brightstone/Player/Display/x11.c

#include <X11/X.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <assert.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

#include "../../Common/lzw.h"
#include "../../Common/mat.h"
#include "display.h"

bool quited = false;

#define WIDTH 640
#define HEIGHT 480

// TODO: correct error handling.
extern int plr_display_x11_main(int argc, char *argv[]) {
  char test_string[] = "what is this?";
  char *compressed_string = NULL;
  uint32_t compressed_string_sz = 0;
  struct com_lzw_table table =
      com_lzw_infer_table(test_string, sizeof(test_string));
  bool test = com_lzw_compress(&table, test_string, sizeof(test_string),
                               &compressed_string, &compressed_string_sz);
  com_lzw_free_table(&table);
  assert(test);

  com_mat_t m0 = com_mat_identity();
  com_mat_t m1 = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16};
  for (int i = 0; i < 16; ++i)
    m1.a[i] *= COM_FIXED_FRACUNIT;

  com_mat_t t0 = com_mat_mul(m1, m0);
  com_mat_t t1 = com_mat_mul_reodered(com_mat_reoder(m1), m0);
  com_fixed_print(t0.a[4]);
  com_fixed_print(t1.a[4]);

  com_vec_t v0 = com_mat_vec_project(com_mat_reoder(m0), com_vec_identity());
  com_fixed_print(v0.a[0]);

  com_fixed_run_tests();

  Display *display = XOpenDisplay(NULL);
  if (NULL == display) {
    fprintf(stderr, "Failed to initialize display");
    return EXIT_FAILURE;
  }

  Window root = DefaultRootWindow(display);
  if (None == root) {
    fprintf(stderr, "No root window found");
    XCloseDisplay(display);
    return EXIT_FAILURE;
  }

  int screen = DefaultScreen(display);
  Visual *visual = DefaultVisual(display, screen);
  int depth = DefaultDepth(display, screen);

  Window window =
      XCreateSimpleWindow(display, root, 0, 0, WIDTH, HEIGHT, 0, 0, 0xffffffff);
  if (None == window) {
    fprintf(stderr, "Failed to create window");
    XCloseDisplay(display);
    return EXIT_FAILURE;
  }

  XSizeHints *hints = XAllocSizeHints();
  if (hints == NULL)
    return EXIT_FAILURE;

  // Pinning min and max to the same values disables resizing
  hints->flags = PMinSize | PMaxSize;
  hints->min_width = hints->max_width = WIDTH;
  hints->min_height = hints->max_height = HEIGHT;

  XSetWMNormalHints(display, window, hints);
  XFree(hints);

  XSelectInput(display, window, ExposureMask | KeyPressMask);
  XMapWindow(display, window);

  GC gc = XCreateGC(display, window, 0, NULL);

  Atom wm_delete_window = XInternAtom(display, "WM_DELETE_WINDOW", False);
  XSetWMProtocols(display, window, &wm_delete_window, 1);

  // TODO: can't be not true
  int bytes_per_pixel = 4;
  char *pixel_buffer = (char *)malloc(WIDTH * HEIGHT * bytes_per_pixel);

  XImage *ximage = XCreateImage(display, visual, depth, ZPixmap, 0,
                                pixel_buffer, WIDTH, HEIGHT, 32, 0);

  if (!ximage) {
    fprintf(stderr, "Failed to create XImage\n");
    free(pixel_buffer);
    XCloseDisplay(display);
    return EXIT_FAILURE;
  }

  int frame = 0;

  XEvent event;
  while (!quited) {
    XNextEvent(display, &event);

    switch (event.type) {
    case ClientMessage:
      if (event.xclient.data.l[0] == wm_delete_window) {
        XDestroyWindow(display, window);
        quited = true;
      }
      break;

    case Expose:
      frame += 2;
      // Fill buffer with a simple color gradient
      for (int y = 0; y < HEIGHT; y++) {
        for (int x = 0; x < WIDTH; x++) {
          int pixel_index = (y * WIDTH + x) * bytes_per_pixel;

          // Assuming standard Little-Endian 32-bit BGRA format
          pixel_buffer[pixel_index + 0] = (x + frame) % 256;     // Blue
          pixel_buffer[pixel_index + 1] = (y + frame) % 256;     // Green
          pixel_buffer[pixel_index + 2] = (x + y - frame) % 256; // Red
          pixel_buffer[pixel_index + 3] = 0; // Alpha/Padding
        }
      }
      // Draw the complete image onto the window when exposed
      XPutImage(display,
                window,       // Target drawable
                gc,           // Graphics Context
                ximage,       // Source XImage
                0, 0,         // Source coordinates (x, y)
                0, 0,         // Destination coordinates (x, y)
                WIDTH, HEIGHT // Dimensions to copy
      );
      break;
    }
  }

  XCloseDisplay(display);

  return 0;
}