thorvg/src/lib/tvgRender.h

/*
 * Copyright (c) 2020 - 2023 the ThorVG project. 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_RENDER_H_
#define _TVG_RENDER_H_

#include "tvgCommon.h"
#include "tvgArray.h"

namespace tvg
{

enum RenderUpdateFlag {None = 0, Path = 1, Color = 2, Gradient = 4, Stroke = 8, Transform = 16, Image = 32, GradientStroke = 64, All = 255};

struct Surface
{
    //TODO: Union for multiple types
    uint32_t* buffer;
    uint32_t  stride;
    uint32_t  w, h;
    uint32_t  cs;
};

using RenderData = void*;

struct Compositor
{
    CompositeMethod method;
    uint32_t        opacity;
};

struct RenderRegion
{
    int32_t x, y, w, h;

    void intersect(const RenderRegion& rhs)
    {
        auto x1 = x + w;
        auto y1 = y + h;
        auto x2 = rhs.x + rhs.w;
        auto y2 = rhs.y + rhs.h;

        x = (x > rhs.x) ? x : rhs.x;
        y = (y > rhs.y) ? y : rhs.y;
        w = ((x1 < x2) ? x1 : x2) - x;
        h = ((y1 < y2) ? y1 : y2) - y;

        if (w < 0) w = 0;
        if (h < 0) h = 0;
    }
};

struct RenderTransform
{
    Matrix m;             //3x3 Matrix Elements
    float x = 0.0f;
    float y = 0.0f;
    float degree = 0.0f;  //rotation degree
    float scale = 1.0f;   //scale factor
    bool overriding = false;  //user transform?

    bool update();
    void override(const Matrix& m);

    RenderTransform();
    RenderTransform(const RenderTransform* lhs, const RenderTransform* rhs);
};

struct RenderStroke
{
    float width = 0.0f;
    uint8_t color[4] = {0, 0, 0, 0};
    Fill *fill = nullptr;
    float* dashPattern = nullptr;
    uint32_t dashCnt = 0;
    StrokeCap cap = StrokeCap::Square;
    StrokeJoin join = StrokeJoin::Bevel;

    ~RenderStroke()
    {
        free(dashPattern);
        if (fill) delete(fill);
    }
};

struct RenderShape
{
    struct
    {
        PathCommand* cmds = nullptr;
        uint32_t cmdCnt = 0;
        uint32_t reservedCmdCnt = 0;

        Point *pts = nullptr;
        uint32_t ptsCnt = 0;
        uint32_t reservedPtsCnt = 0;
    } path;

    Fill *fill = nullptr;
    RenderStroke *stroke = nullptr;
    uint8_t color[4] = {0, 0, 0, 0};    //r, g, b, a
    FillRule rule = FillRule::Winding;

    ~RenderShape()
    {
        free(path.cmds);
        free(path.pts);

        if (fill) delete(fill);
        if (stroke) delete(stroke);
    }

    void fillColor(uint8_t* r, uint8_t* g, uint8_t* b, uint8_t* a) const
    {
        if (r) *r = color[0];
        if (g) *g = color[1];
        if (b) *b = color[2];
        if (a) *a = color[3];
    }

    float strokeWidth() const
    {
        if (!stroke) return 0;
        return stroke->width;
    }

    bool strokeColor(uint8_t* r, uint8_t* g, uint8_t* b, uint8_t* a) const
    {
        if (!stroke) return false;

        if (r) *r = stroke->color[0];
        if (g) *g = stroke->color[1];
        if (b) *b = stroke->color[2];
        if (a) *a = stroke->color[3];

        return true;
    }

    const Fill* strokeFill() const
    {
        if (!stroke) return nullptr;
        return stroke->fill;
    }

    uint32_t strokeDash(const float** dashPattern) const
    {
        if (!stroke) return 0;
        if (dashPattern) *dashPattern = stroke->dashPattern;
        return stroke->dashCnt;
    }

    StrokeCap strokeCap() const
    {
        if (!stroke) return StrokeCap::Square;
        return stroke->cap;
    }

    StrokeJoin strokeJoin() const
    {
        if (!stroke) return StrokeJoin::Bevel;
        return stroke->join;
    }
};

class RenderMethod
{
public:
    virtual ~RenderMethod() {}
    virtual RenderData prepare(const RenderShape& rshape, RenderData data, const RenderTransform* transform, uint32_t opacity, Array<RenderData>& clips, RenderUpdateFlag flags, bool clipper) = 0;
    virtual RenderData prepare(Surface* image, Polygon* triangles, uint32_t triangleCnt, RenderData data, const RenderTransform* transform, uint32_t opacity, Array<RenderData>& clips, RenderUpdateFlag flags) = 0;
    virtual bool preRender() = 0;
    virtual bool renderShape(RenderData data) = 0;
    virtual bool renderImage(RenderData data) = 0;
    virtual bool renderImageMesh(RenderData data) = 0;
    virtual bool postRender() = 0;
    virtual bool dispose(RenderData data) = 0;
    virtual RenderRegion region(RenderData data) = 0;
    virtual RenderRegion viewport() = 0;
    virtual bool viewport(const RenderRegion& vp) = 0;

    virtual bool clear() = 0;
    virtual bool sync() = 0;

    virtual Compositor* target(const RenderRegion& region) = 0;
    virtual bool beginComposite(Compositor* cmp, CompositeMethod method, uint32_t opacity) = 0;
    virtual bool endComposite(Compositor* cmp) = 0;
};

}

#endif //_TVG_RENDER_H_