somebar/src/shm_buffer.cpp

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2021-10-20 20:20:27 +02:00
// somebar - dwl bar
// See LICENSE file for copyright and license details.
#include <sys/mman.h>
#include <unistd.h>
#include "shm_buffer.hpp"
#include "common.hpp"
constexpr int n = 2;
ShmBuffer::ShmBuffer(int w, int h, wl_shm_format format)
: width(w)
, height(h)
, stride(w*4)
{
auto oneSize = stride*h;
_totalSize = oneSize * n;
auto fd = memfd_create("wl_shm", MFD_CLOEXEC);
ftruncate(fd, _totalSize);
auto pool = wl_shm_create_pool(shm, fd, _totalSize);
auto ptr = reinterpret_cast<char*>(mmap(nullptr, _totalSize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0));
close(fd);
for (auto i=0; i<n; i++) {
auto offset = oneSize*i;
auto buffer = wl_shm_pool_create_buffer(pool, offset, width, height, stride, format);
_buffers[i] = { ptr+offset, buffer };
}
wl_shm_pool_destroy(pool);
}
ShmBuffer::~ShmBuffer()
{
munmap(_buffers[0].data, _totalSize);
for (auto i=0; i<n; i++) {
wl_buffer_destroy(_buffers[i].buffer);
}
waylandFlush();
}
char* ShmBuffer::data() const { return _buffers[_current].data; }
wl_buffer* ShmBuffer::buffer() const { return _buffers[_current].buffer; }
void ShmBuffer::flip() { _current = 1-_current; }