thorvg/src/lib/tvgPaint.h

/*
 * Copyright (c) 2020-2021 Samsung Electronics Co., Ltd. All rights reserved.

 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:

 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#ifndef _TVG_PAINT_H_
#define _TVG_PAINT_H_

#include <float.h>
#include <math.h>
#include "tvgRender.h"

static inline bool FLT_SAME(float a, float b)
{
    return (fabsf(a - b) < FLT_EPSILON);
}

static bool _clipPathFastTrack(Paint* cmpTarget, const RenderTransform* transform, RenderRegion& viewport)
{
    /* Access Shape class by Paint is bad... but it's ok still it's an internal usage. */
    auto shape = static_cast<Shape*>(cmpTarget);

    //Rectangle Candidates?
    const Point* pts;
     if (shape->pathCoords(&pts) != 4) return false;

    //No Rotation?
    if (transform) {
        if (transform->m.e12 != 0 || transform->m.e21 != 0 || transform->m.e11 != transform->m.e22) return false;
    }

    //Othogonal Rectangle?
    auto pt1 = pts + 0;
    auto pt2 = pts + 1;
    auto pt3 = pts + 2;
    auto pt4 = pts + 3;

    if ((FLT_SAME(pt1->x, pt2->x) && FLT_SAME(pt2->y, pt3->y) && FLT_SAME(pt3->x, pt4->x) && FLT_SAME(pt1->y, pt4->y)) ||
        (FLT_SAME(pt2->x, pt3->x) && FLT_SAME(pt1->y, pt2->y) && FLT_SAME(pt1->x, pt4->x) && FLT_SAME(pt3->y, pt4->y))) {

        auto x1 = pt1->x;
        auto y1 = pt1->y;
        auto x2 = pt3->x;
        auto y2 = pt3->y;

        if (transform) {
            x1 = x1 * transform->m.e11 + transform->m.e13;
            y1 = y1 * transform->m.e22 + transform->m.e23;
            x2 = x2 * transform->m.e11 + transform->m.e13;
            y2 = y2 * transform->m.e22 + transform->m.e23;
        }

        viewport.x = static_cast<uint32_t>(x1);
        viewport.y = static_cast<uint32_t>(y1);
        viewport.w = static_cast<uint32_t>(roundf(x2 - x1 + 0.5f));
        viewport.h = static_cast<uint32_t>(roundf(y2 - y1 + 0.5f));

        return true;
    }

    return false;
}


namespace tvg
{
    enum class PaintType { Shape = 0, Scene, Picture };

    struct StrategyMethod
    {
        virtual ~StrategyMethod() {}

        virtual bool dispose(RenderMethod& renderer) = 0;
        virtual void* update(RenderMethod& renderer, const RenderTransform* transform, uint32_t opacity, Array<RenderData>& clips, RenderUpdateFlag pFlag) = 0;   //Return engine data if it has.
        virtual bool render(RenderMethod& renderer) = 0;
        virtual bool bounds(float* x, float* y, float* w, float* h) const = 0;
        virtual RenderRegion bounds(RenderMethod& renderer) const = 0;
        virtual Paint* duplicate() = 0;
    };

    struct Paint::Impl
    {
        StrategyMethod* smethod = nullptr;
        RenderTransform *rTransform = nullptr;
        uint32_t flag = RenderUpdateFlag::None;

        Paint* cmpTarget = nullptr;
        CompositeMethod cmpMethod = CompositeMethod::None;

        uint8_t opacity = 255;

        PaintType type;

        ~Impl() {
            if (cmpTarget) delete(cmpTarget);
            if (smethod) delete(smethod);
            if (rTransform) delete(rTransform);
        }

        void method(StrategyMethod* method)
        {
            smethod = method;
        }

        bool rotate(float degree)
        {
            if (rTransform) {
                if (fabsf(degree - rTransform->degree) <= FLT_EPSILON) return true;
            } else {
                if (fabsf(degree) <= FLT_EPSILON) return true;
                rTransform = new RenderTransform();
                if (!rTransform) return false;
            }
            rTransform->degree = degree;
            if (!rTransform->overriding) flag |= RenderUpdateFlag::Transform;

            return true;
        }

        bool scale(float factor)
        {
            if (rTransform) {
                if (fabsf(factor - rTransform->scale) <= FLT_EPSILON) return true;
            } else {
                if (fabsf(factor) <= FLT_EPSILON) return true;
                rTransform = new RenderTransform();
                if (!rTransform) return false;
            }
            rTransform->scale = factor;
            if (!rTransform->overriding) flag |= RenderUpdateFlag::Transform;

            return true;
        }

        bool translate(float x, float y)
        {
            if (rTransform) {
                if (fabsf(x - rTransform->x) <= FLT_EPSILON && fabsf(y - rTransform->y) <= FLT_EPSILON) return true;
            } else {
                if (fabsf(x) <= FLT_EPSILON && fabsf(y) <= FLT_EPSILON) return true;
                rTransform = new RenderTransform();
                if (!rTransform) return false;
            }
            rTransform->x = x;
            rTransform->y = y;
            if (!rTransform->overriding) flag |= RenderUpdateFlag::Transform;

            return true;
        }

        bool transform(const Matrix& m)
        {
            if (!rTransform) {
                rTransform = new RenderTransform();
                if (!rTransform) return false;
            }
            rTransform->override(m);
            flag |= RenderUpdateFlag::Transform;

            return true;
        }

        bool bounds(float* x, float* y, float* w, float* h) const
        {
            return smethod->bounds(x, y, w, h);
        }

        RenderRegion bounds(RenderMethod& renderer) const
        {
            return smethod->bounds(renderer);
        }

        bool dispose(RenderMethod& renderer)
        {
            if (cmpTarget) cmpTarget->pImpl->dispose(renderer);
            return smethod->dispose(renderer);
        }

        void* update(RenderMethod& renderer, const RenderTransform* pTransform, uint32_t opacity, Array<RenderData>& clips, uint32_t pFlag)
        {
            if (flag & RenderUpdateFlag::Transform) {
                if (!rTransform) return nullptr;
                if (!rTransform->update()) {
                    delete(rTransform);
                    rTransform = nullptr;
                }
            }

            /* 1. Composition Pre Processing */
            void *cmpData = nullptr;
            RenderRegion viewport;
            bool cmpFastTrack = false;

            if (cmpTarget) {
                /* If transform has no rotation factors && ClipPath is a simple rectangle,
                   we can avoid regular ClipPath sequence but use viewport for performance */
                if (cmpMethod == CompositeMethod::ClipPath) {
                    RenderRegion viewport2;
                    if ((cmpFastTrack = _clipPathFastTrack(cmpTarget, pTransform, viewport2))) {
                        viewport = renderer.viewport();
                        viewport2.merge(viewport);
                        renderer.viewport(viewport2);
                    }
                }

                if (!cmpFastTrack) {
                    cmpData = cmpTarget->pImpl->update(renderer, pTransform, 255, clips, pFlag);
                    if (cmpMethod == CompositeMethod::ClipPath) clips.push(cmpData);
                }
            }

            /* 2. Main Update */
            void *edata = nullptr;
            auto newFlag = static_cast<RenderUpdateFlag>(pFlag | flag);
            flag = RenderUpdateFlag::None;
            opacity = (opacity * this->opacity) / 255;

            if (rTransform && pTransform) {
                RenderTransform outTransform(pTransform, rTransform);
                edata = smethod->update(renderer, &outTransform, opacity, clips, newFlag);
            } else {
                auto outTransform = pTransform ? pTransform : rTransform;
                edata = smethod->update(renderer, outTransform, opacity, clips, newFlag);
            }

            /* 3. Composition Post Processing */
            if (cmpFastTrack) renderer.viewport(viewport);
            else if (cmpData && cmpMethod == CompositeMethod::ClipPath) clips.pop();

            return edata;
        }

        bool render(RenderMethod& renderer)
        {
            Compositor* cmp = nullptr;

            /* Note: only ClipPath is processed in update() step.
               Create a composition image. */
            if (cmpTarget && cmpMethod != CompositeMethod::ClipPath) {
                auto region = cmpTarget->pImpl->bounds(renderer);
                if (region.w == 0 || region.h == 0) return false;
                cmp = renderer.target(region);
                renderer.beginComposite(cmp, CompositeMethod::None, 255);
                cmpTarget->pImpl->render(renderer);
            }

            if (cmp) renderer.beginComposite(cmp, cmpMethod, cmpTarget->pImpl->opacity);

            auto ret = smethod->render(renderer);

            if (cmp) renderer.endComposite(cmp);

            return ret;
        }

        Paint* duplicate()
        {
            auto ret = smethod->duplicate();
            if (!ret) return nullptr;

            //duplicate Transform
            if (rTransform) {
                ret->pImpl->rTransform = new RenderTransform();
                if (ret->pImpl->rTransform) {
                    *ret->pImpl->rTransform = *rTransform;
                    ret->pImpl->flag |= RenderUpdateFlag::Transform;
                }
            }

            ret->pImpl->opacity = opacity;

            if (cmpTarget) ret->pImpl->cmpTarget = cmpTarget->duplicate();

            ret->pImpl->cmpMethod = cmpMethod;

            return ret;
        }

        bool composite(Paint* target, CompositeMethod method)
        {
            if ((!target && method != CompositeMethod::None) || (target && method == CompositeMethod::None)) return false;
            if (cmpTarget) delete(cmpTarget);
            cmpTarget = target;
            cmpMethod = method;
            return true;
        }
    };


    template<class T>
    struct PaintMethod : StrategyMethod
    {
        T* inst = nullptr;

        PaintMethod(T* _inst) : inst(_inst) {}
        ~PaintMethod() {}

        bool bounds(float* x, float* y, float* w, float* h) const override
        {
            return inst->bounds(x, y, w, h);
        }

        RenderRegion bounds(RenderMethod& renderer) const override
        {
            return inst->bounds(renderer);
        }

        bool dispose(RenderMethod& renderer) override
        {
            return inst->dispose(renderer);
        }

        void* update(RenderMethod& renderer, const RenderTransform* transform, uint32_t opacity, Array<RenderData>& clips, RenderUpdateFlag flag) override
        {
            return inst->update(renderer, transform, opacity, clips, flag);
        }

        bool render(RenderMethod& renderer) override
        {
            return inst->render(renderer);
        }

        Paint* duplicate() override
        {
            return inst->duplicate();
        }
    };
}

#endif //_TVG_PAINT_H_