Timeline for Why did the NES not allow rotated sprites?
Current License: CC BY-SA 4.0
10 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jan 16, 2024 at 14:04 | history | edited | Omar and Lorraine | CC BY-SA 4.0 | added 11 characters in body |
| Jul 21, 2022 at 12:42 | history | edited | Omar and Lorraine | CC BY-SA 4.0 | added 4 characters in body |
| Jul 21, 2022 at 12:08 | history | edited | Omar and Lorraine | CC BY-SA 4.0 | added 79 characters in body |
| Nov 10, 2021 at 0:50 | comment | added | Owen Reynolds | Note that this is somewhat true today. Simple GPU settings can set tiling to x=-1 (horizontal flip) or y=-1 (vertical flip) or both (180 rotation). A 90 or 270 rotation requites playing with the matrixes. | |
| Nov 9, 2021 at 22:36 | comment | added | Ilmari Karonen | @NobodyNada: Exactly. If you need to rotate a sprite by 90°, the fast and easy solution is to make a set of pre-rotated bitmaps. Sure, it doubles the amount of ROM needed for the sprite, but that's the only cost, and I doubt that it would be breaking for most games that need it. And if you don't need it, you won't need to pay the cost. | |
| Nov 9, 2021 at 19:32 | comment | added | NobodyNada | One can imagine a more complex PPU design that could access memory in one cycle, or gradually loads sprite tiles over a period of 8 lines before they're needed -- but any method to rotate sprites would have greatly increased the cost and complexity of the PPU for very little benefit, and keeping costs down was extremely high-priority during the NES's development. | |
| Nov 9, 2021 at 19:32 | comment | added | NobodyNada | "I don't think there's enough time on this slow hardware to do that." There absolutely is not enough time. See the NESDev Wiki's frame timing description and diagram: each memory access takes 2 cycles, and there is only one idle cycle per scanline. So adding another 14 bytes * 2 bytes/cycle * 8 sprites per scanline = 224 cycles per scanline would certainly not be feasible. | |
| Nov 9, 2021 at 11:15 | vote | accept | Jojo | ||
| Nov 9, 2021 at 10:09 | history | edited | Omar and Lorraine | CC BY-SA 4.0 | added 87 characters in body |
| Nov 9, 2021 at 9:22 | history | answered | Omar and Lorraine | CC BY-SA 4.0 |