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authorJune McEnroe <june@causal.agency>2018-02-09 15:14:33 -0500
committerJune McEnroe <june@causal.agency>2018-02-09 15:14:33 -0500
commit68dab38c2c8b000a0918f6427d6d53261a6ce5bb (patch)
tree0abcfc5fa42d3e79a90acf5e1ead79f1e06ed3fa /bin/gfx/fb.c
parentAdd janky X11 graphics frontend (diff)
downloadsrc-68dab38c2c8b000a0918f6427d6d53261a6ce5bb.tar.gz
src-68dab38c2c8b000a0918f6427d6d53261a6ce5bb.zip
Move gfx frontends around to simplify build
I forgot that you can expand variables inside variables names in make.
Certainly makes some fun things possible.
Diffstat (limited to 'bin/gfx/fb.c')
-rw-r--r--bin/gfx/fb.c90
1 files changed, 90 insertions, 0 deletions
diff --git a/bin/gfx/fb.c b/bin/gfx/fb.c
new file mode 100644
index 00000000..bc4d9d46
--- /dev/null
+++ b/bin/gfx/fb.c
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+/* 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 <err.h>
+#include <fcntl.h>
+#include <linux/fb.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sysexits.h>
+#include <termios.h>
+#include <unistd.h>
+
+extern int init(int argc, char *argv[]);
+extern const char *status(void);
+extern void draw(uint32_t *buf, size_t xres, size_t yres);
+extern bool input(char in);
+
+static struct termios saveTerm;
+static void restoreTerm(void) {
+    tcsetattr(STDERR_FILENO, TCSADRAIN, &saveTerm);
+}
+
+int main(int argc, char *argv[]) {
+    int error;
+
+    error = init(argc, argv);
+    if (error) return error;
+
+    const char *path = getenv("FRAMEBUFFER");
+    if (!path) path = "/dev/fb0";
+
+    int fb = open(path, O_RDWR);
+    if (fb < 0) err(EX_OSFILE, "%s", path);
+
+    struct fb_var_screeninfo info;
+    error = ioctl(fb, FBIOGET_VSCREENINFO, &info);
+    if (error) err(EX_IOERR, "%s", path);
+
+    size_t size = 4 * info.xres * info.yres;
+    uint32_t *buf = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fb, 0);
+    if (buf == MAP_FAILED) err(EX_IOERR, "%s", path);
+
+    error = tcgetattr(STDERR_FILENO, &saveTerm);
+    if (error) err(EX_IOERR, "tcgetattr");
+    atexit(restoreTerm);
+
+    struct termios term = saveTerm;
+    term.c_lflag &= ~(ICANON | ECHO);
+    error = tcsetattr(STDERR_FILENO, TCSADRAIN, &term);
+    if (error) err(EX_IOERR, "tcsetattr");
+
+    uint32_t saveBg = buf[0];
+
+    uint32_t back[info.xres * info.yres];
+    for (;;) {
+        draw(back, info.xres, info.yres);
+        memcpy(buf, back, size);
+
+        char in;
+        ssize_t len = read(STDERR_FILENO, &in, 1);
+        if (len < 0) err(EX_IOERR, "read");
+        if (!len) return EX_DATAERR;
+
+        if (!input(in)) {
+            for (uint32_t i = 0; i < info.xres * info.yres; ++i) {
+                buf[i] = saveBg;
+            }
+            fprintf(stderr, "%s\n", status());
+            return EX_OK;
+        }
+    }
+}