1 files changed, 155 insertions, 0 deletions

diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..77cabcc
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,155 @@
+#include <string.h>
+
+#include "common.h"
+#include "bitmap.h"
+#include "text.h"
+#include "small-font.c"
+
+#include "uxn/uxn.h"
+#include "uxn/uxn.c"
+#include "uxn/devices/ppu.h"
+#include "uxn/devices/ppu.c"
+// #include "uxn/roms/console.c"
+#include "uxn/roms/dvd.c"
+// #include "uxn/roms/proportional_fonts.c"
+// #include "uxn/roms/automata.c"
+// #include "uxn/roms/life.c"
+
+static Ppu ppu;
+u8 reqdraw = 0;
+static Device *devscreen;
+
+void
+nil_talk(Device *d, Uint8 b0, Uint8 w) {
+        (void)d;
+        (void)b0;
+        (void)w;
+}
+
+void
+console_talk(Device *d, u8 b0, u8 w) {
+        if(!w) {
+        return;
+    }
+    switch(b0) {
+        case 0x8: txt_printf("%c", d->dat[0x8]); break;
+        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;
+    }
+}
+
+void
+system_talk(Device *d, Uint8 b0, Uint8 w)
+{
+        if(!w) {
+                d->dat[0x2] = d->u->wst.ptr;
+                d->dat[0x3] = d->u->rst.ptr;
+        } else {
+                putcolors(&ppu, &d->dat[0x8]);
+                reqdraw = 1;
+        }
+        (void)b0;
+}
+
+void
+screen_talk(Device *d, Uint8 b0, Uint8 w) {
+        if(w && b0 == 0xe) {
+                Uint16 x = mempeek16(d->dat, 0x8);
+                Uint16 y = mempeek16(d->dat, 0xa);
+                Uint8 *addr = &d->mem[mempeek16(d->dat, 0xc)];
+                Uint8 *layer = d->dat[0xe] >> 4 & 0x1 ? ppu.fg : ppu.bg;
+                Uint8 mode = d->dat[0xe] >> 5;
+                if(!mode) {
+                        putpixel(&ppu, layer, x, y, d->dat[0xe] & 0x3);
+                } else if(mode-- & 0x1) {
+                        puticn(&ppu, layer, x, y, addr, d->dat[0xe] & 0xf, mode & 0x2, mode & 0x4);
+        } else {
+                        putchr(&ppu, layer, x, y, addr, d->dat[0xe] & 0xf, mode & 0x2, mode & 0x4);
+        }
+                reqdraw = 1;
+        }
+}
+
+void
+redraw(Uint16 *dst, Uxn *u) {
+    // TODO: The screen will flicker but using Mode4 for double buffering would
+    // be way too slow.
+        drawppu(&ppu);
+    clear_screen_m3();
+    // Copy ppu data to framebuffer.
+    for (size_t j = 0; j < ppu.height; ++j) {
+        for (size_t i = 0; i < ppu.width; ++i) {
+            FRAMEBUFFER[j][i] = ppu.output[i + j * ppu.width];
+        }
+    }
+        reqdraw = 0;
+}
+
+void
+init_uxn(Uxn *u) {
+    // Initialize PPU.
+        initppu(&ppu, 30, 20, 0);
+
+        // Copy rom to VM.
+    memcpy(u->ram.dat + PAGE_PROGRAM, uxn_rom, sizeof(uxn_rom));
+
+    // Prepare devices.
+        portuxn(u, 0x0, "system", system_talk);
+        portuxn(u, 0x1, "console", console_talk);
+        devscreen = portuxn(u, 0x2, "screen", screen_talk);
+        portuxn(u, 0x3, "---", nil_talk);
+        portuxn(u, 0x4, "---", nil_talk);
+        portuxn(u, 0x5, "---", nil_talk);
+        portuxn(u, 0x6, "---", nil_talk);
+        portuxn(u, 0x7, "---", nil_talk);
+        portuxn(u, 0x8, "---", nil_talk);
+        portuxn(u, 0x9, "---", nil_talk);
+        portuxn(u, 0xa, "---", nil_talk);
+        portuxn(u, 0xb, "---", nil_talk);
+        portuxn(u, 0xc, "---", nil_talk);
+        portuxn(u, 0xd, "---", nil_talk);
+        portuxn(u, 0xe, "---", nil_talk);
+        portuxn(u, 0xf, "---", nil_talk);
+        mempoke16(devscreen->dat, 2, ppu.hor * 8);
+        mempoke16(devscreen->dat, 4, ppu.ver * 8);
+}
+
+int main(void) {
+    // Initialize display mode and bg palette.
+    DISP_CTRL = DISP_MODE_3 | DISP_BG_2;
+
+    // Initialize text engine.
+    txt_init_bitmap(
+            TXT_MODE_MODE3,
+            (Font){
+                .data = small_font,
+                .char_width = 4,
+                .char_height = 8,
+                .color = COLOR_BLUE,
+                .char_map = small_font_map,
+            });
+
+    // Register interrupts.
+    irq_init();
+    irs_set(IRQ_VBLANK, irs_stub);
+
+    // Initialize VM.
+    Uxn u = {0};
+    init_uxn(&u);
+        evaluxn(&u, 0x0100);
+
+    // Main loop.
+    int frame_counter = 0;
+    while(true) {
+        bios_vblank_wait();
+        poll_keys();
+                evaluxn(&u, mempeek16(devscreen->dat, 0));
+                if(reqdraw) {
+                        redraw(ppu.output, &u);
+        }
+        frame_counter++;
+    };
+
+    return 0;
+}