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-rw-r--r--bin/gfxx.c264
1 files changed, 264 insertions, 0 deletions
diff --git a/bin/gfxx.c b/bin/gfxx.c
new file mode 100644
index 00000000..e5bf93da
--- /dev/null
+++ b/bin/gfxx.c
@@ -0,0 +1,264 @@
+#include <err.h>
+#include <fcntl.h>
+#include <linux/fb.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sysexits.h>
+#include <termios.h>
+#include <unistd.h>
+
+struct Buffer {
+    uint32_t *data;
+    size_t xres;
+    size_t yres;
+};
+
+static int init(int argc, char *argv[]);
+static void draw(struct Buffer buf);
+static void 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;
+    struct Buffer buf = {
+        .data = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fb, 0),
+        .xres = info.xres,
+        .yres = info.yres,
+    };
+    if (buf.data == 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");
+
+    for (;;) {
+        draw(buf);
+
+        char in;
+        ssize_t len = read(STDERR_FILENO, &in, 1);
+        if (len < 0) err(EX_IOERR, "read");
+        if (!len) return EX_DATAERR;
+
+        input(in);
+    }
+}
+
+// ABSTRACTION LINE
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+
+static uint8_t bits = 1;
+static bool endian;
+static bool reverse;
+static size_t width = 16;
+static size_t offset;
+static size_t scale = 1;
+
+static size_t size = 1024 * 1024;
+static uint8_t *data;
+
+static uint8_t get(size_t i) {
+    if (reverse) {
+        return data[size - i - 1];
+    } else {
+        return data[i];
+    }
+}
+
+static int init(int argc, char *argv[]) {
+    const char *path = NULL;
+
+    int opt;
+    while (0 < (opt = getopt(argc, argv, "b:en:rw:z:"))) {
+        switch (opt) {
+            case 'b': bits     = strtoul(optarg, NULL, 0); break;
+            case 'e': endian  ^= true; break;
+            case 'n': offset   = strtoul(optarg, NULL, 0); break;
+            case 'r': reverse ^= true; break;
+            case 'w': width    = strtoul(optarg, NULL, 0); break;
+            case 'z': scale    = strtoul(optarg, NULL, 0); break;
+            default: return EX_USAGE;
+        }
+    }
+    if (argc > optind) path = argv[optind];
+    if (!bits || !width || !scale) return EX_USAGE;
+
+    FILE *file = path ? fopen(path, "r") : stdin;
+    if (!file) err(EX_NOINPUT, "%s", path);
+
+    if (path) {
+        struct stat stat;
+        int error = fstat(fileno(file), &stat);
+        if (error) err(EX_IOERR, "%s", path);
+        size = stat.st_size;
+    }
+
+    data = malloc(size);
+    if (!data) err(EX_OSERR, "malloc(%zu)", size);
+
+    size = fread(data, 1, size, file);
+    if (ferror(file)) err(EX_IOERR, "%s", path);
+
+    return EX_OK;
+}
+
+static void dump(void) {
+    printf(
+        "gfxx %s%s-b %hhu -n %zu -w %zu -z %zu\n",
+        reverse ? "-r " : "",
+        endian ? "-e " : "",
+        bits,
+        offset,
+        width,
+        scale
+    );
+}
+
+struct Cursor {
+    size_t left;
+    size_t x;
+    size_t y;
+};
+
+static struct Cursor step(struct Buffer buf, struct Cursor cur) {
+    cur.x++;
+    if (cur.x - cur.left == width) {
+        cur.y++;
+        cur.x = cur.left;
+    }
+    if (cur.y == buf.yres / scale) {
+        cur.left += width;
+        cur.x = cur.left;
+        cur.y = 0;
+    }
+    return cur;
+}
+
+static void put(struct Buffer buf, struct Cursor cur, uint32_t p) {
+    size_t scaledX = cur.x * scale;
+    size_t scaledY = cur.y * scale;
+    for (size_t fillY = scaledY; fillY < scaledY + scale; ++fillY) {
+        if (fillY >= buf.yres) break;
+        for (size_t fillX = scaledX; fillX < scaledX + scale; ++fillX) {
+            if (fillX >= buf.xres) break;
+            buf.data[fillY * buf.xres + fillX] = p;
+        }
+    }
+}
+
+// TODO: Palette.
+static void draw1(struct Buffer buf) {
+    struct Cursor cur = {0};
+    for (size_t i = offset; i < size; ++i) {
+        for (int s = 0; s < 8; ++s) {
+            uint8_t b = get(i) >> (endian ? s : 7 - s) & 1;
+            uint32_t p = b ? 0xFFFFFF : 0x000000;
+            put(buf, cur, p);
+            cur = step(buf, cur);
+        }
+    }
+}
+
+// TODO: Palette.
+static void draw8(struct Buffer buf) {
+    struct Cursor cur = {0};
+    for (size_t i = offset; i < size; ++i) {
+        uint32_t p = get(i) | get(i) << 8 | get(i) << 16;
+        put(buf, cur, p);
+        cur = step(buf, cur);
+    }
+}
+
+static void draw24(struct Buffer buf) {
+    struct Cursor cur = {0};
+    for (size_t i = offset; i + 2 < size; i += 3) {
+        uint32_t p = (endian)
+            ? get(i) << 16 | get(i+1) <<  8 | get(i+2) <<  0
+            : get(i) <<  0 | get(i+1) <<  8 | get(i+2) << 16;
+        put(buf, cur, p);
+        cur = step(buf, cur);
+    }
+}
+
+static void draw32(struct Buffer buf) {
+    struct Cursor cur = {0};
+    for (size_t i = offset; i + 3 < size; i += 4) {
+        uint32_t p = (endian)
+            ? get(i) << 24 | get(i+1) << 16 | get(i+2) <<  8 | get(i+3) <<  0
+            : get(i) <<  0 | get(i+1) <<  8 | get(i+2) << 16 | get(i+3) << 24;
+        put(buf, cur, p);
+        cur = step(buf, cur);
+    }
+}
+
+static void draw(struct Buffer buf) {
+    memset(buf.data, 0, 4 * buf.xres * buf.yres);
+    switch (bits) {
+        case 1:  draw1(buf);  break;
+        case 8:  draw8(buf);  break;
+        case 24: draw24(buf); break;
+        case 32: draw32(buf); break;
+        default: break;
+    }
+}
+
+static void input(char in) {
+    switch (in) {
+        case 'q': dump(); exit(EX_OK);
+        break; case '+': scale++;
+        break; case '-': if (scale > 1) scale--;
+        break; case '.': width++;
+        break; case ',': if (width > 1) width--;
+        break; case '>': width *= 2;
+        break; case '<': if (width / 2 >= 1) width /= 2;
+        break; case 'h': if (offset) offset--;
+        break; case 'j': offset += width;
+        break; case 'k': if (offset >= width) offset -= width;
+        break; case 'l': offset++;
+        break; case 'e': endian ^= true;
+        break; case 'r': reverse ^= true;
+        break; case 'b':
+            switch (bits) {
+                case 1:  bits =  8; break;
+                case 32: bits =  1; break;
+                default: bits += 8;
+            }
+        break; case 'B':
+            switch (bits) {
+                case 1:  bits = 32; break;
+                case 8:  bits =  1; break;
+                default: bits -= 8;
+            }
+    }
+}