Ndtyjky

Everybody i had implemented this raycasting engine tutorial https://www.instructables.com/id/Making-a-Basic-3D-Engine-in-Java/
succesfully.

It seems to be based in the lode vandevenne tutorial from this site:

https://lodev.org/cgtutor/raycasting2.html

From the last site i had implemented all the code for floor and celling, rename the variables to match my own (the code is almost the same).
But when i try to "send" my floor texture image information to pixels(the buffer) so it can be rendered, i had a difficulty:

in the original code, this buffer is a matrix[x][y] but i my new code, is a single array. See this is the original:

buffer[y][x] = (texture[3][texWidth * floorTexY + floorTexX] >> 1) & 8355711;

this is my code:

int flColor = textures.get(flNum).pixels[floorTexY + floorTexX];

pixels [x + y * (width)] = flColor;

i get the texture "id", then pixel information(the problematic part), save it to int flColor, and then send it to pixels array.(with some x / y gibberish).

it is suppose i had just to multiply x * y for get the whole texture information, since is a square. But if i do that, i get an arrayoutofbounds error. Should i forget this approach and try to get a matrix based buffer instead?

HERE Is my whole floor casting source code:

//FLOOR CASTING HERE? lode vandevenne tutorial...

                    double floorXWall, floorYWall; //x,y position of the 

                    floor texel at the bottom of the wall

                    // 4 different wall directions possible

                    if(side == 0 && rayDirX > 0)

                    {

                        floorXWall = mapX;

                        floorYWall = mapY + wallX;

                    }

                    else if(side == 0 && rayDirX < 0)

                    {

                      floorXWall = mapX + 1.0;

                      floorYWall = mapY + wallX;

                    }

                    else if(side == 1 && rayDirY > 0)

                    {

                      floorXWall = mapX + wallX;

                      floorYWall = mapY;

                    }

                    else

                    {

                      floorXWall = mapX + wallX;

                      floorYWall = mapY + 1.0;

                    }



                    double distWall, distPlayer, currentDist;



                    distWall = perpWallDist; // The distance from player to the first wall the ray hit

                    distPlayer = 0.0;



                    if (drawEnd < 0) drawEnd = height; //becomes < 0 when the integer overflows. height = screen height.



                    //draw the floor from drawEnd to the bottom of the screen

                    for(int y = drawEnd + 1; y < height; y++)

                    {

                      currentDist = height / (2.0 * y - height); //you could make a small lookup table for this instead



                      double weight = (currentDist - distPlayer) / (distWall - distPlayer);



                      double currentFloorX = weight * floorXWall + (1.0 - weight) * camera.xPos;//posX;

                      double currentFloorY = weight * floorYWall + (1.0 - weight) * camera.yPos;//posY;



                      int floorTexX, floorTexY;

                      floorTexX = (int)((currentFloorX * width) % width);

                      floorTexY = (int)((currentFloorY * height) % height);



                      // floor         

                      // buffer[y][x] = (texture[3][texWidth * floorTexY + floorTexX] >> 1) & 8355711;

                         int flColor = textures.get(flNum).pixels[floorTexY - floorTexX];

                         pixels [x + y * (width)]  = flColor;



                      // ceiling (symmetrical!)

                      // buffer[h - y][x] = texture[6][texWidth * floorTexY + floorTexX];







                    } //FLOOR AND CEILING END