GAL canvases: add DrawBitmap(), using a basic brute force algo for OpenGL, and a optimized code for Cairo. In this fix the brute force means draw each pixel as a rectangle. It works fine, but could be optimized.

(cherry picked from commit fefc7b8172)

common/gal/cairo/cairo_gal.cpp

@@ -33,6 +33,7 @@
 #include <gal/cairo/cairo_compositor.h>
 #include <gal/definitions.h>
 #include <geometry/shape_poly_set.h>
+#include <bitmap_base.h>
 
 #include <limits>
 
@@ -347,6 +348,61 @@ void CAIRO_GAL::DrawCurve( const VECTOR2D& aStartPoint, const VECTOR2D& aControl
 }
 
 
+void CAIRO_GAL::DrawBitmap( const BITMAP_BASE& aBitmap )
+{
+    int ppi = aBitmap.GetPPI();
+    double worldIU_per_mm = 1/(worldUnitLength/2.54)/1000;
+    double pix_size_iu =  worldIU_per_mm * ( 25.4 / ppi );
+    int w = aBitmap.GetSizePixels().x;
+    int h = aBitmap.GetSizePixels().y;
+
+    cairo_save( currentContext );
+
+    // Set the pixel scaling factor:
+    cairo_scale( currentContext, pix_size_iu, pix_size_iu );
+    // The position of the bitmap is the bitmap center.
+    // move the draw origin to the top left bitmap corner:
+    cairo_translate( currentContext, -w/2, -h/2 );
+
+    cairo_new_path( currentContext );
+    cairo_surface_t *image;
+    image = cairo_image_surface_create( CAIRO_FORMAT_RGB24, w, h );
+    cairo_surface_flush( image );
+
+    unsigned char* pix_buffer = cairo_image_surface_get_data( image );
+    // The pixel buffer of the initial bitmap:
+    auto bm_pix_buffer = (( BITMAP_BASE&)aBitmap).GetImageData();
+
+    // Copy the source bitmap to the cairo bitmap buffer.
+    // In cairo bitmap buffer, a RGB24 bitmap is a RGB pixel packed into a uint_32
+    // 24 low bits only are used.
+    for( int row = 0; row < h; row++ )
+    {
+        for( int col = 0; col < w; col++ )
+        {
+            // Build the RGB24 pixel:
+            uint32_t pixel = bm_pix_buffer->GetRed( col, row ) << 16;
+            pixel += bm_pix_buffer->GetGreen( col, row ) << 8;
+            pixel += bm_pix_buffer->GetBlue( col, row );
+
+            // Write the pixel to the cairo image buffer:
+            uint32_t* pix_ptr = (uint32_t*) pix_buffer;
+            *pix_ptr = pixel;
+            pix_buffer += 4;
+        }
+    }
+
+    cairo_surface_mark_dirty( image );
+    cairo_set_source_surface( currentContext, image, 0, 0 );
+    cairo_paint( currentContext );
+    cairo_surface_destroy( image );
+
+    isElementAdded = true;
+
+    cairo_restore( currentContext );
+}
+
+
 void CAIRO_GAL::ResizeScreen( int aWidth, int aHeight )
 {
     screenSize = VECTOR2I( aWidth, aHeight );

common/gal/opengl/opengl_gal.cpp

@@ -32,6 +32,7 @@
 #include <gl_context_mgr.h>
 #include <geometry/shape_poly_set.h>
 #include <text_utils.h>
+#include <bitmap_base.h>
 
 #include <macros.h>
 
@@ -899,6 +900,46 @@ void OPENGL_GAL::DrawCurve( const VECTOR2D& aStartPoint, const VECTOR2D& aContro
 }
 
 
+void OPENGL_GAL::DrawBitmap( const BITMAP_BASE& aBitmap )
+{
+    int ppi = aBitmap.GetPPI();
+    double worldIU_per_mm = 1/(worldUnitLength/2.54)/1000;
+    double pix_size_iu =  worldIU_per_mm * ( 25.4 / ppi );
+
+    Save();
+
+    // Set the pixel scaling factor:
+    currentManager->Scale( pix_size_iu, pix_size_iu, 0 );
+    // The position of the bitmap is the bitmap center.
+    // move the draw origin to the top left bitmap corner:
+    currentManager->Translate( -aBitmap.GetSizePixels().x/2, -aBitmap.GetSizePixels().y/2, 0 );
+
+    isFillEnabled = true;
+    isStrokeEnabled = false;
+
+    // The pixel buffer of the initial bitmap:
+    auto bm_pix_buffer = (( BITMAP_BASE&)aBitmap).GetImageData();
+
+    for( int row = 0; row < aBitmap.GetSizePixels().y; row++ )
+    {
+        VECTOR2D pos( 0, row );
+
+        for( int col = 0; col < aBitmap.GetSizePixels().x; col++ )
+        {
+            pos.x = col;
+            SetFillColor( COLOR4D( bm_pix_buffer->GetRed( col, row )/255.0,
+                                   bm_pix_buffer->GetGreen( col, row )/255.0,
+                                   bm_pix_buffer->GetBlue( col, row )/255.0,
+                                   1.0 ) );
+            VECTOR2D end = pos + 1.0;   // Size of the rectangle = 1 pixel
+            DrawRectangle( pos, end );
+        }
+    }
+
+    Restore();
+}
+
+
 void OPENGL_GAL::BitmapText( const wxString& aText, const VECTOR2D& aPosition,
                              double aRotationAngle )
 {

common/worksheet_viewitem.cpp

@@ -29,6 +29,7 @@
 
 #include <worksheet_viewitem.h>
 #include <worksheet_shape_builder.h>
+#include <worksheet_dataitem.h>
 #include <gal/graphics_abstraction_layer.h>
 #include <painter.h>
 #include <layers_id_colors_and_visibility.h>
@@ -119,6 +120,7 @@ void WORKSHEET_VIEWITEM::ViewDraw( int aLayer, VIEW* aView ) const
             break;
 
         case WS_DRAW_ITEM_BASE::wsg_bitmap:
+            draw( static_cast<const WS_DRAW_ITEM_BITMAP*>( item ), gal );
             break;
         }
 
@@ -198,6 +200,17 @@ void WORKSHEET_VIEWITEM::draw( const WS_DRAW_ITEM_TEXT* aItem, GAL* aGal ) const
 }
 
 
+void WORKSHEET_VIEWITEM::draw( const WS_DRAW_ITEM_BITMAP* aItem, GAL* aGal ) const
+{
+    aGal->Save();
+    VECTOR2D position = aItem->GetPosition();
+    aGal->Translate( position );
+    WORKSHEET_DATAITEM_BITMAP* parent = static_cast<WORKSHEET_DATAITEM_BITMAP*>( aItem->GetParent() );
+    aGal->DrawBitmap( *parent->m_ImageBitmap );
+    aGal->Restore();
+}
+
+
 void WORKSHEET_VIEWITEM::drawBorder( GAL* aGal ) const
 {
     VECTOR2D origin = VECTOR2D( 0.0, 0.0 );

include/gal/cairo/cairo_gal.h

@@ -137,6 +137,9 @@ public:
     virtual void DrawCurve( const VECTOR2D& startPoint, const VECTOR2D& controlPointA,
                             const VECTOR2D& controlPointB, const VECTOR2D& endPoint ) override;
 
+    /// @copydoc GAL::DrawBitmap()
+    virtual void DrawBitmap( const BITMAP_BASE& aBitmap ) override;
+
     // --------------
     // Screen methods
     // --------------

include/gal/graphics_abstraction_layer.h

@@ -41,6 +41,7 @@
 
 class SHAPE_LINE_CHAIN;
 class SHAPE_POLY_SET;
+class BITMAP_BASE;
 
 namespace KIGFX
 {
@@ -179,6 +180,11 @@ public:
     virtual void DrawCurve( const VECTOR2D& startPoint,    const VECTOR2D& controlPointA,
                             const VECTOR2D& controlPointB, const VECTOR2D& endPoint ) {};
 
+    /**
+     * @brief Draw a bitmap image.
+     */
+    virtual void DrawBitmap( const BITMAP_BASE& aBitmap ) {};
+
     // --------------
     // Screen methods
     // --------------

include/gal/opengl/opengl_gal.h

@@ -149,6 +149,9 @@ public:
     virtual void DrawCurve( const VECTOR2D& startPoint, const VECTOR2D& controlPointA,
                             const VECTOR2D& controlPointB, const VECTOR2D& endPoint ) override;
 
+    /// @copydoc GAL::DrawBitmap()
+    virtual void DrawBitmap( const BITMAP_BASE& aBitmap ) override;
+
     /// @copydoc GAL::BitmapText()
     virtual void BitmapText( const wxString& aText, const VECTOR2D& aPosition,
                              double aRotationAngle ) override;

include/worksheet_shape_builder.h

@@ -361,7 +361,7 @@ public:
      */
     virtual bool HitTestStartPoint( const wxPoint& aPosition) override;
 
-    const wxPoint GetPosition() { return m_pos; }
+    const wxPoint GetPosition() const { return m_pos; }
 };
 
 /*

include/worksheet_viewitem.h

@@ -39,6 +39,7 @@ class WS_DRAW_ITEM_LINE;
 class WS_DRAW_ITEM_RECT;
 class WS_DRAW_ITEM_POLYGON;
 class WS_DRAW_ITEM_TEXT;
+class WS_DRAW_ITEM_BITMAP;
 
 namespace KIGFX
 {
@@ -163,6 +164,7 @@ protected:
     void draw( const WS_DRAW_ITEM_RECT* aItem, GAL* aGal ) const;
     void draw( const WS_DRAW_ITEM_POLYGON* aItem, GAL* aGal ) const;
     void draw( const WS_DRAW_ITEM_TEXT* aItem, GAL* aGal ) const;
+    void draw( const WS_DRAW_ITEM_BITMAP* aItem, GAL* aGal ) const;
 
     /// Draws a border that determines the page size.
     void drawBorder( GAL* aGal ) const;