node_composite_viewer.cc

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/* SPDX-FileCopyrightText: 2006 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */
 
#include "BLI_bounds_types.hh"
#include "BLI_math_vector_types.hh"
 
#include "BKE_global.hh"
#include "BKE_image.hh"
 
#include "RNA_access.hh"
 
#include "UI_interface.hh"
#include "UI_resources.hh"
 
#include "GPU_shader.hh"
#include "GPU_texture.hh"
 
#include "COM_node_operation.hh"
#include "COM_utilities.hh"
 
#include "node_composite_util.hh"
 
/* **************** VIEWER ******************** */
 
namespace blender::nodes::node_composite_viewer_cc {
 
static void cmp_node_viewer_declare(NodeDeclarationBuilder &b)
{
  b.add_input<decl::Color>("Image").default_value({0.0f, 0.0f, 0.0f, 1.0f});
  b.add_input<decl::Float>("Alpha").default_value(1.0f).min(0.0f).max(1.0f);
}
 
static void node_composit_init_viewer(bNodeTree * /*ntree*/, bNode *node)
{
  ImageUser *iuser = MEM_cnew<ImageUser>(__func__);
  node->storage = iuser;
  iuser->sfra = 1;
 
  node->id = (ID *)BKE_image_ensure_viewer(G.main, IMA_TYPE_COMPOSITE, "Viewer Node");
}
 
static void node_composit_buts_viewer(uiLayout *layout, bContext * /*C*/, PointerRNA *ptr)
{
  uiItemR(layout, ptr, "use_alpha", UI_ITEM_R_SPLIT_EMPTY_NAME, nullptr, ICON_NONE);
}
 
using namespace blender::realtime_compositor;
 
class ViewerOperation : public NodeOperation {
 public:
  using NodeOperation::NodeOperation;
 
  void execute() override
  {
    /* See the compute_domain method for more information on the first condition. */
    if (!context().use_composite_output() && !context().is_valid_compositing_region()) {
      return;
    }
 
    const Result &image = get_input("Image");
    const Result &alpha = get_input("Alpha");
    if (image.is_single_value() && alpha.is_single_value()) {
      execute_clear();
    }
    else if (ignore_alpha()) {
      execute_ignore_alpha();
    }
    else if (!node().input_by_identifier("Alpha")->is_logically_linked()) {
      execute_copy();
    }
    else {
      execute_set_alpha();
    }
  }
 
  /* Executes when all inputs are single values, in which case, the output texture can just be
   * cleared to the appropriate color. */
  void execute_clear()
  {
    const Result &image = get_input("Image");
    const Result &alpha = get_input("Alpha");
 
    float4 color = image.get_color_value();
    if (ignore_alpha()) {
      color.w = 1.0f;
    }
    else if (node().input_by_identifier("Alpha")->is_logically_linked()) {
      color.w = alpha.get_float_value();
    }
 
    const Domain domain = compute_domain();
    Result output = context().get_viewer_output_result(
        domain, image.meta_data.is_non_color_data, image.precision());
    if (this->context().use_gpu()) {
      GPU_texture_clear(output, GPU_DATA_FLOAT, color);
    }
    else {
      parallel_for(domain.size, [&](const int2 texel) { output.store_pixel(texel, color); });
    }
  }
 
  /* Executes when the alpha channel of the image is ignored. */
  void execute_ignore_alpha()
  {
    if (context().use_gpu()) {
      this->execute_ignore_alpha_gpu();
    }
    else {
      this->execute_ignore_alpha_cpu();
    }
  }
 
  void execute_ignore_alpha_gpu()
  {
    const Result &image = get_input("Image");
    const Domain domain = compute_domain();
    Result output = context().get_viewer_output_result(
        domain, image.meta_data.is_non_color_data, image.precision());
 
    GPUShader *shader = context().get_shader("compositor_write_output_opaque", output.precision());
    GPU_shader_bind(shader);
 
    const Bounds<int2> bounds = get_output_bounds();
    GPU_shader_uniform_2iv(shader, "lower_bound", bounds.min);
    GPU_shader_uniform_2iv(shader, "upper_bound", bounds.max);
 
    image.bind_as_texture(shader, "input_tx");
 
    output.bind_as_image(shader, "output_img");
 
    compute_dispatch_threads_at_least(shader, domain.size);
 
    image.unbind_as_texture();
    output.unbind_as_image();
    GPU_shader_unbind();
  }
 
  void execute_ignore_alpha_cpu()
  {
    const Domain domain = compute_domain();
    const Result &image = get_input("Image");
    Result output = context().get_viewer_output_result(
        domain, image.meta_data.is_non_color_data, image.precision());
 
    const Bounds<int2> bounds = get_output_bounds();
    parallel_for(domain.size, [&](const int2 texel) {
      const int2 output_texel = texel + bounds.min;
      if (output_texel.x > bounds.max.x || output_texel.y > bounds.max.y) {
        return;
      }
      output.store_pixel(texel + bounds.min, float4(image.load_pixel(texel).xyz(), 1.0f));
    });
  }
 
  /* Executes when the image texture is written with no adjustments and can thus be copied directly
   * to the output. */
  void execute_copy()
  {
    if (context().use_gpu()) {
      this->execute_copy_gpu();
    }
    else {
      this->execute_copy_cpu();
    }
  }
 
  void execute_copy_gpu()
  {
    const Result &image = get_input("Image");
    const Domain domain = compute_domain();
    Result output = context().get_viewer_output_result(
        domain, image.meta_data.is_non_color_data, image.precision());
 
    GPUShader *shader = context().get_shader("compositor_write_output", output.precision());
    GPU_shader_bind(shader);
 
    const Bounds<int2> bounds = get_output_bounds();
    GPU_shader_uniform_2iv(shader, "lower_bound", bounds.min);
    GPU_shader_uniform_2iv(shader, "upper_bound", bounds.max);
 
    image.bind_as_texture(shader, "input_tx");
 
    output.bind_as_image(shader, "output_img");
 
    compute_dispatch_threads_at_least(shader, domain.size);
 
    image.unbind_as_texture();
    output.unbind_as_image();
    GPU_shader_unbind();
  }
 
  void execute_copy_cpu()
  {
    const Domain domain = compute_domain();
    const Result &image = get_input("Image");
    Result output = context().get_viewer_output_result(
        domain, image.meta_data.is_non_color_data, image.precision());
 
    const Bounds<int2> bounds = get_output_bounds();
    parallel_for(domain.size, [&](const int2 texel) {
      const int2 output_texel = texel + bounds.min;
      if (output_texel.x > bounds.max.x || output_texel.y > bounds.max.y) {
        return;
      }
      output.store_pixel(texel + bounds.min, image.load_pixel(texel));
    });
  }
 
  /* Executes when the alpha channel of the image is set as the value of the input alpha. */
  void execute_set_alpha()
  {
    if (context().use_gpu()) {
      execute_set_alpha_gpu();
    }
    else {
      execute_set_alpha_cpu();
    }
  }
 
  void execute_set_alpha_gpu()
  {
    const Result &image = get_input("Image");
    const Domain domain = compute_domain();
    Result output = context().get_viewer_output_result(
        domain, image.meta_data.is_non_color_data, image.precision());
 
    GPUShader *shader = context().get_shader("compositor_write_output_alpha", output.precision());
    GPU_shader_bind(shader);
 
    const Bounds<int2> bounds = get_output_bounds();
    GPU_shader_uniform_2iv(shader, "lower_bound", bounds.min);
    GPU_shader_uniform_2iv(shader, "upper_bound", bounds.max);
 
    image.bind_as_texture(shader, "input_tx");
 
    const Result &alpha = get_input("Alpha");
    alpha.bind_as_texture(shader, "alpha_tx");
 
    output.bind_as_image(shader, "output_img");
 
    compute_dispatch_threads_at_least(shader, domain.size);
 
    image.unbind_as_texture();
    alpha.unbind_as_texture();
    output.unbind_as_image();
    GPU_shader_unbind();
  }
 
  void execute_set_alpha_cpu()
  {
    const Domain domain = compute_domain();
    const Result &image = get_input("Image");
    const Result &alpha = get_input("Alpha");
    Result output = context().get_viewer_output_result(
        domain, image.meta_data.is_non_color_data, image.precision());
 
    const Bounds<int2> bounds = get_output_bounds();
    parallel_for(domain.size, [&](const int2 texel) {
      const int2 output_texel = texel + bounds.min;
      if (output_texel.x > bounds.max.x || output_texel.y > bounds.max.y) {
        return;
      }
      output.store_pixel(texel + bounds.min,
                         float4(image.load_pixel(texel).xyz(), alpha.load_pixel(texel).x));
    });
  }
 
  /* Returns the bounds of the area of the compositing region. If the context can use the composite
   * output and thus has a dedicated viewer of an arbitrary size, then use the input in its
   * entirety. Otherwise, no dedicated viewer exist so only write into the compositing region,
   * which might be limited to a smaller region of the output texture. */
  Bounds<int2> get_output_bounds()
  {
    if (context().use_composite_output()) {
      return Bounds<int2>(int2(0), compute_domain().size);
    }
 
    const rcti compositing_region = context().get_compositing_region();
    return Bounds<int2>(int2(compositing_region.xmin, compositing_region.ymin),
                        int2(compositing_region.xmax, compositing_region.ymax));
  }
 
  /* If true, the alpha channel of the image is set to 1, that is, it becomes opaque. If false, the
   * alpha channel of the image is retained, but only if the alpha input is not linked. If the
   * alpha input is linked, it the value of that input will be used as the alpha of the image. */
  bool ignore_alpha()
  {
    return bnode().custom2 & CMP_NODE_OUTPUT_IGNORE_ALPHA;
  }
 
  Domain compute_domain() override
  {
    /* The context can use the composite output and thus has a dedicated viewer of an arbitrary
     * size, so use the input directly. Otherwise, no dedicated viewer exist so the input should be
     * in the domain of the compositing region. */
    if (context().use_composite_output()) {
      const Domain domain = NodeOperation::compute_domain();
      /* Fallback to the compositing region size in case of a single value domain. */
      return domain.size == int2(1) ? Domain(context().get_compositing_region_size()) : domain;
    }
    else {
      return Domain(context().get_compositing_region_size());
    }
  }
};
 
static NodeOperation *get_compositor_operation(Context &context, DNode node)
{
  return new ViewerOperation(context, node);
}
 
}  // namespace blender::nodes::node_composite_viewer_cc
 
void register_node_type_cmp_viewer()
{
  namespace file_ns = blender::nodes::node_composite_viewer_cc;
 
  static blender::bke::bNodeType ntype;
 
  cmp_node_type_base(&ntype, CMP_NODE_VIEWER, "Viewer", NODE_CLASS_OUTPUT);
  ntype.declare = file_ns::cmp_node_viewer_declare;
  ntype.draw_buttons = file_ns::node_composit_buts_viewer;
  ntype.initfunc = file_ns::node_composit_init_viewer;
  blender::bke::node_type_storage(
      &ntype, "ImageUser", node_free_standard_storage, node_copy_standard_storage);
  ntype.get_compositor_operation = file_ns::get_compositor_operation;
 
  ntype.no_muting = true;
 
  blender::bke::node_register_type(&ntype);
}