Rectangle is not Drawing Like It should be

[Logan Welty]

Trying to swap out cairo with vulkan/skia instead and I have this code:

static const gboolean on_source_image_draw(GtkWidget *widget, cairo_t *cr, gpointer user_data) {

// Want this color: #d2d2d4 rgba(219, 219, 219, 0.8)

TileGridUI *ui = (TileGridUI *)user_data;

render_data_t* state = render;

// GrVkImageInfo is used to construct GrBackendTexture and GrBackendRenderTarget objects that in turn are used to create SkSurface and SkImage objects that refer to VkImages created by the Skia client.

// Draw background

if (!draw.update_image_grid_container_drawing) {

// Get widget dimensions

dimensions.width = gtk_widget_get_allocated_width(widget);

dimensions.height = gtk_widget_get_allocated_height(widget);

std::unique_ptr<GtkAllocation> allocation = std::make_unique<GtkAllocation>();

gtk_widget_get_allocation(widget, allocation.get());

dimensions.x = allocation.get()->x; // Get x position

dimensions.y = allocation.get()->y; // Get y position

draw.update_image_grid_container_drawing = TRUE;

allocation.release();

}

strokePaint.setStyle(SkPaint::kStroke_Style); // Set the type of stroke

strokePaint.setStrokeWidth(3.0f); // Set the line width

fillPaint.setColor(SkColorSetARGB(219, 219, 219, 0.8f));

// Create an SkSurface backed by a Vulkan VkImage. Often clients will be getting VkImages from

// swapchains. In those cases they should use SkSurfaces::WrapBackendTexture or

// SkSurfaces::WrapBackendRenderTarget to wrap those premade VkImages in Skia.

SkImageInfo info = SkImageInfo::MakeN32Premul(dimensions.width, dimensions.height);

// Wrapper below self cleans

sk_sp<SkSurface> gpuSurface(

SkSurfaces::RenderTarget(context.get(), skgpu::Budgeted::kNo, info));

if (!gpuSurface) {

SkDebugf("SkSurfaces::RenderTarget returned null\n");

return FALSE;

}

SkCanvas* gpuCanvas = gpuSurface->getCanvas();

gpuCanvas->drawRect(draw.rect[0].MakeXYWH(dimensions.x, dimensions.y, dimensions.width, dimensions.height), fillPaint);

context->flush();

context->submit(); ....}

Going off of the skia user manual and I should be able to fill in the background white on my GTK widget, but I get this instead:

: (tileset_creator:18722): Gtk-WARNING **: 14:46:14.784: drawing failure for widget 'GtkDrawingArea': NULL pointer

(tileset_creator:18722): Gtk-WARNING **: 14:46:14.784: drawing failure for widget 'GtkFrame': NULL pointer

(tileset_creator:18722): Gtk-WARNING **: 14:46:14.784: drawing failure for widget 'GtkBox': NULL pointer

(tileset_creator:18722): Gtk-WARNING **: 14:46:14.784: drawing failure for widget 'GtkBox': NULL pointer

(tileset_creator:18722): Gtk-WARNING **: 14:46:14.785: drawing failure for widget 'GtkWindow': NULL pointer

I have other code that if uncommented it will work, because it is cairo and the warning will disappear. I am trying to figure out why it won't draw the rectangle white at the specified location

[Logan Welty]

Nullptr is something else, and was fixed. The issue still resides to this day.