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test/source/blender/compositor/COM_render_context.hh

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/* SPDX-FileCopyrightText: 2023 Blender Authors
*
* SPDX-License-Identifier: GPL-2.0-or-later */
#pragma once
#include <memory>
#include <string>
#include "BLI_map.hh"
#include "BLI_math_vector_types.hh"
#include "DNA_scene_types.h"
struct RenderResult;
namespace blender::compositor {
/* ------------------------------------------------------------------------------------------------
* File Output
*
* A FileOutput represents an image that will be saved to a file output. The image is internally
* stored as a RenderResult and saved at the path according to the image format. The image can
* either be saved as an EXR image or a non-EXR image, specified by the format. This is important
* because EXR images needs to constructed differently from other image types as will be explained
* in the following sections.
*
* For EXR images, the render result needs to be composed of passes for each layer, so the add_pass
* method should be called to add each of the passes. Additionally, an empty view should be added
* for each of the views referenced by the passes, using the single-argument overload of the
* add_view method. Those views are merely empty structure and does not hold any data aside from
* the view name. An exception to this rule is stereo EXR images, which needs to have the same
* structure as non-EXR images as explained in the following section.
*
* For non-EXR images, the render result needs to composed of views, so the multi-argument overload
* of the method add_view should be used to add each view.
*
* Color management will be applied on the images if save_as_render_ is true.
*
* Meta data can be added using the add_meta_data function. */
class FileOutput {
private:
std::string path_;
ImageFormatData format_;
RenderResult *render_result_;
bool save_as_render_;
Map<std::string, std::string> meta_data_;
public:
/* Allocate and initialize the internal render result of the file output using the give
* parameters. See the implementation for more information. */
FileOutput(const std::string &path,
const ImageFormatData &format,
int2 size,
bool save_as_render);
/* Free the internal render result. */
~FileOutput();
/* Add an empty view with the given name. An empty view is just structure and does not hold any
* data aside from the view name. This should be called for each view referenced by passes. This
* should only be called for EXR images. */
void add_view(const char *view_name);
/* Add a view of the given name that stores the given pixel buffer composed of the given number
* of channels. */
void add_view(const char *view_name, int channels, float *buffer);
/* Add a pass of the given name in the given view that stores the given pixel buffer composed of
* each of the channels given by the channels string. The channels string should contain a
* character for each channel in the pixel buffer representing the channel ID. This should only
* be called for EXR images. The given view name should be the name of an added view using the
* add_view method. */
void add_pass(const char *pass_name, const char *view_name, const char *channels, float *buffer);
/* Add meta data that will eventually be saved to the file if the format supports it. */
void add_meta_data(std::string key, std::string value);
/* Save the file to the path along with its meta data, reporting any reports to the standard
* output. */
void save(Scene *scene);
};
/* ------------------------------------------------------------------------------------------------
* Render Context
*
* A render context is created by the render pipeline and passed to the compositor to stores data
* that is specifically related to the rendering process. In particular, since the compositor is
* executed for each view separately and consecutively, it can be used to store and accumulate
* data from each of the evaluations of each view, for instance, to save all views in a single file
* for the File Output node, see the file_outputs_ member for more information. */
class RenderContext {
private:
/* A mapping between file outputs and their image file paths. Those are constructed in the
* get_file_output method and saved in the save_file_outputs method. See those methods for more
* information. */
Map<std::string, std::unique_ptr<FileOutput>> file_outputs_;
public:
/* Check if there is an available file output with the given path in the context, if one exists,
* return it, otherwise, return a newly created one from the given parameters and add it to the
* context. The arguments are ignored if the file output already exist. This method is typically
* called in the File Output nodes in the compositor.
*
* Since the compositor gets executed multiple times for each view, for single view renders, the
* file output will be constructed and fully initialized in the same compositor evaluation. For
* multi-view renders, the file output will be constructed in the evaluation of the first view,
* and each view will subsequently add its data until the file output is fully initialized in the
* last view. The render pipeline code will then call the save_file_outputs method after all
* views were evaluated to write the file outputs. */
FileOutput &get_file_output(std::string path,
ImageFormatData format,
int2 size,
bool save_as_render);
/* Write the file outputs that were added to the context. The render pipeline code should call
* this method after all views were evaluated to write the file outputs. See the get_file_output
* method for more information. */
void save_file_outputs(Scene *scene);
};
} // namespace blender::compositor