/** * \file * [: description :] * * \author * Georg Hopp <georg@steffers.org> * * \copyright * Copyright © 2019 Georg Hopp * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ // http://stackoverflow.com/questions/27745131 #include <sys/ipc.h> #include <sys/shm.h> #include <xcb/xcb.h> #include <xcb/xcb_image.h> #include <xcb/shm.h> #include <stdio.h> #define W 512 #define H 512 int main(){ //connect to the X server and get screen xcb_connection_t* connection = xcb_connect(NULL, NULL); xcb_screen_t* screen = xcb_setup_roots_iterator(xcb_get_setup(connection)).data; //create a window uint32_t value_mask = XCB_CW_BACK_PIXEL|XCB_CW_EVENT_MASK; uint32_t value_list[2] = {screen->black_pixel, XCB_EVENT_MASK_EXPOSURE}; xcb_window_t window = xcb_generate_id(connection); xcb_create_window(connection, screen->root_depth, window, screen->root, 0, 0, W, H, 0, XCB_WINDOW_CLASS_INPUT_OUTPUT, screen->root_visual, value_mask, value_list); //create a graphic context value_mask = XCB_GC_FOREGROUND|XCB_GC_GRAPHICS_EXPOSURES; value_list[0] = screen->black_pixel; value_list[1] = 0; xcb_gcontext_t gcontext = xcb_generate_id(connection); xcb_create_gc(connection, gcontext, window, value_mask, value_list); //map the window onto the screen xcb_map_window(connection, window); xcb_flush(connection); //Shm test xcb_shm_segment_info_t info; xcb_shm_query_version_reply(connection, xcb_shm_query_version(connection), NULL); info.shmid = shmget(IPC_PRIVATE, W*H*4, IPC_CREAT|0777); info.shmaddr = shmat(info.shmid, 0, 0); info.shmseg = xcb_generate_id(connection); xcb_shm_attach(connection, info.shmseg, info.shmid, 0); shmctl(info.shmid, IPC_RMID, 0); uint8_t* data = info.shmaddr; xcb_pixmap_t pix = xcb_generate_id(connection); xcb_shm_create_pixmap(connection, pix, window, W, H, screen->root_depth, info.shmseg, 0); uint8_t lala[W*H*4] = {0}; const xcb_setup_t* setup = xcb_get_setup(connection); xcb_format_t* fmt = xcb_setup_pixmap_formats(setup); printf("scanline_pad %u depth %u bpp %u byte_order %u\n", fmt->scanline_pad, fmt->depth, fmt->bits_per_pixel, setup->image_byte_order); xcb_image_t* img = xcb_image_create(W,H, XCB_IMAGE_FORMAT_Z_PIXMAP, fmt->scanline_pad, 24, 32, 0, setup->image_byte_order, XCB_IMAGE_ORDER_LSB_FIRST, lala, W*H*4, lala); // xcb_image_shm_get(connection, window, img, info, 0,0, XCB_IMAGE_FORMAT_Z_PIXMAP); // xcb_image_shm_put(connection, window, img, info, 0,0, XCB_IMAGE_FORMAT_Z_PIXMAP); // -------------------------------------------------------------- uint i = 0; while(1){ data[i++] = 0xff; xcb_copy_area(connection, pix, window, gcontext, 0, 0, 0, 0, W, H); xcb_flush(connection); } xcb_shm_detach(connection, info.shmseg); shmdt(info.shmaddr); xcb_free_pixmap(connection, pix); xcb_destroy_window(connection, window); xcb_disconnect(connection); } // vim: set ts=4 sw=4: