TextureToBuffer.hpp

#pragma once
 
#include <ossia/detail/pod_vector.hpp>
#include <Threedim/GeometryToBufferStrategies.hpp>
 
#include <boost/container/vector.hpp>
 
#include <halp/controls.hpp>
#include <halp/geometry.hpp>
#include <halp/meta.hpp>
#include <halp/texture.hpp>
#include <halp/buffer.hpp>
#include <halp/texture.hpp>
 
namespace Threedim
{
class TextureToBuffer
{
public:
  halp_meta(name, "Texture to buffer")
  halp_meta(category, "Visuals/Utilities")
  halp_meta(c_name, "texture_to_buffer")
  halp_meta(description, "Copy texture pixel data into a GPU buffer for further processing.")
  halp_meta(manual_url, "https://ossia.io/score-docs/processes/texture-to-buffer.html")
  halp_meta(uuid, "fd7d6339-c745-4733-a1c2-6ebd0a25fd92")
 
  struct ins
  {
    halp::texture_input<"Texture", halp::custom_variable_texture> texture;
  } inputs;
  struct
  {
    halp::gpu_buffer_output<"Buffer"> buffer;
  } outputs;
 
  QRhiBuffer* buf{};
  void init(score::gfx::RenderList& renderer, QRhiResourceUpdateBatch& res)
  {
    outputs.buffer.buffer.handle = nullptr;
    outputs.buffer.buffer.byte_size = 0;
    outputs.buffer.buffer.byte_offset = 0;
    outputs.buffer.buffer.changed = true;
 
    if(!inputs.texture.texture.bytes)
      return;
    auto bytes = inputs.texture.texture.bytesize();
 
    if(buf)
      renderer.releaseBuffer(buf);
    if(bytes <= 0)
      return;
 
    buf = renderer.state.rhi->newBuffer(QRhiBuffer::Static, QRhiBuffer::StorageBuffer | QRhiBuffer::VertexBuffer, bytes);
    if(!buf->create())
    {
      delete buf;
      buf = nullptr;
      return;
    }
 
    outputs.buffer.buffer.handle = buf;
    outputs.buffer.buffer.byte_size = bytes;
    outputs.buffer.buffer.byte_offset = 0;
    outputs.buffer.buffer.changed = true;
  }
 
  void update(
      score::gfx::RenderList& renderer, QRhiResourceUpdateBatch& res,
      score::gfx::Edge* e)
  {
    if(!buf || inputs.texture.texture.bytesize() != buf->size())
    {
      init(renderer, res);
      return;
    }
    // A dropout tick (bytes == nullptr) re-inits and zeroes the
    // published outlet while keeping `buf` alive. When the source comes
    // back at the SAME size no re-init happens, so republish the
    // still-live, size-matching buffer — otherwise the outlet stays
    // null forever while runInitialPasses() uploads into a buffer
    // downstream can no longer see.
    if(inputs.texture.texture.bytes && outputs.buffer.buffer.handle != buf)
    {
      outputs.buffer.buffer.handle = buf;
      outputs.buffer.buffer.byte_size = buf->size();
      outputs.buffer.buffer.byte_offset = 0;
      outputs.buffer.buffer.changed = true;
    }
  }
 
  void release(score::gfx::RenderList& r)
  {
    // The buffer is ours: without this, every renderer release (each undo /
    // redo that recreates the node, a QRhi teardown) leaked it, and Vulkan's
    // allocator asserted "Some allocations were not freed" when the QRhi
    // went away (examples/3d/extract-attribute.score).
    if(buf)
      r.releaseBuffer(buf);
    buf = nullptr;
    outputs.buffer.buffer.handle = nullptr;
    outputs.buffer.buffer.byte_size = 0;
    outputs.buffer.buffer.changed = true;
  }
 
  void runInitialPasses(
      score::gfx::RenderList& renderer, QRhiCommandBuffer& commands,
      QRhiResourceUpdateBatch*& res, score::gfx::Edge& edge)
  {
    if(!inputs.texture.texture.bytes)
      return;
    if(!buf)
      return;
    auto sz = buf->size();
    if(inputs.texture.texture.bytesize() != sz)
      return;
 
 
    res->uploadStaticBuffer(
        buf,
        QByteArray::fromRawData((const char*)inputs.texture.texture.bytes, sz));
  }
};
 
}