Sync updates at 60hz

2 files changed, 85 insertions, 70 deletions

diff --git a/Makefile b/Makefile
index 8de6bb0..3d41a4a 100644
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,7 @@ EXE_NAME  ?= uxnfb
 BIN       := $(BUILD_DIR)/$(EXE_NAME)
 UXN_HEAD  := $(BASE_UXN)/src/uxn.h
 TAL_SRC   ?= $(BASE_UXN)/projects/examples/devices/screen.tal
-UXN_ROM   ?= $(BUILD_DIR)/screen.rom
+UXN_ROM   ?= $(BUILD_DIR)/rom.rom
 UXN_ASM   ?= $(BUILD_DIR)/uxnasm
 
 CC        ?= cc
diff --git a/src/main.c b/src/main.c
index 1a4d6f6..e213bbb 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,9 +1,11 @@
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <stdint.h>
-#include <stdbool.h>
+#include <time.h>
 #include <unistd.h>
-#include <fcntl.h>
+
 #include <linux/fb.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
@@ -18,6 +20,21 @@ static Device *devctrl;
 static Device *devmouse;
 static Device *devaudio;
 
+typedef struct timespec Time;
+
+Time
+time_now(){
+    struct timespec t;
+    clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &t);
+    return t;
+}
+
+size_t
+time_elapsed(Time since){
+    struct timespec now = time_now();
+    return (now.tv_sec - since.tv_sec) * 1e9 + (now.tv_nsec - since.tv_nsec);
+}
+
 void
 nil_talk(Device *d, u8 b0, u8 w) {
     (void)d;
@@ -36,11 +53,11 @@ console_talk(Device *d, u8 b0, u8 w) {
     // }
     // switch(b0) {
     //     case 0x8: stmp[0] = d->dat[0x8]; stmp[1] = 0; uart_puts(stmp); break;
-        // TODO: implement printf for the uart to be able to format
-        // numbers.
-        // case 0x9: txt_printf("0x%02x", d->dat[0x9]); break;
-        // case 0xb: txt_printf("0x%04x", mempeek16(d->dat, 0xa)); break;
-        // case 0xd: txt_printf("%s", &d->mem[mempeek16(d->dat, 0xc)]); break;
+    // TODO: implement printf for the uart to be able to format
+    // numbers.
+    // case 0x9: txt_printf("0x%02x", d->dat[0x9]); break;
+    // case 0xb: txt_printf("0x%04x", mempeek16(d->dat, 0xa)); break;
+    // case 0xd: txt_printf("%s", &d->mem[mempeek16(d->dat, 0xc)]); break;
     // }
 }
 
@@ -70,14 +87,14 @@ void
 system_talk(Device *d, u8 b0, u8 w) {
     if(!w) { /* read */
         switch(b0) {
-        case 0x2: d->dat[0x2] = d->u->wst.ptr; break;
-        case 0x3: d->dat[0x3] = d->u->rst.ptr; break;
+            case 0x2: d->dat[0x2] = d->u->wst.ptr; break;
+            case 0x3: d->dat[0x3] = d->u->rst.ptr; break;
         }
     } else { /* write */
         switch(b0) {
-        case 0x2: d->u->wst.ptr = d->dat[0x2]; break;
-        case 0x3: d->u->rst.ptr = d->dat[0x3]; break;
-        case 0xf: d->u->ram.ptr = 0x0000; break;
+            case 0x2: d->u->wst.ptr = d->dat[0x2]; break;
+            case 0x3: d->u->rst.ptr = d->dat[0x3]; break;
+            case 0xf: d->u->ram.ptr = 0x0000; break;
         }
         if(b0 > 0x7 && b0 < 0xe) {
             docolors(d);
@@ -91,51 +108,51 @@ screen_talk(Device *d, u8 b0, u8 w) {
     if (w) {
         switch (b0) {
             case 0x1: {
-                d->vector = mempeek16(d->dat, 0x0);
-            } break;
+                          d->vector = mempeek16(d->dat, 0x0);
+                      } break;
             case 0xe: {
-                u16 x = mempeek16(d->dat, 0x8);
-                u16 y = mempeek16(d->dat, 0xa);
-                u8 *addr = &d->mem[mempeek16(d->dat, 0xc)];
-                u8 *layer = d->dat[0xe] >> 4 & 0x1 ? pixels_fg : pixels_bg;
-                u8 mode = d->dat[0xe] >> 5;
-                u8 color = d->dat[0xf] & 0xf;
-                if(!mode) {
-                    ppu_pixel(layer, x, y, d->dat[0xe] & 0x3);
-                } else if(mode-- & 0x1) {
-                    u8 flipx = mode & 0x2;
-                    u8 flipy = mode & 0x4;
-                    ppu_1bpp(layer, x, y, addr, color, flipx, flipy);
-                } else {
-                    u8 flipx = mode & 0x2;
-                    u8 flipy = mode & 0x4;
-                    ppu_2bpp(layer, x, y, addr, color, flipx, flipy);
-                }
-                if(d->dat[0x6] & 0x01) { mempoke16(d->dat, 0x8, x + 1); }
-                if(d->dat[0x6] & 0x02) { mempoke16(d->dat, 0xa, y + 1); }
-            } break;
+                          u16 x = mempeek16(d->dat, 0x8);
+                          u16 y = mempeek16(d->dat, 0xa);
+                          u8 *addr = &d->mem[mempeek16(d->dat, 0xc)];
+                          u8 *layer = d->dat[0xe] >> 4 & 0x1 ? pixels_fg : pixels_bg;
+                          u8 mode = d->dat[0xe] >> 5;
+                          u8 color = d->dat[0xf] & 0xf;
+                          if(!mode) {
+                              ppu_pixel(layer, x, y, d->dat[0xe] & 0x3);
+                          } else if(mode-- & 0x1) {
+                              u8 flipx = mode & 0x2;
+                              u8 flipy = mode & 0x4;
+                              ppu_1bpp(layer, x, y, addr, color, flipx, flipy);
+                          } else {
+                              u8 flipx = mode & 0x2;
+                              u8 flipy = mode & 0x4;
+                              ppu_2bpp(layer, x, y, addr, color, flipx, flipy);
+                          }
+                          if(d->dat[0x6] & 0x01) { mempoke16(d->dat, 0x8, x + 1); }
+                          if(d->dat[0x6] & 0x02) { mempoke16(d->dat, 0xa, y + 1); }
+                      } break;
             case 0xf: {
-                u16 x = mempeek16(d->dat, 0x8);
-                u16 y = mempeek16(d->dat, 0xa);
-                u8 *addr = &d->mem[mempeek16(d->dat, 0xc)];
-                u8 *layer = d->dat[0xf] >> 6 & 0x1 ? pixels_fg : pixels_bg;
-                u8 color = d->dat[0xf] & 0xf;
-                u8 flipx = (d->dat[0xf] >> 0x4) & 0x1;
-                u8 flipy = (d->dat[0xf] >> 0x5) & 0x1;
-                if(d->dat[0xf] >> 0x7 & 0x1) {
-                    ppu_2bpp(layer, x, y, addr, color, flipx, flipy);
-                    if(d->dat[0x6] & 0x04) {
-                        mempoke16(d->dat, 0xc, mempeek16(d->dat, 0xc) + 16);
-                    }
-                } else {
-                    ppu_1bpp(layer, x, y, addr, color, flipx, flipy);
-                    if(d->dat[0x6] & 0x04) {
-                        mempoke16(d->dat, 0xc, mempeek16(d->dat, 0xc) + 8);
-                    }
-                }
-                if(d->dat[0x6] & 0x01) { mempoke16(d->dat, 0x8, x + 8); }
-                if(d->dat[0x6] & 0x02) { mempoke16(d->dat, 0xa, y + 8); }
-            } break;
+                          u16 x = mempeek16(d->dat, 0x8);
+                          u16 y = mempeek16(d->dat, 0xa);
+                          u8 *addr = &d->mem[mempeek16(d->dat, 0xc)];
+                          u8 *layer = d->dat[0xf] >> 6 & 0x1 ? pixels_fg : pixels_bg;
+                          u8 color = d->dat[0xf] & 0xf;
+                          u8 flipx = (d->dat[0xf] >> 0x4) & 0x1;
+                          u8 flipy = (d->dat[0xf] >> 0x5) & 0x1;
+                          if(d->dat[0xf] >> 0x7 & 0x1) {
+                              ppu_2bpp(layer, x, y, addr, color, flipx, flipy);
+                              if(d->dat[0x6] & 0x04) {
+                                  mempoke16(d->dat, 0xc, mempeek16(d->dat, 0xc) + 16);
+                              }
+                          } else {
+                              ppu_1bpp(layer, x, y, addr, color, flipx, flipy);
+                              if(d->dat[0x6] & 0x04) {
+                                  mempoke16(d->dat, 0xc, mempeek16(d->dat, 0xc) + 8);
+                              }
+                          }
+                          if(d->dat[0x6] & 0x01) { mempoke16(d->dat, 0x8, x + 8); }
+                          if(d->dat[0x6] & 0x02) { mempoke16(d->dat, 0xa, y + 8); }
+                      } break;
             default: break;
         }
     }
@@ -226,22 +243,20 @@ main(int argc, char *argv[]) {
     }
     init_uxn(argv[1]);
 
-        // Main loop.
+    // Main loop.
     uxn_eval(&u, 0x0100);
-    // u64 current_ticks = timer_get_ticks();
+    Time frame_time = time_now();
     while (true) {
-        // Echo input to standard output.
-        uxn_eval(&u, mempeek16(devscreen->dat, 0));
-
-        // Blit ppu.pixels to the framebuffer.
-        blit_framebuffer();
+        size_t elapsed = time_elapsed(frame_time);
+        if (elapsed >= 16666666) {
+            // Echo input to standard output.
+            uxn_eval(&u, mempeek16(devscreen->dat, 0));
 
-        // TODO: Sync at 60 Hz.
-        // if ((timer_get_ticks() - current_ticks) < 16666) {
-        //     wait(16666 - (timer_get_ticks() - current_ticks));
-        // }
-        // current_ticks = timer_get_ticks();
+            // Blit ppu.pixels to the framebuffer.
+            blit_framebuffer();
+            frame_time = time_now();
+        }
     }
 
-        return 0;
+    return 0;
 }