 1;
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}
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if(joy & BUTTON_RIGHT) {
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//l.pt1.x += SPEED;
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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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{
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x = 150;
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y = 150;
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initVDP();
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//Initialise the bitmap engine
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BMP_init(FALSE, BG_A, PAL0, FALSE);
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//Set the colour of the line. We are using pallete 0 for the bitmap, so we have 0->15. 15 is used for white text, so we set an unused pallet colour, 14 to blue - RGB 0000FF.
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u16 colour_blue = RGB24_TO_VDPCOLOR(0x0000ff);
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u16 colour_red = RGB24_TO_VDPCOLOR(0x756a4a);
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PAL_setColor(14, colour_blue);
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PAL_setColor(13, colour_red);
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PAL_setColor(12, RGB24_TO_VDPCOLOR(0x00ff00));
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PAL_setColor(15, RGB24_TO_VDPCOLOR(0xff0000));
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VDP_setBackgroundColor(13);
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//A line needs a source coordinate x,y and a destination coordinate x,y along with a pallete colour.
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l.pt1.x = 15;
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l.pt1.y = 15;
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l.pt2.x = 255;
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l.pt2.y = 0;
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l.col = 14;
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l.col |= l.col << 4; // if we do not left shift the colour, we get gaps in the line
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while(TRUE)
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{
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render();
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update();
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}
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return 0;
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} |