Use the cairo-compatible basebmp surface for headless

That way the conversion from basebmp to cairo becomes unnecessary on blitting
the thing onto a cairo surface for gtk3 and opens a route to using cairo, e.g.
especially for text, to render to basebmp surfaces.

Change-Id: I1d11f503410af9c92a97018e9ee20045412b157e

2 files changed, 37 insertions, 61 deletions

diff --git a/vcl/unx/gtk/window/gtksalframe.cxx b/vcl/unx/gtk/window/gtksalframe.cxx
index ebc038ccb123..997b9482a879 100644
--- a/vcl/unx/gtk/window/gtksalframe.cxx
+++ b/vcl/unx/gtk/window/gtksalframe.cxx
@@ -1966,8 +1966,11 @@ void GtkSalFrame::AllocateFrame()
         if( aFrameSize.getY() == 0 )
             aFrameSize.setY( 1 );
         sal_Int32 nStride(basebmp::getBitmapDeviceStrideForWidth(basebmp::FORMAT_TWENTYFOUR_BIT_TC_MASK, aFrameSize.getX()));
+        int cairo_stride = cairo_format_stride_for_width(CAIRO_FORMAT_RGB24, aFrameSize.getX());
+        assert(cairo_stride >= basebmp::getBitmapDeviceStrideForWidth(basebmp::FORMAT_THIRTYTWO_BIT_TC_MASK_BGRX,
+            aFrameSize.getX()));
         m_aFrame = basebmp::createBitmapDevice(aFrameSize, true,
-                                               basebmp::FORMAT_TWENTYFOUR_BIT_TC_MASK, nStride);
+                                               basebmp::FORMAT_THIRTYTWO_BIT_TC_MASK_BGRX, cairo_stride);
         m_aFrame->setDamageTracker(
             basebmp::IBitmapDeviceDamageTrackerSharedPtr(new DamageTracker(*this)) );
         fprintf( stderr, "allocated m_aFrame size of %dx%d \n",
@@ -3423,41 +3426,28 @@ void GtkSalFrame::renderArea( cairo_t *cr, cairo_rectangle_t *area )
 
     cairo_save( cr );
 
-    int cairo_stride = cairo_format_stride_for_width (CAIRO_FORMAT_ARGB32, area->width);
-    unsigned char *p, *src, *mem = (unsigned char *)malloc (cairo_stride * area->height);
-    p = mem;
-    src = data.get();
-    src += (int)ay * nStride + (int)ax * 3;
-
-    for (int y = 0; y < aheight; ++y)
-    {
-        for (int x = 0; x < awidth; ++x)
-        {
-            p[x*4 + 0] = src[x*3 + 0]; // B
-            p[x*4 + 1] = src[x*3 + 1]; // G
-            p[x*4 + 2] = src[x*3 + 2]; // R
-            p[x*4 + 3] = 255; // A
-        }
-        src += nStride;
-        p += cairo_stride;
-    }
+    unsigned char *src = data.get();
+    assert(cairo_format_stride_for_width(CAIRO_FORMAT_RGB24, size.getX()) == nStride);
     cairo_surface_t *pSurface =
-        cairo_image_surface_create_for_data( mem,
-                                             CAIRO_FORMAT_ARGB32,
-                                             awidth, aheight,
-                                             cairo_stride );
-    /*    g_warning( "Fixed cairo status %d %d strides: %d vs %d, mask %d\n",
+        cairo_image_surface_create_for_data(src,
+                                            CAIRO_FORMAT_RGB24,
+                                            size.getX(), size.getY(),
+                                            nStride);
+    /*
+        int cairo_stride = cairo_format_stride_for_width(CAIRO_FORMAT_RGB24, size.getX());
+        g_warning( "Fixed cairo status %d %d strides: %d vs %d, mask %d\n",
                (int) cairo_status( cr ),
                (int) cairo_surface_status( pSurface ),
                (int) nStride,
                (int) cairo_stride,
-               (int) (cairo_stride & (sizeof (uint32_t)-1)) ); */
+               (int) (cairo_stride & (sizeof (uint32_t)-1)) );
+    */
 
     cairo_set_operator( cr, CAIRO_OPERATOR_OVER );
-    cairo_set_source_surface( cr, pSurface, ax, ay );
-    cairo_paint( cr );
+    cairo_set_source_surface( cr, pSurface, 0, 0 );
+    cairo_rectangle( cr, ax, ay, awidth, aheight );
+    cairo_fill( cr );
     cairo_surface_destroy( pSurface );
-    free (mem);
     cairo_restore( cr );
 
     // Render red rectangles to show what was re-rendered ...
diff --git a/vcl/unx/gtk3/gdi/gtk3salnativewidgets-gtk.cxx b/vcl/unx/gtk3/gdi/gtk3salnativewidgets-gtk.cxx
index ac708fc5e1b7..3e67f0d48405 100644
--- a/vcl/unx/gtk3/gdi/gtk3salnativewidgets-gtk.cxx
+++ b/vcl/unx/gtk3/gdi/gtk3salnativewidgets-gtk.cxx
@@ -912,7 +912,6 @@ bool GtkSalGraphics::drawNativeControl( ControlType nType, ControlPart nPart, co
     cairo_surface_t* surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32,
                                                           translatedRegion.width, translatedRegion.height);
     cairo_t *cr = cairo_create(surface);
-    cairo_surface_destroy(surface); // unref
 
     gtk_style_context_save(context);
     gtk_style_context_set_state(context, flags);
@@ -960,18 +959,15 @@ bool GtkSalGraphics::drawNativeControl( ControlType nType, ControlPart nPart, co
         break;
     }
 
-    gtk_style_context_restore(context);
-
-    renderAreaToPix(cr, &translatedRegion);
+    cairo_surface_flush(surface); //remove in a bit
     cairo_destroy(cr); // unref
+    renderAreaToPix(surface, &translatedRegion);
+    cairo_surface_destroy(surface); // unref
 
     return true;
 }
 
-// FIXME: This is incredibly lame... but so is cairo's insistence on - exactly -
-// its own stride - neither more nor less - particularly not more aligned
-// we like 8byte aligned, it likes 4 - most odd.
-void GtkSalGraphics::renderAreaToPix( cairo_t *cr,
+void GtkSalGraphics::renderAreaToPix( cairo_surface_t *source,
                                       cairo_rectangle_int_t *region)
 {
     if( !mpFrame->m_aFrame.get() )
@@ -982,33 +978,23 @@ void GtkSalGraphics::renderAreaToPix( cairo_t *cr,
     sal_Int32 nStride = mpFrame->m_aFrame->getScanlineStride();
     long ax = region->x;
     long ay = region->y;
-    long awidth = region->width;
-
-    /* Get the cairo surface and the data */
-    cairo_surface_t* surface = cairo_get_target(cr);
-    g_assert(surface != NULL);
-    cairo_surface_flush(surface);
-    unsigned char* cairo_data = cairo_image_surface_get_data(surface);
-    g_assert(cairo_data != NULL);
-    int cairo_stride = cairo_format_stride_for_width (CAIRO_FORMAT_ARGB32, awidth);
-
-    unsigned char *src = data.get();
-    src += (int)ay * nStride + (int)ax * 3;
-    awidth = MIN (region->width, size.getX() - ax);
+    long awidth = MIN (region->width, size.getX() - ax);
     long aheight = MIN (region->height, size.getY() - ay);
 
-    for (int y = 0; y < aheight; ++y)
-    {
-        for (int x = 0; x < awidth && y < aheight; ++x)
-        {
-            double alpha = ((float)cairo_data[x*4 + 3])/255.0;
-            src[x*3 + 0] = src[x*3 + 0] * (1.0 - alpha) + cairo_data[x*4+0];
-            src[x*3 + 1] = src[x*3 + 1] * (1.0 - alpha) + cairo_data[x*4+1];
-            src[x*3 + 2] = src[x*3 + 2] * (1.0 - alpha) + cairo_data[x*4+2];
-        }
-        src += nStride;
-        cairo_data += cairo_stride;
-    }
+    cairo_surface_t *target =
+        cairo_image_surface_create_for_data(data.get(),
+                                        CAIRO_FORMAT_RGB24,
+                                        size.getX(), size.getY(),
+                                        nStride);
+    cairo_t *cr = cairo_create(target);
+
+    cairo_set_source_surface( cr, source, ax, ay );
+    cairo_rectangle( cr, ax, ay, awidth, aheight );
+    cairo_fill( cr );
+    cairo_destroy(cr);
+    cairo_surface_flush(target);
+    cairo_surface_destroy(target);
+
     if ( !mpFrame->isDuringRender() )
         gtk_widget_queue_draw_area( mpFrame->getWindow(), ax, ay, awidth, aheight );
 }