#include "fb.h"

#include <assert.h>
#include <sys/ioctl.h>
#include <sys/mman.h>

fb_info_t fb_init(int drm_fd, drmModeModeInfo mode)
{
	int err;

	struct drm_mode_create_dumb create = {
		.width = mode.hdisplay,
		.height = mode.vdisplay,
		.bpp = 32,
	};
	err = ioctl(drm_fd, DRM_IOCTL_MODE_CREATE_DUMB, &create);
	assert(err != -1);

	uint32_t id;
	err = drmModeAddFB(
	    drm_fd, create.width, create.height, 24, 32, create.pitch,
	    create.handle, &id);
	assert(err == 0);

	struct drm_mode_map_dumb map = { .handle = create.handle };
	err = ioctl(drm_fd, DRM_IOCTL_MODE_MAP_DUMB, &map);
	assert(err != -1);

	uint32_t *buf = mmap(
	    0, create.size, PROT_READ | PROT_WRITE, MAP_SHARED, drm_fd,
	    map.offset);
	assert(buf != MAP_FAILED);

	return (fb_info_t) {
		.buf = buf,
		.handle = create.handle,
		.id = id,
		.pitch = create.pitch,
		.size = create.size,
	};
}

void fb_cleanup(int drm_fd, fb_info_t fb)
{
	munmap(fb.buf, fb.size);
	drmModeRmFB(drm_fd, fb.id);
	struct drm_mode_destroy_dumb delete = { .handle = fb.handle };
	ioctl(drm_fd, DRM_IOCTL_MODE_DESTROY_DUMB, &delete);
}