TexgenNode.hpp

#pragma once
 
#include <Gfx/Graph/Node.hpp>
#include <Gfx/Graph/NodeRenderer.hpp>
#include <Gfx/Graph/RenderList.hpp>
#include <Gfx/Graph/RenderState.hpp>
#include <Gfx/Graph/Uniforms.hpp>
 
namespace score::gfx
{
 
struct TexgenNode : NodeModel
{
  static const constexpr auto vertex = R"_(#version 450
  layout(location = 0) in vec2 position;
  layout(location = 1) in vec2 texcoord;
 
  layout(binding = 3) uniform sampler2D y_tex;
  layout(location = 0) out vec2 v_texcoord;
 
  layout(std140, binding = 0) uniform renderer_t {
    mat4 clipSpaceCorrMatrix;
    vec2 renderSize;
  } renderer;
 
  out gl_PerVertex { vec4 gl_Position; };
 
  void main()
  {
    v_texcoord = texcoord;
    gl_Position = renderer.clipSpaceCorrMatrix * vec4(position.xy, 0.0, 1.);
// The uploaded buffer's row 0 is its top, and it must come out at the top on
// every backend. Vulkan was left out of this correction, so a JIT Texgen -- and
// anything else painting a texture from C++ -- came out upside down there,
// through every sink: the window, the readback outputs and the GPU encoders
// alike.
#if !(defined(QSHADER_HLSL) || defined(QSHADER_MSL))
  gl_Position.y = - gl_Position.y;
#endif
  }
  )_";
 
  static const constexpr auto filter = R"_(#version 450
  layout(location = 0) in vec2 v_texcoord;
  layout(location = 0) out vec4 fragColor;
 
  layout(std140, binding = 0) uniform renderer_t {
  mat4 clipSpaceCorrMatrix;
  vec2 renderSize;
  } renderer;
 
  layout(binding=3) uniform sampler2D y_tex;
 
 
  void main ()
  {
    fragColor = texture(y_tex, v_texcoord);
  }
  )_";
 
  struct ubo
  {
    int currentImageIndex{};
    float pad;
    float position[2];
  } ubo;
 
  struct Rendered : GenericNodeRenderer
  {
    using GenericNodeRenderer::GenericNodeRenderer;
 
    ~Rendered() { }
 
    QRhiTexture* texture{};
    void initState(RenderList& renderer, QRhiResourceUpdateBatch& res) override
    {
      m_mesh = &renderer.defaultTriangle();
      defaultMeshInit(renderer, *m_mesh, res);
      processUBOInit(renderer);
      m_material.init(renderer, node.input, m_samplers);
      std::tie(m_vertexS, m_fragmentS)
          = score::gfx::makeShaders(renderer.state, vertex, filter);
 
      auto& rhi = *renderer.state.rhi;
      {
        vec.resize(640 * 480 * 4);
        texture = rhi.newTexture(
            QRhiTexture::RGBA8, QSize(640, 480), 1, QRhiTexture::Flag{});
 
        texture->create();
      }
 
      {
        auto sampler = rhi.newSampler(
            QRhiSampler::Linear, QRhiSampler::Linear, QRhiSampler::None,
            QRhiSampler::ClampToEdge, QRhiSampler::ClampToEdge);
 
        sampler->create();
        m_samplers.push_back({sampler, texture});
      }
 
      m_initialized = true;
    }
 
    void update(
        RenderList& renderer, QRhiResourceUpdateBatch& res,
        score::gfx::Edge* edge) override
    {
      if(!edge)
        return;
 
      auto& n = const_cast<TexgenNode&>(static_cast<const TexgenNode&>(this->node));
      defaultUBOUpdate(renderer, res);
      auto sz = renderer.renderSize(edge);
      auto bytes = sz.width() * sz.height() * 4;
      if(bytes != vec.size())
      {
        vec.resize(bytes, boost::container::default_init);
 
        QRhiTexture* oldtex = texture;
        QRhiTexture* newtex = renderer.state.rhi->newTexture(
            QRhiTexture::RGBA8, sz, 1, QRhiTexture::Flag{});
        newtex->create();
        for(auto& [edge, pass] : this->m_p)
          if(pass.p.srb)
            score::gfx::replaceTexture(*pass.p.srb, m_samplers[0].sampler, newtex);
        texture = newtex;
 
        if(oldtex && oldtex != &renderer.emptyTexture())
        {
          oldtex->deleteLater();
        }
      }
 
      if(func_t f = n.function.load())
      {
        f(vec.data(), sz.width(), sz.height(), t++);
 
        QRhiTextureSubresourceUploadDescription subdesc{
            QByteArray::fromRawData((const char*)vec.data(), vec.size())};
        QRhiTextureUploadEntry entry{0, 0, subdesc};
        QRhiTextureUploadDescription desc{entry};
 
        res.uploadTexture(texture, desc);
      }
    }
 
    void releaseState(RenderList& r) override
    {
      if(texture)
      {
        texture->deleteLater();
        texture = nullptr;
      }
 
      GenericNodeRenderer::releaseState(r);
    }
 
    int t = 0;
    boost::container::vector<unsigned char> vec;
  };
 
  TexgenNode() { output.push_back(new Port{this, {}, Types::Image, {}}); }
  virtual ~TexgenNode()
  {
    m_materialData.release();
  }
 
  using func_t = void (*)(unsigned char* rgb, int width, int height, int t);
  std::atomic<func_t> function{};
 
  score::gfx::NodeRenderer* createRenderer(RenderList& r) const noexcept override
  {
    return new Rendered{*this};
  }
};
 
 
}