Display maps from OCaml

src/core/cbindings.ml

@@ -2,3 +2,4 @@ let () =
   Callback.register "oboy_name" Version.name;
   Callback.register "oboy_version" Version.version;
   Callback.register "oboy_load" State.load_cartridge;
+  Callback.register "oboy_bg_map" Memory.background_map;

src/core/dune

@@ -3,6 +3,7 @@
 ; combine static pthread with dynamic libc
 (executable
 	(name cbindings)
+	(libraries bigarray)
 	(modes object))
 
 ; Standalone binary

src/core/memory.ml

@@ -6,6 +6,7 @@
  * LICENSE file at the top level directory of this source tree.
  *)
 
+open Bigarray
 open Bytes
 open Printf
 
@@ -107,3 +108,13 @@ let update_timers mem cycles =
       (* TODO: INT 50 - Timer interupt *)
     end
   end
+
+let background_map () =
+  let bg_map = Array2.create Bigarray.int8_unsigned Bigarray.c_layout 8 8 in
+  Array2.fill bg_map 0;
+  for j = 0 to (Array2.dim2 bg_map) - 1 do
+    for i = 0 to (Array2.dim1 bg_map) - 1 do
+      bg_map.{i, j} <- (i + j * Array2.dim1 bg_map) mod 4
+    done
+  done;
+  bg_map

src/qt/BackgroundMap.qml

@@ -12,8 +12,14 @@ Window {
     maximumHeight: height
     minimumHeight: height
 
-    BackgroundMapForm {
+//    BackgroundMapForm {
-        anchors.fill: parent
+//        anchors.fill: parent
-    }
+//    }
 
+    Image {
+        source: "image://oboy/bg_map"
+        anchors.fill: parent
+        smooth: false
+        fillMode: Image.PreserveAspectFit
+    }
 }

src/qt/CMakeLists.txt

@@ -10,7 +10,7 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 find_package(Qt5 COMPONENTS Core Quick REQUIRED)
 
-add_executable(${PROJECT_NAME} "main.cpp" "oboy.cpp" "qml.qrc")
+add_executable(${PROJECT_NAME} "main.cpp" "oboy.cpp" "oimageprovider.cpp" "qml.qrc")
 target_compile_definitions(${PROJECT_NAME} PRIVATE $<$<OR:$<CONFIG:Debug>,$<CONFIG:RelWithDebInfo>>:QT_QML_DEBUG>)
 target_link_libraries(${PROJECT_NAME} PRIVATE Qt5::Core Qt5::Quick)
 

src/qt/main.cpp

@@ -3,10 +3,10 @@
 #include <iostream>
 #include <string>
 
-#include <caml/mlvalues.h>
-#include <caml/callback.h>
-
 #include "oboy.h"
+#include "oimageprovider.h"
+
+#include <caml/callback.h>
 
 int main(int argc, char *argv[])
 {
@@ -16,6 +16,7 @@ int main(int argc, char *argv[])
     qmlRegisterType<OBoy>("com.oboy.oboy", 1, 0, "OBoy");
 
     QQmlApplicationEngine engine;
+    engine.addImageProvider(QLatin1String("oboy"), new OImageProvider(engine));
     engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
 
     caml_main(argv);

src/qt/main.qml

@@ -27,6 +27,7 @@ ApplicationWindow {
             title: qsTr("View")
             MenuItem {
                 text: qsTr("Background maps")
+                enabled: oboy.loaded
                 onTriggered: {
                     console.log("Background maps");
                     var component = Qt.createComponent("BackgroundMap.qml")
@@ -52,6 +53,7 @@ ApplicationWindow {
 
     OBoy {
         id: oboy
+        objectName: "qml_oboy"
     }
 
     MainForm {

src/qt/oboy.cpp

@@ -1,15 +1,26 @@
 #include "oboy.h"
 
+#include <QtGlobal>
+
 #include <caml/mlvalues.h>
 #include <caml/callback.h>
 #include <caml/alloc.h>
+#include <caml/bigarray.h>
 #include <caml/memory.h>
 #include <caml/misc.h>
 #include <caml/osdeps.h>
 
 OBoy::OBoy(QObject *parent) : QObject(parent)
 {
+//    load("/Users/ffreling/Downloads/Super_Mario_Land.gb");
+}
 
+value *fetch_caml_callback(const char *name) {
+    value * closure_f = caml_named_value(name);
+    if (closure_f == nullptr) {
+        qFatal("Cannot find OCaml function: %s", name);
+    }
+    return closure_f;
 }
 
 // https://caml.inria.fr/pub/docs/manual-ocaml/intfc.html
@@ -19,7 +30,7 @@ QString OBoy::name() const
 {
     CAMLparam0();
 
-    value * closure_f = caml_named_value("oboy_name");
+    static value * closure_f = fetch_caml_callback("oboy_name");
     if (closure_f == nullptr) {
         CAMLdrop;
         return QString("<Unreachable>");
@@ -34,7 +45,7 @@ QString OBoy::version() const
 {
     CAMLparam0();
 
-    value * closure_f = caml_named_value("oboy_version");
+    static value * closure_f = fetch_caml_callback("oboy_version");
     if (closure_f == nullptr) {
         CAMLdrop;
         return QString("<Unreachable>");
@@ -50,7 +61,7 @@ bool OBoy::load(const QString &path)
     CAMLparam0();
     CAMLlocal1(ocaml_path) ;
 
-    value * closure_f = caml_named_value("oboy_load");
+    static value * closure_f = fetch_caml_callback("oboy_load");
     if (closure_f == nullptr) {
         CAMLdrop;
         return false;
@@ -72,3 +83,41 @@ bool OBoy::loaded() const
 {
     return _loaded;
 }
+
+QImage OBoy::backgroundMap() const
+{
+    CAMLparam0();
+
+    static value * closure_f = fetch_caml_callback("oboy_bg_map");
+    if (closure_f == nullptr) {
+        CAMLdrop;
+        return QImage(0, 0, QImage::Format_Indexed8);
+    }
+
+    const auto bg_array = Caml_ba_array_val(caml_callback(*closure_f, Val_unit));
+    const auto bg_raw_data = static_cast<caml_ba_uint8 *>(bg_array->data);
+
+    Q_ASSERT(bg_array->num_dims == 2);
+    Q_ASSERT(bg_array->flags & CAML_BA_UINT8);
+
+    const int width = bg_array->dim[0];
+    const int height = bg_array->dim[1];
+    QImage img(width, height, QImage::Format_Indexed8);
+
+    QVector<QRgb> green_palette = {
+        qRgb(15, 56, 15),
+        qRgb(48, 98, 48),
+        qRgb(139, 172, 15),
+        qRgb(155, 188, 15),
+    };
+    img.setColorTable(green_palette);
+
+    for (int y = 0; y < height; ++y) {
+        for (int x = 0; x < width; ++x) {
+            img.setPixel(x, y, bg_raw_data[y * width + x] % 4);
+        }
+    }
+
+    CAMLdrop;
+    return img;
+}

src/qt/oboy.h

@@ -1,6 +1,8 @@
 #pragma once
 
 #include <QObject>
+#include <QImage>
+#include <QString>
 
 class OBoy : public QObject
 {
@@ -8,6 +10,7 @@ class OBoy : public QObject
     Q_PROPERTY(QString name READ name CONSTANT)
     Q_PROPERTY(QString version READ version CONSTANT)
     Q_PROPERTY(bool loaded READ loaded NOTIFY loadedChanged)
+    Q_PROPERTY(QImage backgroundMap READ backgroundMap CONSTANT)
 public:
     explicit OBoy(QObject *parent = nullptr);
 
@@ -15,6 +18,7 @@ public:
     QString version() const;
     bool loaded() const;
     Q_INVOKABLE bool load(const QString &path);
+    QImage backgroundMap() const;
 
 signals:
     void loadedChanged(bool loaded);

src/qt/oimageprovider.cpp

@@ -0,0 +1,22 @@
+#include "oimageprovider.h"
+#include "oboy.h"
+
+OImageProvider::OImageProvider(QQmlApplicationEngine &engine)
+    : QQuickImageProvider(QQuickImageProvider::Image)
+    , _engine(engine)
+{
+
+}
+
+QImage OImageProvider::requestImage(const QString &id, QSize *size, const QSize &requestedSize)
+{
+    QList<QObject*> roots = _engine.rootObjects();
+    OBoy *oboy = roots[0]->findChild<OBoy*>("qml_oboy");
+    if (!oboy) {
+        qFatal("Cannot find oboy instance.");
+    }
+    Q_ASSERT(oboy->loaded());
+
+    QImage img = oboy->backgroundMap();
+    return img;
+}

src/qt/oimageprovider.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include <QQmlApplicationEngine>
+#include <QQuickImageProvider>
+
+class OImageProvider : public QQuickImageProvider
+{
+public:
+    OImageProvider(QQmlApplicationEngine &engine);
+    QImage requestImage(const QString &id, QSize *size, const QSize &requestedSize) override;
+
+private:
+    QQmlApplicationEngine &_engine;
+};