139 lines
3.0 KiB
C
139 lines
3.0 KiB
C
#define _POSIX_C_SOURCE 200809L
|
|
|
|
#include <assert.h>
|
|
#include <fcntl.h>
|
|
#include <stdint.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <sys/ioctl.h>
|
|
#include <sys/mman.h>
|
|
#include <sys/select.h>
|
|
#include <unistd.h>
|
|
#include <xf86drm.h>
|
|
#include <xf86drmMode.h>
|
|
|
|
typedef struct {
|
|
uint32_t *buf;
|
|
uint32_t handle;
|
|
uint32_t id;
|
|
uint32_t pitch;
|
|
uint32_t size;
|
|
} fb_info_t;
|
|
|
|
fb_info_t fb_init(int fd, drmModeModeInfo mode)
|
|
{
|
|
int err;
|
|
|
|
struct drm_mode_create_dumb create = {
|
|
.width = mode.hdisplay,
|
|
.height = mode.vdisplay,
|
|
.bpp = 32,
|
|
};
|
|
err = ioctl(fd, DRM_IOCTL_MODE_CREATE_DUMB, &create);
|
|
assert(err != -1);
|
|
|
|
uint32_t id;
|
|
err = drmModeAddFB(
|
|
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(fd, DRM_IOCTL_MODE_MAP_DUMB, &map);
|
|
assert(err != -1);
|
|
|
|
uint32_t *buf = mmap(
|
|
0, create.size, PROT_READ | PROT_WRITE, MAP_SHARED, 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 fd, fb_info_t fb)
|
|
{
|
|
munmap(fb.buf, fb.size);
|
|
drmModeRmFB(fd, fb.id);
|
|
struct drm_mode_destroy_dumb delete = { .handle = fb.handle };
|
|
ioctl(fd, DRM_IOCTL_MODE_DESTROY_DUMB, &delete);
|
|
}
|
|
|
|
static void page_flip_handler(int, unsigned, unsigned, unsigned, void *)
|
|
{
|
|
}
|
|
|
|
int main()
|
|
{
|
|
int err;
|
|
|
|
const int fd = open("/dev/dri/card1", O_RDWR | O_CLOEXEC);
|
|
assert(fd != -1);
|
|
|
|
drmModeRes *res = drmModeGetResources(fd);
|
|
assert(res != nullptr);
|
|
drmModeConnector *conn = drmModeGetConnector(fd, res->connectors[0]);
|
|
assert(conn != nullptr);
|
|
drmModeModeInfo mode = conn->modes[0];
|
|
uint32_t conn_id = conn->connector_id;
|
|
|
|
fb_info_t fbs[2] = {
|
|
fb_init(fd, mode),
|
|
fb_init(fd, mode),
|
|
};
|
|
int front = 0, back = 1;
|
|
|
|
err = drmModeSetCrtc(
|
|
fd, res->crtcs[0], fbs[front].id, 0, 0, &conn_id, 1, &mode);
|
|
assert(err == 0);
|
|
drmModeCrtc *crtc = drmModeGetCrtc(fd, res->crtcs[0]);
|
|
assert(crtc != nullptr);
|
|
|
|
fd_set set;
|
|
FD_ZERO(&set);
|
|
FD_SET(fd, &set);
|
|
|
|
drmEventContext ev = {
|
|
.version = DRM_EVENT_CONTEXT_VERSION,
|
|
.page_flip_handler = page_flip_handler,
|
|
};
|
|
|
|
for (uint64_t frame = 0; frame < (10 * 60); ++frame) {
|
|
for (int y = 0; y < mode.vdisplay; ++y) {
|
|
for (int x = 0; x < mode.hdisplay; ++x) {
|
|
const uint8_t r = (x + frame) % 256;
|
|
const uint8_t g = (y + frame) & 256;
|
|
const uint8_t b = (x + y + frame) % 256;
|
|
fbs[back].buf[y * (fbs[back].pitch / 4) + x]
|
|
= (r << 16) | (g << 8) | b;
|
|
}
|
|
}
|
|
|
|
drmModePageFlip(
|
|
fd, crtc->crtc_id, fbs[back].id, DRM_MODE_PAGE_FLIP_EVENT,
|
|
nullptr);
|
|
select(fd + 1, &set, nullptr, nullptr, nullptr);
|
|
drmHandleEvent(fd, &ev);
|
|
|
|
front = (front + 1) & 1;
|
|
back = (back + 1) & 1;
|
|
}
|
|
|
|
drmModeSetCrtc(
|
|
fd, crtc->crtc_id, crtc->buffer_id, crtc->x, crtc->y, &conn_id, 1,
|
|
&crtc->mode);
|
|
|
|
fb_cleanup(fd, fbs[0]);
|
|
fb_cleanup(fd, fbs[1]);
|
|
drmModeFreeCrtc(crtc);
|
|
drmModeFreeConnector(conn);
|
|
drmModeFreeResources(res);
|
|
close(fd);
|
|
|
|
return 0;
|
|
}
|