From 5f87ae3918d3bdffd2663487141d2f1d992bc4c6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lukas=20H=C3=B6ppner?= <lukas.hoeppner@gmail.com>
Date: Wed, 12 Aug 2026 23:27:16 +0200
Subject: [PATCH] ppuClear call from zig to c# simulator; not yet implemented
 in simulator; also breakpoints are not working in vs-code

---
 core/src/nova64_api.c        | 166 +++++++++++++++++++++++++++-
 simulator/Program.cs         |  10 +-
 simulator/sd/slot0/init.wasm | Bin 169 -> 242 bytes
 software/init.zig            |   4 +-
 software/nova64.zig          | 202 ++++++++++++++++++++++++++++++++++-
 5 files changed, 374 insertions(+), 8 deletions(-)

diff --git a/core/src/nova64_api.c b/core/src/nova64_api.c
index e3643a0..cb5c313 100644
--- a/core/src/nova64_api.c
+++ b/core/src/nova64_api.c
@@ -1,10 +1,14 @@
 #include "FreeRTOS.h"
+#include "nova64_framebuffer.h"
 #include "nova64_internal.h"
 #include "projdefs.h"
 #include "task.h"
 #include "wasm_export.h"
 #include <string.h>
 
+/* ========================================================================== */
+/* Core Native Callbacks                                                      */
+/* ========================================================================== */
 
 static void native_yield(wasm_exec_env_t exec_env, uint32_t timeout_ms) {
   if (timeout_ms == 0) {
@@ -28,10 +32,170 @@ static void native_log(wasm_exec_env_t exec_env, const char *message) {
   }
 }
 
+/* ========================================================================== */
+/* PPU Native Callbacks                                                       */
+/* ========================================================================== */
+
+static void native_ppu_fill_rect(wasm_exec_env_t exec_env, int32_t x, int32_t y,
+                                 int32_t w, int32_t h, uint32_t color) {
+  (void)exec_env;
+  const nova64_ppu_interface_t *ppu = nova64_get_ppu_interface();
+  if (ppu && ppu->fill_rect) {
+    ppu->fill_rect(nova64_framebuffer.back_buffer, NOVA64_DISPLAY_WIDTH, x, y,
+                   w, h, (pixel_t)color);
+  }
+}
+
+static void native_ppu_clear(wasm_exec_env_t exec_env, uint32_t color) {
+  (void)exec_env;
+  nova64_framebuffer_clear((pixel_t)color);
+}
+
+static void native_ppu_blit(wasm_exec_env_t exec_env, uint32_t src_wasm_ptr,
+                            uint32_t src_stride, int32_t src_x, int32_t src_y,
+                            int32_t dst_x, int32_t dst_y, int32_t w,
+                            int32_t h) {
+  wasm_module_inst_t module_inst = wasm_runtime_get_module_inst(exec_env);
+  const pixel_t *src_native = (const pixel_t *)wasm_runtime_addr_app_to_native(
+      module_inst, src_wasm_ptr);
+
+  if (!src_native)
+    return;
+
+  const nova64_ppu_interface_t *ppu = nova64_get_ppu_interface();
+  if (ppu && ppu->blit) {
+    ppu->blit(src_native, src_stride, nova64_framebuffer.back_buffer,
+              NOVA64_DISPLAY_WIDTH, src_x, src_y, dst_x, dst_y, w, h);
+  }
+}
+
+static void native_ppu_blit_colorkey(wasm_exec_env_t exec_env,
+                                     uint32_t src_wasm_ptr, uint32_t src_stride,
+                                     int32_t src_x, int32_t src_y,
+                                     int32_t dst_x, int32_t dst_y, int32_t w,
+                                     int32_t h, uint32_t key_color) {
+  wasm_module_inst_t module_inst = wasm_runtime_get_module_inst(exec_env);
+  const pixel_t *src_native = (const pixel_t *)wasm_runtime_addr_app_to_native(
+      module_inst, src_wasm_ptr);
+
+  if (!src_native)
+    return;
+
+  const nova64_ppu_interface_t *ppu = nova64_get_ppu_interface();
+  if (ppu && ppu->blit_colorkey) {
+    ppu->blit_colorkey(src_native, src_stride, nova64_framebuffer.back_buffer,
+                       NOVA64_DISPLAY_WIDTH, src_x, src_y, dst_x, dst_y, w, h,
+                       (pixel_t)key_color);
+  }
+}
+
+static void native_ppu_blend(wasm_exec_env_t exec_env, uint32_t src_wasm_ptr,
+                             uint32_t src_stride, int32_t src_x, int32_t src_y,
+                             int32_t dst_x, int32_t dst_y, int32_t w, int32_t h,
+                             uint32_t global_alpha) {
+  wasm_module_inst_t module_inst = wasm_runtime_get_module_inst(exec_env);
+  const pixel_t *src_native = (const pixel_t *)wasm_runtime_addr_app_to_native(
+      module_inst, src_wasm_ptr);
+
+  if (!src_native)
+    return;
+
+  const nova64_ppu_interface_t *ppu = nova64_get_ppu_interface();
+  if (ppu && ppu->blend) {
+    ppu->blend(src_native, src_stride, nova64_framebuffer.back_buffer,
+               NOVA64_DISPLAY_WIDTH, src_x, src_y, dst_x, dst_y, w, h,
+               (uint8_t)global_alpha);
+  }
+}
+
+static void native_ppu_blit_transform(wasm_exec_env_t exec_env,
+                                      uint32_t src_wasm_ptr,
+                                      uint32_t src_stride, int32_t src_x,
+                                      int32_t src_y, int32_t dst_x,
+                                      int32_t dst_y, int32_t w, int32_t h,
+                                      uint32_t transform) {
+  wasm_module_inst_t module_inst = wasm_runtime_get_module_inst(exec_env);
+  const pixel_t *src_native = (const pixel_t *)wasm_runtime_addr_app_to_native(
+      module_inst, src_wasm_ptr);
+
+  if (!src_native)
+    return;
+
+  const nova64_ppu_interface_t *ppu = nova64_get_ppu_interface();
+  if (ppu && ppu->blit_transform) {
+    ppu->blit_transform(src_native, src_stride, nova64_framebuffer.back_buffer,
+                        NOVA64_DISPLAY_WIDTH, src_x, src_y, dst_x, dst_y, w, h,
+                        (nova64_transform_t)transform);
+  }
+}
+
+static void native_ppu_blit_scale(wasm_exec_env_t exec_env,
+                                  uint32_t src_wasm_ptr, uint32_t src_stride,
+                                  int32_t src_w, int32_t src_h, int32_t dst_x,
+                                  int32_t dst_y, int32_t dst_w, int32_t dst_h) {
+  wasm_module_inst_t module_inst = wasm_runtime_get_module_inst(exec_env);
+  const pixel_t *src_native = (const pixel_t *)wasm_runtime_addr_app_to_native(
+      module_inst, src_wasm_ptr);
+
+  if (!src_native)
+    return;
+
+  const nova64_ppu_interface_t *ppu = nova64_get_ppu_interface();
+  if (ppu && ppu->blit_scale) {
+    ppu->blit_scale(src_native, src_stride, src_w, src_h,
+                    nova64_framebuffer.back_buffer, NOVA64_DISPLAY_WIDTH, dst_x,
+                    dst_y, dst_w, dst_h);
+  }
+}
+
+static void native_ppu_wait_idle(wasm_exec_env_t exec_env) {
+  (void)exec_env;
+  const nova64_ppu_interface_t *ppu = nova64_get_ppu_interface();
+  if (ppu && ppu->wait_idle) {
+    ppu->wait_idle();
+  }
+}
+
+static uint32_t native_ppu_is_busy(wasm_exec_env_t exec_env) {
+  (void)exec_env;
+  const nova64_ppu_interface_t *ppu = nova64_get_ppu_interface();
+  if (ppu && ppu->is_busy) {
+    return ppu->is_busy() ? 1 : 0;
+  }
+  return 0;
+}
+
+static void native_framebuffer_swap(wasm_exec_env_t exec_env) {
+  (void)exec_env;
+  nova64_framebuffer_swap();
+}
+
+/* ========================================================================== */
+/* WAMR Native Symbols Table                                                 */
+/* ========================================================================== */
+
 static NativeSymbol native_symbols[] = {
     {"nova64_yield", (void *)native_yield, "(i)", NULL},
     {"nova64_log", (void *)native_log, "($)", NULL},
-    // { "flush_framebuffer",  (void*)native_flush_framebuffer, "()",  NULL }
+
+    // Framebuffer Controls
+    {"nova64_ppu_clear", (void *)native_ppu_clear, "(i)", NULL},
+    {"nova64_framebuffer_swap", (void *)native_framebuffer_swap, "()", NULL},
+
+    // PPU Drawing Primitives
+    {"nova64_ppu_fill_rect", (void *)native_ppu_fill_rect, "(iiiii)", NULL},
+    {"nova64_ppu_blit", (void *)native_ppu_blit, "(iiiiiiiii)", NULL},
+    {"nova64_ppu_blit_colorkey", (void *)native_ppu_blit_colorkey,
+     "(iiiiiiiiii)", NULL},
+    {"nova64_ppu_blend", (void *)native_ppu_blend, "(iiiiiiiiii)", NULL},
+    {"nova64_ppu_blit_transform", (void *)native_ppu_blit_transform,
+     "(iiiiiiiiii)", NULL},
+    {"nova64_ppu_blit_scale", (void *)native_ppu_blit_scale, "(iiiiiiiii)",
+     NULL},
+
+    // Hardware Sync
+    {"nova64_ppu_wait_idle", (void *)native_ppu_wait_idle, "()", NULL},
+    {"nova64_ppu_is_busy", (void *)native_ppu_is_busy, "()i", NULL},
 };
 
 void nova64_register_imports(void) {
diff --git a/simulator/Program.cs b/simulator/Program.cs
index 716af5d..c810880 100644
--- a/simulator/Program.cs
+++ b/simulator/Program.cs
@@ -13,7 +13,6 @@ internal static class Program
         return SdRoot / $"slot{slotIdx}" / normalizedPath;
     }
 
-    private static readonly Nova64.DisplayFlushDelegate DisplayFlush = (buffer, width, height) => { };
     private static readonly Nova64.AudioOutputDelegate AudioOutput = (samples, count) => { };
     private static readonly Nova64.SdReadFileDelegate SdReadFile = (slotIdx, filePath, destinationBuffer, destinationLength) =>
     {
@@ -47,6 +46,7 @@ internal static class Program
             return -1;
         }
     };
+
     private static readonly Nova64.SdGetFileSizeDelegate SdGetFileSize = (slotIdx, filePath) =>
     {
         var path = GetSlotFilePath(slotIdx, filePath);
@@ -69,6 +69,7 @@ internal static class Program
             return -1;
         }
     };
+
     private static readonly Nova64.CartridgeStatusDelegate CartridgeStatus = (slotIdx, isInserted) => { };
     private static readonly Nova64.LogMessageDelegate LogMessage = (message) =>
     {
@@ -76,6 +77,11 @@ internal static class Program
         Console.Out.Flush();
     };
 
+    private static readonly Nova64.PpuFillRectDelegate FillRect = (dst, dstStride, x, y, w, h, color) =>
+    {
+        
+    };
+
     private static GCHandle? _ioHandle;
     private static GCHandle? _ppuHandle;
     private static Thread? _coreThread;
@@ -129,7 +135,7 @@ internal static class Program
 
             var ppuInterface = new Nova64.Nova64PpuInterface
             {
-
+                fill_rect = Marshal.GetFunctionPointerForDelegate(FillRect),
             };
 
             _ppuHandle = GCHandle.Alloc(ppuInterface, GCHandleType.Pinned);
diff --git a/simulator/sd/slot0/init.wasm b/simulator/sd/slot0/init.wasm
index f70185274749ffd0ce74997ce7be6e3a30fe0aa7..fca6774f7745c580e8300fccda4409ffa4ada9dd 100644
GIT binary patch
delta 150
zcmZ3<_=z!vA+b1@k%57Mk%K9Lv7RA;fq^NFg)J|?EYZw_3qr-`<fk(*K*a>0Vg&`I
z@yR)<iA8W3ai~mMQDSatQfXRRYEgV~d13(r<3vqYH5M*yMok802ginn0}TuU4M4!)
T$RN-Nq6M13JOP2`iEYXNH^eK7

delta 77
zcmeywxROzmA+b1@k%57Mk%K9Lv7RA;fq_Yzi7hX`EYZw_3qr-`<fk(*OiXc=VB(Tx
blxARdaBOHe(7+(j00az<Mgol!&np7}srVCO

diff --git a/software/init.zig b/software/init.zig
index 9a3e489..faeaac9 100644
--- a/software/init.zig
+++ b/software/init.zig
@@ -5,7 +5,9 @@ pub fn main() void {
     while (true) {
         nova64.log("Hello from Zig!");
         // nova64.yield();
-        nova64.sleep(50);
+        nova64.ppuClear(0x00);
+        nova64.ppuSwapBuffers();
+        nova64.sleep(16);
     }
 }
 
diff --git a/software/nova64.zig b/software/nova64.zig
index 6ad6ea2..5ee4974 100644
--- a/software/nova64.zig
+++ b/software/nova64.zig
@@ -1,8 +1,104 @@
-pub extern "nova64" fn nova64_yield(timeout_ms: u32) void;
-pub extern "nova64" fn nova64_log(message: [*]const u8) void;
+const std = @import("std");
 
-pub fn log(message: []const u8) void {
-    nova64_log(message.ptr);
+// ============================================================================
+// Types & Enums
+// ============================================================================
+
+/// RGB565 Color Format (16-bit)
+pub const Color = u16;
+
+/// Transformation flags for hardware-accelerated sprite operations.
+pub const Transform = packed struct(u32) {
+    flip_h: bool = false,
+    flip_v: bool = false,
+    rot_90: bool = false,
+    rot_180: bool = false,
+    rot_270: bool = false,
+    _padding: u27 = 0,
+};
+
+// Common Transform Constants
+pub const TRANSFORM_NONE = Transform{};
+pub const TRANSFORM_FLIP_H = Transform{ .flip_h = true };
+pub const TRANSFORM_FLIP_V = Transform{ .flip_v = true };
+
+// ============================================================================
+// Low-Level C-Imports (Raw WAMR Native Symbol Bindings)
+// ============================================================================
+
+pub extern "nova64" fn nova64_yield(timeout_ms: u32) void;
+pub extern "nova64" fn nova64_log(message: [*:0]const u8) void;
+
+// Framebuffer Controls
+pub extern "nova64" fn nova64_ppu_clear(color: u32) void;
+pub extern "nova64" fn nova64_framebuffer_swap() void;
+
+// PPU Drawing Primitives
+pub extern "nova64" fn nova64_ppu_fill_rect(x: i32, y: i32, w: i32, h: i32, color: u32) void;
+pub extern "nova64" fn nova64_ppu_blit(
+    src_ptr: [*]const Color,
+    src_stride: u32,
+    src_x: i32,
+    src_y: i32,
+    dst_x: i32,
+    dst_y: i32,
+    w: i32,
+    h: i32,
+) void;
+pub extern "nova64" fn nova64_ppu_blit_colorkey(
+    src_ptr: [*]const Color,
+    src_stride: u32,
+    src_x: i32,
+    src_y: i32,
+    dst_x: i32,
+    dst_y: i32,
+    w: i32,
+    h: i32,
+    key_color: u32,
+) void;
+pub extern "nova64" fn nova64_ppu_blend(
+    src_ptr: [*]const Color,
+    src_stride: u32,
+    src_x: i32,
+    src_y: i32,
+    dst_x: i32,
+    dst_y: i32,
+    w: i32,
+    h: i32,
+    global_alpha: u32,
+) void;
+pub extern "nova64" fn nova64_ppu_blit_transform(
+    src_ptr: [*]const Color,
+    src_stride: u32,
+    src_x: i32,
+    src_y: i32,
+    dst_x: i32,
+    dst_y: i32,
+    w: i32,
+    h: i32,
+    transform: Transform,
+) void;
+pub extern "nova64" fn nova64_ppu_blit_scale(
+    src_ptr: [*]const Color,
+    src_stride: u32,
+    src_w: i32,
+    src_h: i32,
+    dst_x: i32,
+    dst_y: i32,
+    dst_w: i32,
+    dst_h: i32,
+) void;
+
+// Hardware Sync
+pub extern "nova64" fn nova64_ppu_wait_idle() void;
+pub extern "nova64" fn nova64_ppu_is_busy() u32;
+
+// ============================================================================
+// High-Level Idiomatic Zig API
+// ============================================================================
+
+pub fn log(message: [*:0]const u8) void {
+    nova64_log(message);
 }
 
 pub fn sleep(timeout_ms: u32) void {
@@ -12,3 +108,101 @@ pub fn sleep(timeout_ms: u32) void {
 pub fn yield() void {
     nova64_yield(0);
 }
+
+/// Swaps the front and back buffer to display the rendered frame.
+pub fn ppuSwapBuffers() void {
+    nova64_framebuffer_swap();
+}
+
+/// Clears the back buffer with a solid RGB565 color.
+pub fn ppuClear(color: Color) void {
+    nova64_ppu_clear(@as(u32, color));
+}
+
+/// Fills a rectangle on the back buffer with a solid RGB565 color.
+pub fn ppuFillRect(x: i32, y: i32, w: i32, h: i32, color: Color) void {
+    nova64_ppu_fill_rect(x, y, w, h, @as(u32, color));
+}
+
+/// Opaque block image transfer from a pixel buffer to the back buffer.
+pub fn ppuBlit(
+    src: []const Color,
+    src_stride: u32,
+    src_x: i32,
+    src_y: i32,
+    dst_x: i32,
+    dst_y: i32,
+    w: i32,
+    h: i32,
+) void {
+    nova64_ppu_blit(src.ptr, src_stride, src_x, src_y, dst_x, dst_y, w, h);
+}
+
+/// Transparent sprite blitting using color keying.
+pub fn ppuBlitColorKey(
+    src: []const Color,
+    src_stride: u32,
+    src_x: i32,
+    src_y: i32,
+    dst_x: i32,
+    dst_y: i32,
+    w: i32,
+    h: i32,
+    key_color: Color,
+) void {
+    nova64_ppu_blit_colorkey(src.ptr, src_stride, src_x, src_y, dst_x, dst_y, w, h, @as(u32, key_color));
+}
+
+/// Alpha-blended sprite composition (alpha: 0 = transparent, 255 = opaque).
+pub fn ppuBlend(
+    src: []const Color,
+    src_stride: u32,
+    src_x: i32,
+    src_y: i32,
+    dst_x: i32,
+    dst_y: i32,
+    w: i32,
+    h: i32,
+    alpha: u8,
+) void {
+    nova64_ppu_blend(src.ptr, src_stride, src_x, src_y, dst_x, dst_y, w, h, @as(u32, alpha));
+}
+
+/// Transformed image transfer (rotation & flipping).
+pub fn ppuBlitTransform(
+    src: []const Color,
+    src_stride: u32,
+    src_x: i32,
+    src_y: i32,
+    dst_x: i32,
+    dst_y: i32,
+    w: i32,
+    h: i32,
+    transform: Transform,
+) void {
+    nova64_ppu_blit_transform(src.ptr, src_stride, src_x, src_y, dst_x, dst_y, w, h, transform);
+}
+
+/// Hardware-accelerated image scaling/resizing.
+pub fn ppuBlitScale(
+    src: []const Color,
+    src_stride: u32,
+    src_w: i32,
+    src_h: i32,
+    dst_x: i32,
+    dst_y: i32,
+    dst_w: i32,
+    dst_h: i32,
+) void {
+    nova64_ppu_blit_scale(src.ptr, src_stride, src_w, src_h, dst_x, dst_y, dst_w, dst_h);
+}
+
+/// Blocks execution until the PPU/DMA2D hardware engine finishes all operations.
+pub fn ppuWaitIdle() void {
+    nova64_ppu_wait_idle();
+}
+
+/// Checks if the PPU hardware engine is currently busy.
+pub fn ppuIsBusy() bool {
+    return nova64_ppu_is_busy() != 0;
+}