84 lines
2.6 KiB
Markdown
84 lines
2.6 KiB
Markdown
## Description
|
|
|
|
`sokol` is a thin wrapper around [sokol](https://github.com/floooh/sokol),
|
|
which in turn is a library of "Simple STB-style cross-platform libraries
|
|
for C and C++, written in C.", that provide access to graphics/audio/input
|
|
processing.
|
|
|
|
Each `.h` file in the sokol source code is well-documented as can be seen here:
|
|
|
|
[sokol_audio.h](https://github.com/floooh/sokol/blob/master/sokol_audio.h)
|
|
|
|
## Example from `@VEXEROOT/examples/sokol/sounds/simple_sin_tones.v`
|
|
|
|
```v cgen
|
|
import time
|
|
import math
|
|
import sokol.audio
|
|
|
|
const sw = time.new_stopwatch()
|
|
const sw_start_ms = sw.elapsed().milliseconds()
|
|
|
|
@[inline]
|
|
fn sintone(periods int, frame int, num_frames int) f32 {
|
|
return math.sinf(f32(periods) * (2 * math.pi) * f32(frame) / f32(num_frames))
|
|
}
|
|
|
|
fn my_audio_stream_callback(buffer &f32, num_frames int, num_channels int) {
|
|
ms := sw.elapsed().milliseconds() - sw_start_ms
|
|
unsafe {
|
|
mut soundbuffer := buffer
|
|
for frame := 0; frame < num_frames; frame++ {
|
|
for ch := 0; ch < num_channels; ch++ {
|
|
idx := frame * num_channels + ch
|
|
if ms < 250 {
|
|
soundbuffer[idx] = 0.5 * sintone(20, frame, num_frames)
|
|
} else if ms < 300 {
|
|
soundbuffer[idx] = 0.5 * sintone(25, frame, num_frames)
|
|
} else if ms < 1500 {
|
|
soundbuffer[idx] *= sintone(22, frame, num_frames)
|
|
} else {
|
|
soundbuffer[idx] = 0.5 * sintone(25, frame, num_frames)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
fn main() {
|
|
audio.setup(
|
|
stream_cb: my_audio_stream_callback
|
|
)
|
|
time.sleep(2000 * time.millisecond)
|
|
audio.shutdown()
|
|
}
|
|
```
|
|
|
|
## Troubleshooting sokol apps
|
|
|
|
A common problem, if you draw a lot of primitive elements in the same frame,
|
|
is that there is a chance that your program can exceed the maximum
|
|
allowed amount of vertices and commands, imposed by `sokol`.
|
|
|
|
The symptom is that your frame will be suddenly black, after it
|
|
becomes more complex.
|
|
|
|
Sokol's default for vertices is 131072.
|
|
Sokol's default for commands is 32768.
|
|
|
|
To solve that, you can try adding these lines at the top of your program:
|
|
`#flag -D_SGL_DEFAULT_MAX_VERTICES=4194304`
|
|
`#flag -D_SGL_DEFAULT_MAX_COMMANDS=65536`
|
|
You can see an example of that in:
|
|
https://github.com/vlang/v/blob/master/examples/gg/examples/gg/many_thousands_of_circles_overriding_max_vertices.v
|
|
|
|
Another approach to that problem, is to draw everything yourself in a streaming
|
|
texture, then upload that streaming texture as a single draw command to the GPU.
|
|
You can see an example of that done in:
|
|
https://github.com/vlang/v/blob/master/examples/gg/random.v
|
|
and in:
|
|
https://github.com/vlang/v/blob/master/examples/gg/random_stars.v
|
|
|
|
A third approach, is to only upload your changing inputs to the GPU, and do all
|
|
the calculations and drawing there in shaders.
|