GU_OnionSkin.h

Go to the documentation of this file.

/*
 * PROPRIETARY INFORMATION.  This software is proprietary to
 * Side Effects Software Inc., and is not to be reproduced,
 * transmitted, or disclosed in any way without written permission.
 *
 * NAME:        GU library (C++)
 *
 * COMMENTS:    Onion Skin Utility
 */

#pragma once

#include "GU_API.h"

#include <CH/CH_Manager.h>

#include <UT/UT_Array.h>
#include <UT/UT_Assert.h>
#include <UT/UT_Color.h>
#include <UT/UT_Debug.h>
#include <UT/UT_Optional.h>
#include <UT/UT_Vector4.h>

/// Info about when a primitive representing a single onion skin should be
/// evaluated. This structure is stored on a GT primitive to query its
/// evaluation time.
struct GU_API GU_OnionSkinPrimEvalInfo
{
    fpreal      myEvalTime = 0.0f;
    bool        myIsEvalTimeRelative = true;

    fpreal      getEvalTime(fpreal time)
                {
                    if (myIsEvalTimeRelative)
                        return time + myEvalTime;
                    else
                        return myEvalTime;
                }
};

/// Info about how a primitive representing a single onion skin should look/be
/// rendered. This structure is stored on a GR primitive to make it render
/// like an onion skin. It is also stored on a GT primitive to pass along to the
/// GR primitive.
struct GU_API GU_OnionSkinPrimRenderInfo
{
    enum class RenderMode
    {
        /// Use the viewport's render mode.
        DEFAULT,
        /// Force wireframe render.
        WIREFRAME,
        /// Force outline render.
        OUTLINE
    };

    /// RGBA tint color.
    UT_Vector4F myColor = UT_Vector4F(1.0f, 1.0f, 1.0f, 1.0f);
    RenderMode  myRenderMode = RenderMode::DEFAULT;
    /// Used for outline thickness if `myRenderMode` is `OUTLINE`.
    fpreal32    myThickness = 0.0f;
    /// Used to determine multisample index. Ideally neighbouring onion skins
    /// have indices `myIdx - 1` and `myIdx + 1` to minimize artifacts from
    /// rendering, though this is not always easy to achieve.
    exint       myIdx = 0;
};

/// One of these exists for each onion skin primitive. These are created
/// based on onion skin options and control how a specific skin is evaluated and
/// how it looks.
/// @see GU_OnionSkinOptions::makePrimInfo
struct GU_API GU_OnionSkinPrimInfo
{
    GU_OnionSkinPrimEvalInfo    myEvalInfo;
    GU_OnionSkinPrimRenderInfo  myRenderInfo;
};

/// Onion skin options that are in the viewport common display options.
/// Not specific to any onion skinned primitive in particular.
struct GU_API GU_CommonOnionSkinOptions
{
    exint       myFrameIncrement = 0;
    exint       myPreFrameCount = 0;
    exint       myPostFrameCount = 0;
    UT_Color    myPreFrameColor = UT_Color(UT_RGB, 1, 1, 1);
    UT_Color    myPostFrameColor = UT_Color(UT_RGB, 1, 1, 1);
    fpreal      myAlpha = 0.5;

    exint       getNumOnionSkins() const
                { return myPreFrameCount + myPostFrameCount; }
};

/// Options for how a single primitive should be onion skinned.
/// For example, how many onion skins a character shape primitive has.
struct GU_API GU_OnionSkinOptions
{
    struct PerSkinOptions
    {
        using RenderMode = GU_OnionSkinPrimRenderInfo::RenderMode;

        exint               myFrame;
        bool                myIsFrameRelative = true;
        UT_Color            myColor = UT_Color(UT_RGB, 1, 1, 1);
        fpreal              myAlpha = 0.5;
        RenderMode          myRenderMode = RenderMode::DEFAULT;
        fpreal32            myThickness = 1.0;
    };

    bool                        myUseCommonSkins = true;
    UT_Array<PerSkinOptions>    myExtraSkins;

    exint                   getNumOnionSkins(
                                const GU_CommonOnionSkinOptions &opts) const
                            {
                                exint num = myExtraSkins.size();
                                if (myUseCommonSkins)
                                    num += opts.getNumOnionSkins();
                                return num;
                            }

    GU_OnionSkinPrimInfo    makePrimInfo(
                                const GU_CommonOnionSkinOptions &opts,
                                exint idx) const;
};