Implement TImage drawing

gtk4/inc/TGtk4PadPainter.h

@@ -81,7 +81,9 @@ friend class TGtk4Canvas;
    void     DrawPolyMarker(Int_t n, const Double_t *x, const Double_t *y) override;
    void     DrawPolyMarker(Int_t n, const Float_t *x, const Float_t *y) override;
 
-   void   DrawTTFglyphs(Int_t x, Int_t y, TTFhandle &ttf, ETextMode mode) override;
+   void     DrawTTFglyphs(Int_t x, Int_t y, TTFhandle &ttf, ETextMode mode) override;
+
+   void     DrawImage(TImage *img, Int_t x, Int_t y, Int_t flags = 0) override;
 
    Bool_t   IsSupportAlpha() const override { return kTRUE; }
 

gtk4/src/TGtk4PadPainter.cxx

@@ -19,15 +19,16 @@
 #include "TROOT.h"
 #include "TColor.h"
 #include "RStipples.h"
-
 #include "TTFhandle.h"
+#include "TImage.h"
 
 #include <memory>
 #include <map>
 
 #include "Gtk4DrawArea.h"
 
 #include <cairomm/context.h>
+#include <cairomm/surface.h>
 #include <cairo.h>
 
 
@@ -553,3 +554,34 @@ void TGtk4PadPainter::DrawTTFglyphs(Int_t px, Int_t py, TTFhandle &ttf, ETextMod
       ctx->mask(surface, px + bx, py + by);
    }
 }
+
+
+////////////////////////////////////////////////////////////////////////////////
+/// Render TTF glyphs on drawable area
+
+void TGtk4PadPainter::DrawImage(TImage *img, Int_t px, Int_t py, Int_t)
+{
+   // position inside the pad is provided, therefore shift it to global image
+   px += fPad->UtoAbsPixel(0);
+   py += fPad->VtoAbsPixel(1);
+
+   auto width = img->GetWidth();
+   auto height = img->GetHeight();
+   auto argbBuffer = (unsigned char*) img->GetArgbArray();
+
+   auto ctx = fDrawArea->GetContext();
+
+   int stride = Cairo::ImageSurface::format_stride_for_width(Cairo::Surface::Format::ARGB32, width);
+
+    // 2. Wrap your raw memory pointer into a Cairo Surface.
+    // This borrows the memory pointer without making a deep copy.
+    Cairo::RefPtr<Cairo::ImageSurface> surface =
+        Cairo::ImageSurface::create(argbBuffer, Cairo::Surface::Format::ARGB32, width, height, stride);
+
+    // 3. Set the surface as the source pattern in the context
+    // (0, 0) specifies the top-left offset to place the image
+    ctx->set_source(surface, px, py);
+
+    // 4. Paint the pattern onto the context canvas
+    ctx->paint();
+}

qt6/inc/TQt6PadPainter.h

@@ -93,6 +93,8 @@ friend class TQt6Canvas;
 
    void     DrawTTFglyphs(Int_t px, Int_t py, TTFhandle &ttf, [[maybe_unused]] ETextMode mode) override;
 
+   void     DrawImage(TImage *img, Int_t x, Int_t y, Int_t flags = 0) override;
+
 private:
    //Let's make this clear:
    TQt6PadPainter(const TQt6PadPainter &rhs) = delete;

qt6/src/TQt6PadPainter.cxx

@@ -19,18 +19,16 @@
 #include "TROOT.h"
 #include "TColor.h"
 #include "RStipples.h"
+#include "TTFhandle.h"
+#include "TImage.h"
 
 #include <memory>
 #include <map>
 
 #include "QPaintWidget.h"
 
-#include "TTFhandle.h"
-
-
-#include <QFont>
-#include <QFontDatabase>
 #include <QRect>
+#include <QImage>
 #include <QPainter>
 
 using namespace ROOT::Experimental;
@@ -492,3 +490,33 @@ void TQt6PadPainter::DrawTTFglyphs(Int_t px, Int_t py, TTFhandle &ttf, [[maybe_u
    }
 }
 
+void TQt6PadPainter::DrawImage(TImage *img, Int_t px, Int_t py, Int_t)
+{
+   // position inside the pad is provided, therefore shift it to global image
+   px += fPad->UtoAbsPixel(0);
+   py += fPad->VtoAbsPixel(1);
+
+   auto width = img->GetWidth();
+   auto height = img->GetHeight();
+   auto argbBuffer = (const uchar*) img->GetArgbArray();
+
+   auto painter = fPaintWidget->getPainter();
+
+   int bytesPerLine = width * 4;
+
+    // 1. Wrap the raw memory array into a QImage.
+    // This constructor does NOT copy the pixel data; it points directly to your buffer.
+    QImage image(
+        argbBuffer,
+        width,
+        height,
+        bytesPerLine,
+        QImage::Format_ARGB32
+    );
+
+    // 2. Draw the image using QPainter
+    // (0, 0) is the top-left coordinate where the image will be drawn
+    painter->drawImage(px, py, image);
+}
+
+

raylib/inc/TRaylibPadPainter.h

@@ -97,6 +97,8 @@ friend class TRaylibCanvas;
 
    void DrawTTFglyphs(Int_t px, Int_t py, TTFhandle &ttf, [[maybe_unused]] ETextMode mode) override;
 
+   void DrawImage(TImage *img, Int_t x, Int_t y, Int_t flags = 0) override;
+
 private:
    TRaylibPadPainter(const TRaylibPadPainter &) = delete;
    TRaylibPadPainter(TRaylibPadPainter &&) = delete;

raylib/src/TRaylibPadPainter.cxx

@@ -19,9 +19,8 @@
 #include "TPoint.h"
 #include "TROOT.h"
 #include "TColor.h"
-
-#include "RStipples.h"
 #include "TTFhandle.h"
+#include "TImage.h"
 
 
 #include <raylib.h>
@@ -501,6 +500,57 @@ void TRaylibPadPainter::DrawTTFglyphs(Int_t px, Int_t py, TTFhandle &ttf, [[mayb
    }
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// Render image on drawable area
+
+void TRaylibPadPainter::DrawImage(TImage *img, Int_t px, Int_t py, Int_t)
+{
+   px += fPad->UtoAbsPixel(0);
+   py += fPad->VtoAbsPixel(1);
+
+   auto width = img->GetWidth();
+   auto height = img->GetHeight();
+   auto argbBuffer = (unsigned char*) img->GetArgbArray();
+
+   int pixelCount = width * height;
+
+   std::vector<unsigned char> rgbaData(pixelCount * 4);
+
+   // Convert ARGB/BGRA to RGBA in-memory
+   for (int i = 0; i < pixelCount; i++) {
+      int srcIdx = i * 4;
+      int dstIdx = i * 4;
+
+      // Assuming source is Cairo's Little-Endian BGRA format [B, G, R, A]:
+      rgbaData[dstIdx + 0] = argbBuffer[srcIdx + 2]; // Red
+      rgbaData[dstIdx + 1] = argbBuffer[srcIdx + 1]; // Green
+      rgbaData[dstIdx + 2] = argbBuffer[srcIdx + 0]; // Blue
+      rgbaData[dstIdx + 3] = argbBuffer[srcIdx + 3]; // Alpha
+   }
+
+   Image rayimg = {
+      .data = rgbaData.data(),
+      .width = (int)width,
+      .height = (int)height,
+      .mipmaps = 1,
+      .format =PIXELFORMAT_UNCOMPRESSED_R8G8B8A8
+   };
+
+   // Upload to GPU memory
+   Texture2D texture = LoadTextureFromImage(rayimg);
+
+   DrawTexture(texture, px, py, WHITE);
+
+   // Always unload transient textures to avoid GPU memory leaks!
+   // but we should wait until rendering is finished
+   fTextures.push_back(texture);
+}
+
+
+
+////////////////////////////////////////////////////////////////////////////////
+/// Cleanup context
+
 void TRaylibPadPainter::CleanupTextures()
 {
    for (auto &texture : fTextures)