Add janky X11 graphics frontend

1 files changed, 124 insertions, 0 deletions

diff --git a/bin/gfx11.c b/bin/gfx11.c
new file mode 100644
index 00000000..53d84895
--- /dev/null
+++ b/bin/gfx11.c
@@ -0,0 +1,124 @@
+/* Copyright (c) 2018, June McEnroe <programble@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <X11/Xlib.h>
+#include <err.h>
+#include <sysexits.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+extern int init(int argc, char *argv[]);
+extern const char *status(void);
+extern void draw(uint32_t *buf, size_t width, size_t height);
+extern bool input(char in);
+
+static size_t width;
+static size_t height;
+
+static size_t bufSize;
+static uint32_t *buf;
+
+static Display *display;
+static Window window;
+static GC gc;
+static XImage *image;
+static Pixmap pixmap;
+
+static void resize(size_t newWidth, size_t newHeight) {
+    size_t newSize = 4 * newWidth * newHeight;
+    if (newSize > bufSize) {
+        free(buf);
+        buf = malloc(newSize);
+        if (!buf) err(EX_OSERR, "malloc(%zu)", newSize);
+        bufSize = newSize;
+    }
+
+    image->data = (char *)buf;
+    image->width = newWidth;
+    image->height = newHeight;
+    image->bytes_per_line = 4 * newWidth;
+
+    if (pixmap) XFreePixmap(display, pixmap);
+    pixmap = XCreatePixmap(display, window, newWidth, newHeight, 24);
+
+    width = newWidth;
+    height = newHeight;
+}
+
+static void drawWindow(void) {
+    draw(buf, width, height);
+    XPutImage(display, pixmap, gc, image, 0, 0, 0, 0, width, height);
+    XCopyArea(display, pixmap, window, gc, 0, 0, width, height, 0, 0);
+}
+
+int main(int argc, char *argv[]) {
+    int error = init(argc, argv);
+    if (error) return error;
+
+    display = XOpenDisplay(NULL);
+    if (!display) errx(EX_UNAVAILABLE, "XOpenDisplay: %s", XDisplayName(NULL));
+
+    Window root = DefaultRootWindow(display);
+    window = XCreateSimpleWindow(display, root, 0, 0, 800, 600, 0, 0, 0);
+    gc = XCreateGC(display, window, 0, NULL);
+    image = XCreateImage(display, NULL, 24, ZPixmap, 0, NULL, 0, 0, 32, 0);
+
+    Atom WM_DELETE_WINDOW = XInternAtom(display, "WM_DELETE_WINDOW", false);
+    XSetWMProtocols(display, window, &WM_DELETE_WINDOW, 1);
+
+    XStoreName(display, window, status());
+    XMapWindow(display, window);
+
+    XEvent event;
+    XSelectInput(display, window, ExposureMask | StructureNotifyMask | KeyPressMask);
+    for (;;) {
+        XNextEvent(display, &event);
+        switch (event.type) {
+            case KeyPress: {
+                XKeyEvent key = event.xkey;
+                KeySym sym = XLookupKeysym(&key, key.state);
+                if (sym > 128) break;
+                if (!input(sym)) return EX_OK;
+                drawWindow();
+            } break;
+
+            case ConfigureNotify: {
+                XConfigureEvent configure = event.xconfigure;
+                resize(configure.width, configure.height);
+                drawWindow();
+            } break;
+
+            case Expose: {
+                XExposeEvent expose = event.xexpose;
+                XCopyArea(
+                    display,
+                    pixmap, window, gc,
+                    expose.x, expose.y,
+                    expose.width, expose.height,
+                    expose.x, expose.y
+                );
+            } break;
+
+            case ClientMessage: {
+                XClientMessageEvent message = event.xclient;
+                if ((Atom)message.data.l[0] == WM_DELETE_WINDOW) {
+                    return EX_OK;
+                }
+            } break;
+        }
+    }
+}