softbuffer/src/win32.rs

73 lines
2.1 KiB
Rust

use crate::{GraphicsContextImpl, SwBufError};
use raw_window_handle::Win32WindowHandle;
use std::os::raw::c_int;
use windows_sys::Win32::Foundation::HWND;
use windows_sys::Win32::Graphics::Gdi::{
StretchDIBits, BITMAPINFOHEADER, BI_BITFIELDS, RGBQUAD, HDC,
ValidateRect, GetDC, SRCCOPY, DIB_RGB_COLORS,
};
pub struct Win32Impl {
window: HWND,
dc: HDC,
}
// Wrap this so we can have a proper number of bmiColors to write in
// From minifb
#[repr(C)]
struct BitmapInfo {
pub bmi_header: BITMAPINFOHEADER,
pub bmi_colors: [RGBQUAD; 3],
}
impl Win32Impl {
pub unsafe fn new(handle: &Win32WindowHandle) -> Result<Self, crate::SwBufError> {
let dc = GetDC(handle.hwnd as HWND);
if dc == 0 {
return Err(SwBufError::PlatformError(Some("Device Context is null".into()), None));
}
Ok(
Self {
dc,
window: handle.hwnd as HWND,
}
)
}
}
impl GraphicsContextImpl for Win32Impl {
unsafe fn set_buffer(&mut self, buffer: &[u32], width: u16, height: u16) {
let mut bitmap_info: BitmapInfo = std::mem::zeroed();
bitmap_info.bmi_header.biSize = std::mem::size_of::<BITMAPINFOHEADER>() as u32;
bitmap_info.bmi_header.biPlanes = 1;
bitmap_info.bmi_header.biBitCount = 32;
bitmap_info.bmi_header.biCompression = BI_BITFIELDS;
bitmap_info.bmi_header.biWidth = width as i32;
bitmap_info.bmi_header.biHeight = -(height as i32);
bitmap_info.bmi_colors[0].rgbRed = 0xff;
bitmap_info.bmi_colors[1].rgbGreen = 0xff;
bitmap_info.bmi_colors[2].rgbBlue = 0xff;
StretchDIBits(
self.dc,
0,
0,
width as c_int,
height as c_int,
0,
0,
width as c_int,
height as c_int,
std::mem::transmute(buffer.as_ptr()),
std::mem::transmute(&bitmap_info),
DIB_RGB_COLORS,
SRCCOPY,
);
ValidateRect(self.window, std::ptr::null_mut());
}
}