python - How do I rotate an isometric camera around the screen center? -

i have tile-based project game, got nice pseudo-3d effect using multiple tile layers, able rotate camera (essentially, rotating sprites).

but, rotating sprites isn't equal rotating world, right?

by that, got to:

x = (x - y) * (tile_width/2); y = (x + y) * (tile_width/2); 

but, see? works 45 degree rotated tiles! how can modify angle used in formulas (or maybe better, more appropriate one)?

rotating sprites part of rotating world/camera.

to rotate world/camera, each tile needs moved along arc, , rotated @ same time. need use polar coordinates. compute distance , angle center-of-rotation center of each tile. add desired angle-of-rotation polar angle each tile. compute new x , y values center of tile converting cartesian coordinates.

here's code might like, assuming each tile represented struct, , struct has original x , y coordinates of center of tile (i.e. coordinates of center of tile when world not rotated).

    // compute distance center of tile center of rotation     double dx = tile[t].x - centerofrotation.x;     double dy = tile[t].y - centerofrotation.y;      // compute new location of tile in polar coordinates relative center of rotation     double r = sqrt(dx*dx + dy*dy);     double angle = atan2(dy, dx) + angleofrotation;      // compute display location tile     x = centerofrotation.x + r * cos(angle);     y = centerofrotation.y + r * sin(angle);      // note tile needs rotated well, using angleofrotation     // also, angles in radians 

when attempting rotate graphics, helps keep things simple. use small number of tiles, make tiles different colors strong borders, , identifying mark show orientation. here's example 9 tiles in initial orientation , rotated 30 degrees counter-clockwise.

here examples of can go wrong:
1) moving tiles without rotating tiles

2) rotating tiles without moving tiles

3) rotating tiles clockwise while moving tiles counter-clockwise

bottom line: pretty mistake result in image gaps.