terminal renderer (truecolor half-block), input, screenshot mode

1 files changed, 61 insertions, 3 deletions

diff --git a/src/main.c b/src/main.c
index 27e886a..273d6b7 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,8 +1,28 @@
 #include "gb.h"
 #include "cpu.h"
+#include "render.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <time.h>
+#include <signal.h>
+
+static volatile sig_atomic_t running = 1;
+static void on_sig(int s) { (void)s; running = 0; }
+
+static double now_sec(void) {
+    struct timespec ts;
+    clock_gettime(CLOCK_MONOTONIC, &ts);
+    return ts.tv_sec + ts.tv_nsec / 1e9;
+}
+
+static void run_frame(GB *gb) {
+    gb->ppu.frame_ready = false;
+    // safety bound in case LCD is off (no frame_ready)
+    u64 budget = gb->cycles + 70224 * 2;
+    while (!gb->ppu.frame_ready && gb->cycles < budget)
+        cpu_step(gb);
+}
 
 int main(int argc, char **argv) {
     if (argc < 2) {
@@ -12,15 +32,20 @@ int main(int argc, char **argv) {
     const char *rom = argv[1];
     bool test = false;
     double seconds = 30.0;
+    int shot_frames = -1;
+    const char *shot_path = "shot.ppm";
     for (int i = 2; i < argc; i++) {
         if (!strcmp(argv[i], "--test")) {
             test = true;
             if (i + 1 < argc) seconds = atof(argv[++i]);
+        } else if (!strcmp(argv[i], "--shot")) {
+            if (i + 1 < argc) shot_frames = atoi(argv[++i]);
+            if (i + 1 < argc && argv[i+1][0] != '-') shot_path = argv[++i];
         }
     }
 
     GB *gb = calloc(1, sizeof(GB));
-    if (cart_load(&gb->cart, rom) != 0) return 1;
+    if (cart_load(&gb->cart, rom) != 0) { free(gb); return 1; }
     gb_reset(gb);
 
     if (test) {
@@ -33,8 +58,41 @@ int main(int argc, char **argv) {
         return 0;
     }
 
-    // TODO: interactive terminal rendering
-    fprintf(stderr, "interactive mode not yet implemented; use --test\n");
+    if (shot_frames >= 0) {
+        for (int f = 0; f < shot_frames; f++) run_frame(gb);
+        FILE *pf = fopen(shot_path, "wb");
+        fprintf(pf, "P6\n%d %d\n255\n", SCREEN_W, SCREEN_H);
+        for (int y = 0; y < SCREEN_H; y++)
+            for (int x = 0; x < SCREEN_W; x++)
+                fwrite(gb->ppu.fb[y][x], 1, 3, pf);
+        fclose(pf);
+        fprintf(stderr, "wrote %s after %d frames\n", shot_path, shot_frames);
+        cart_free(&gb->cart); free(gb); return 0;
+    }
+
+    signal(SIGINT, on_sig);
+    signal(SIGTERM, on_sig);
+    term_init();
+
+    const double frame_time = 1.0 / 59.73;
+    double next = now_sec();
+    while (running) {
+        if (!input_poll(gb)) break;
+        run_frame(gb);
+        render_frame(gb);
+
+        next += frame_time;
+        double t = now_sec();
+        double sleep = next - t;
+        if (sleep > 0) {
+            struct timespec ts = { (time_t)sleep, (long)((sleep - (time_t)sleep) * 1e9) };
+            nanosleep(&ts, NULL);
+        } else if (sleep < -0.1) {
+            next = t; // fell behind; resync
+        }
+    }
+
+    term_restore();
     cart_free(&gb->cart);
     free(gb);
     return 0;