Compact bitmap animation

[fweiss]

Currently, bitmap animations are defined with std::vector<uint32_t>. This gobbles up memory. Indeed, have to compile with -Os.

We propose a color table model like that used in Felix. Use std::vector<uint8_t> or std::vector<uint16_t> along with a color table of uint32_t[]``.

Comverting existing data should be easy using search and replace.

[fweiss]

Size reduction log:

• baseline badge.bin binary size 0xdf9f0 bytes. Smallest app partition is 0x100000 bytes. 0x20610 bytes (13%) free.
• felix badge.bin binary size 0xdfbe0 bytes. Smallest app partition is 0x100000 bytes. 0x20420 bytes (13%) free.

The felix refactoring actually added 496 bytes. Maybe due to initialization via copy?

Switching from int16_t to uint8_t enum size didn't make a difference.

Let's try alphabet, we expect an improvement of about 20KB.

[fweiss]

Alphabet size:

badge.bin binary size 0xdfd70 bytes. Smallest app partition is 0x100000 bytes. 0x20290 bytes (13%) free.

That's an increase of 400 bytes. Was expecting a much greater reduction.

OK, changed the ColorIndex to int16_t
badge.bin binary size 0xdf5b0 bytes. Smallest app partition is 0x100000 bytes. 0x20a50 bytes (13%) free.

Ahh, reduction of 1584.

And then, take ColorIndex to uin8_t:
badge.bin binary size 0xdf180 bytes. Smallest app partition is 0x100000 bytes. 0x20e80 bytes (13%) free.

That reduced by 2556 (over the Felix)

[fweiss]

Outputting the assembly code by adding set_target_properties(${COMPONENT_LIB} PROPERTIES COMPILE_FLAGS "-save-temps=obj") to CMakeLists.txt. The result is Alphabet.cpp.s in the folder build/esp-idf/main/CMakeFiles.

But the initialization is weird. It's broken into chunks somehow.

[fweiss]

Using a static pixelIndexes[52][64]:
badge.bin binary size 0xdebb0 bytes. Smallest app partition is 0x100000 bytes. 0x21450 bytes (13%) free.

Reduction from Felix is 4144. Still expecting better. By reducing each pixel from 4 bytes to 1 byte saves 3 bytes. Over a total of 52 x 64 pixels, that should reduce by 9984

The assembly code does have .byte 0 for a count of 3328 (52*64)

[fweiss]

Using [][] instead of vector provides reduction, but not as much as theoretically possible. I think it's best to leave it at that for now. The main test would be if after turning of -Os, the program can fit.

[fweiss]

After refactoring dice animation:
badge.bin binary size 0xdea00 bytes. Smallest app partition is 0x100000 bytes. 0x21600 bytes (13%) free.
This is a reduction of 4576 over felix

With ColorIndex : uint16_t, size was 0xdeb80, with uint32_t, size was 0xdee70

[fweiss]

After refactoring EmojiAnimation:
badge.bin binary size 0xde020 bytes. Smallest app partition is 0x100000 bytes. 0x21fe0 bytes (13%) free.

Reduction over Felix was 7104

[fweiss]

Did not refactor all the animations becuse it got difficult. See #18. Did do the worst ones, Emoji and alphabet.