Update blit uniform by direct mapping

Author: floppyhammer

demo/android/app/src/main/cpp/native_engine.cpp

@@ -30,8 +30,6 @@ void NativeEngine::draw_frame() {
 
     auto surface = pf_swapchain->get_surface_texture();
 
-    pf_blit->update_uniform(encoder);
-
     // Swap chain render pass.
     {
         encoder->begin_render_pass(pf_swapchain->get_render_pass(), surface, Pathfinder::ColorF(0.2, 0.2, 0.2, 1.0));

demo/native/main.cpp

@@ -65,8 +65,6 @@ int main() {
 
         auto encoder = device->create_command_encoder("main encoder");
 
-        blit->update_uniform(encoder);
-
         // Swap chain render pass.
         {
             auto surface_texture = swap_chain->get_surface_texture();

pathfinder/utils/blit.cpp

@@ -50,7 +50,7 @@ void Blit::set_texture(const std::shared_ptr<Texture> &new_texture) {
     });
 }
 
-void Blit::update_uniform(const std::shared_ptr<CommandEncoder> &encoder) {
+void Blit::draw(const std::shared_ptr<CommandEncoder> &encoder) {
     if (!uniform_buffer_) {
         auto descriptor =
             BufferDescriptor{BufferType::Uniform, 4 * sizeof(float), MemoryProperty::HostVisibleAndCoherent};
@@ -62,13 +62,11 @@ void Blit::update_uniform(const std::shared_ptr<CommandEncoder> &encoder) {
             flip_y = -1.0f;
         }
 
-        encoder->write_buffer(uniform_buffer_, 0, sizeof(float), &flip_y);
+        uniform_buffer_->upload_via_mapping(sizeof(float), 0, &flip_y);
 
         descriptor_set_->add_or_update({Descriptor::uniform(0, uniform_buffer_)});
     }
-}
 
-void Blit::draw(const std::shared_ptr<CommandEncoder> &encoder) const {
     encoder->bind_render_pipeline(pipeline_);
 
     encoder->bind_descriptor_set(descriptor_set_);

pathfinder/utils/blit.h

@@ -14,9 +14,7 @@ class Blit {
 
     void set_texture(const std::shared_ptr<Texture> &new_texture);
 
-    void update_uniform(const std::shared_ptr<CommandEncoder> &encoder);
-
-    void draw(const std::shared_ptr<CommandEncoder> &encoder) const;
+    void draw(const std::shared_ptr<CommandEncoder> &encoder);
 
 private:
     std::shared_ptr<Device> device_;