#include <errno.h>
#include <fcntl.h>
#include <gbm.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define RENDERNODE "/dev/dri/renderD128"

int main(int argc, char **argv) {
  int drm_fd = open(RENDERNODE, O_RDWR | O_CLOEXEC);
  if (drm_fd == -1) {
    fprintf(stderr, "Failed to open render node %s\n", RENDERNODE);
    return EXIT_FAILURE;
  }
  struct gbm_device *dev = gbm_create_device(drm_fd);
  if (!dev) {
    fprintf(stderr, "Failed to create gbm device\n");
    return EXIT_FAILURE;
  }

  uint32_t width = 256;
  uint32_t height = 512;
  uint32_t cpp = 4;
  uint32_t format = GBM_FORMAT_XRGB8888;
  struct gbm_bo *bo = gbm_bo_create(dev, width, height, format, 0);
  if (!bo) {
    fprintf(stderr, "Failed to create buffer object: %s\n", strerror(errno));
    return EXIT_FAILURE;
  }

  for (int i = 0; i < 8; i++) {
    uint32_t stride;
    void *handle = i != 4 ? NULL : 0x44;
    void *dst = gbm_bo_map(bo, 0, 0, width, height, GBM_BO_TRANSFER_WRITE,
                           &stride, &handle);
    if (!dst) {
      fprintf(stderr, "Failed to map gbm buffer the %dth time, error=%d: %s\n",
              i, errno, strerror(errno));
      return EXIT_FAILURE;
    }

    memset(dst, i, width * height * cpp);

    gbm_bo_unmap(bo, handle);
  }

  gbm_device_destroy(dev);
  close(drm_fd);

  fprintf(stderr, "Successful\n");
  return EXIT_SUCCESS;
}