DimetricGeometry.java

package render.tile.geom;

public class DimetricGeometry implements Geometry {

    private static final int TILE_WIDTH = 64;
    private static final int TILE_HEIGHT = 31;

    @Override
    public void render(int centerX, int centerY, float screenWidth, float screenHeight, float screenOffsetX, float screenOffsetY, float zoomFactor, GeometryTileVisitor visitor) {
        final float actualHeight = TILE_HEIGHT * zoomFactor;
        final float actualWidth = TILE_WIDTH * zoomFactor;

        final int upTiles = (int) (screenHeight / 2 / actualHeight + 2 / zoomFactor) + 2;
        final int leftTiles = (int) (screenWidth / 2 / actualWidth + 2 / zoomFactor) + 2;

        // for the upper left corner
        final int diagonalTilesX = upTiles + leftTiles;
        final int diagonalTilesY = upTiles - leftTiles;

        screenOffsetX += screenWidth / 2; // Geolykt being lazy
        screenOffsetY += screenHeight / 2;

        int x = diagonalTilesX;
        int y = diagonalTilesY;
        int i = 0;

        while (x != -diagonalTilesY && y != -diagonalTilesX) {
            while (x != (diagonalTilesY - i + 1) && y != (diagonalTilesX - i + 1)) {
                // A strange little trick: By altering the render height here we can get some funky behaviour
                float renderX = screenOffsetX + (y - x) * (actualWidth / 2);
                float renderY = screenOffsetY + (y + x) * (actualHeight / 2);
                visitor.visit(centerX + x, centerY + y, renderX, renderY);
                x--;
                renderX = screenOffsetX + (y - x) * (actualWidth / 2);
                renderY = screenOffsetY + (y + x) * (actualHeight / 2);
                visitor.visit(centerX + x, centerY + y, renderX, renderY);
                y++;
            }
            x = diagonalTilesX - i;
            y = diagonalTilesY - i;
            i++;
        }
    }

    @Override
    public int getBaseTileRenderHeight() {
        return TILE_HEIGHT;
    }

    @Override
    public int getBaseTileRenderWidth() {
        return TILE_WIDTH;
    }

    @Override
    public void readjustScreenOffset() {
        float actualTileWidth = TILE_WIDTH * Game.zoomFactor;
        int moveLeft = (int) (Game.screenRenderOffsetX / actualTileWidth);
        Game.screenRenderOffsetX %= actualTileWidth;
        Game.rtileX += moveLeft;
        Game.rtileY -= moveLeft;

        float actualTileHeight = TILE_HEIGHT * Game.zoomFactor;
        int moveUp = (int) (Game.screenRenderOffsetY / actualTileHeight);
        Game.screenRenderOffsetY %= actualTileHeight;
        Game.rtileX -= moveUp;
        Game.rtileY -= moveUp;
    }
}