diff --git a/main.c b/main.c index 7302cec..cf9f119 100644 --- a/main.c +++ b/main.c @@ -2,7 +2,9 @@ #include #include +#include #include +#include #include #include #include @@ -12,6 +14,8 @@ #include #include +#define MAX(a, b) ((a) < (b) ? (b) : (a)) + typedef struct { uint32_t *buf; uint32_t handle; @@ -20,7 +24,10 @@ typedef struct { uint32_t size; } fb_info_t; -fb_info_t fb_init(int fd, drmModeModeInfo mode) +static fb_info_t fbs[2]; +static int front = 0, back = 1; + +static fb_info_t fb_init(int drm_fd, drmModeModeInfo mode) { int err; @@ -29,21 +36,22 @@ fb_info_t fb_init(int fd, drmModeModeInfo mode) .height = mode.vdisplay, .bpp = 32, }; - err = ioctl(fd, DRM_IOCTL_MODE_CREATE_DUMB, &create); + err = ioctl(drm_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); + 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(fd, DRM_IOCTL_MODE_MAP_DUMB, &map); + 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, fd, map.offset); + 0, create.size, PROT_READ | PROT_WRITE, MAP_SHARED, drm_fd, + map.offset); assert(buf != MAP_FAILED); return (fb_info_t) { @@ -55,84 +63,110 @@ fb_info_t fb_init(int fd, drmModeModeInfo mode) }; } -void fb_cleanup(int fd, fb_info_t fb) +static void fb_cleanup(int drm_fd, fb_info_t fb) { munmap(fb.buf, fb.size); - drmModeRmFB(fd, fb.id); + drmModeRmFB(drm_fd, fb.id); struct drm_mode_destroy_dumb delete = { .handle = fb.handle }; - ioctl(fd, DRM_IOCTL_MODE_DESTROY_DUMB, &delete); + ioctl(drm_fd, DRM_IOCTL_MODE_DESTROY_DUMB, &delete); } static void page_flip_handler(int, unsigned, unsigned, unsigned, void *) { } +static void swap_buffers(int drm_fd, uint32_t crtc_id) +{ + const int err = drmModePageFlip( + drm_fd, crtc_id, fbs[back].id, DRM_MODE_PAGE_FLIP_EVENT, nullptr); + assert(err == 0); + + front = (front + 1) & 1; + back = (back + 1) & 1; +} + int main() { int err; - const int fd = open("/dev/dri/card1", O_RDWR | O_CLOEXEC); - assert(fd != -1); + const int input_fd = open("/dev/input/event0", O_RDONLY); + assert(input_fd != -1); - drmModeRes *res = drmModeGetResources(fd); + const int drm_fd = open("/dev/dri/card1", O_RDWR | O_CLOEXEC); + assert(drm_fd != -1); + + drmModeRes *res = drmModeGetResources(drm_fd); assert(res != nullptr); - drmModeConnector *conn = drmModeGetConnector(fd, res->connectors[0]); + drmModeConnector *conn = drmModeGetConnector(drm_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; + fbs[0] = fb_init(drm_fd, mode); + fbs[1] = fb_init(drm_fd, mode); err = drmModeSetCrtc( - fd, res->crtcs[0], fbs[front].id, 0, 0, &conn_id, 1, &mode); + drm_fd, res->crtcs[0], fbs[front].id, 0, 0, &conn_id, 1, &mode); assert(err == 0); - drmModeCrtc *crtc = drmModeGetCrtc(fd, res->crtcs[0]); + drmModeCrtc *crtc = drmModeGetCrtc(drm_fd, res->crtcs[0]); assert(crtc != nullptr); + memset(fbs[back].buf, 0, fbs[back].size); + swap_buffers(drm_fd, crtc->crtc_id); + + const int max_fd = MAX(input_fd, drm_fd); fd_set set; - FD_ZERO(&set); - FD_SET(fd, &set); + bool running = true; + uint64_t frame = 0; + while (running) { + FD_ZERO(&set); + FD_SET(input_fd, &set); + FD_SET(drm_fd, &set); + select(max_fd + 1, &set, nullptr, nullptr, nullptr); - drmEventContext ev = { - .version = DRM_EVENT_CONTEXT_VERSION, - .page_flip_handler = page_flip_handler, - }; + if (FD_ISSET(input_fd, &set)) { + struct input_event ev; + const int len = read(input_fd, &ev, sizeof(ev)); + assert(len == sizeof(ev)); - 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; + if (ev.type == EV_KEY && ev.value >= 0 && ev.value <= 2) { + if (ev.code == KEY_Q && ev.value == 1) + running = false; } } - drmModePageFlip( - fd, crtc->crtc_id, fbs[back].id, DRM_MODE_PAGE_FLIP_EVENT, - nullptr); - select(fd + 1, &set, nullptr, nullptr, nullptr); - drmHandleEvent(fd, &ev); + if (FD_ISSET(drm_fd, &set)) { + drmEventContext ev = { + .version = DRM_EVENT_CONTEXT_VERSION, + .page_flip_handler = page_flip_handler, + }; + drmHandleEvent(drm_fd, &ev); - front = (front + 1) & 1; - back = (back + 1) & 1; + 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; + } + } + + swap_buffers(drm_fd, crtc->crtc_id); + ++frame; + } } drmModeSetCrtc( - fd, crtc->crtc_id, crtc->buffer_id, crtc->x, crtc->y, &conn_id, 1, - &crtc->mode); + drm_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]); + fb_cleanup(drm_fd, fbs[0]); + fb_cleanup(drm_fd, fbs[1]); drmModeFreeCrtc(crtc); drmModeFreeConnector(conn); drmModeFreeResources(res); - close(fd); + close(drm_fd); return 0; }