/*
    SPDX-FileCopyrightText: 2011-2013 Collabora Ltd. <info@collabora.com>
    SPDX-FileCopyrightText: 2013 Digia Plc and /or its subsidiary(-ies).
    SPDX-FileCopyrightText: 2013 basysKom GmbH <info@basyskom.com>

    SPDX-License-Identifier: LGPL-2.1-only
*/

#include "videomaterial.h"

#include <qmath.h>
#include <QOpenGLContext>
#include <QtQuick/QSGMaterialShader>

static const char * const qtvideosink_glsl_vertexShader =
    "uniform highp mat4 qt_Matrix;                      \n"
    "attribute highp vec4 qt_VertexPosition;            \n"
    "attribute highp vec2 qt_VertexTexCoord;            \n"
    "varying highp vec2 qt_TexCoord;                    \n"
    "void main() {                                      \n"
    "    qt_TexCoord = qt_VertexTexCoord;               \n"
    "    gl_Position = qt_Matrix * qt_VertexPosition;   \n"
    "}";

inline const char * const qtvideosink_glsl_bgrxFragmentShader()
{
    return
    "uniform sampler2D rgbTexture;\n"
    "uniform lowp float opacity;\n"
    "uniform mediump mat4 colorMatrix;\n"
    "varying highp vec2 qt_TexCoord;\n"
    "void main(void)\n"
    "{\n"
    "    highp vec4 color = vec4(texture2D(rgbTexture, qt_TexCoord.st).bgr, 1.0);\n"
    "    gl_FragColor = colorMatrix * color * opacity;\n"
    "}\n";
}

inline const char * const qtvideosink_glsl_xrgbFragmentShader()
{
    return
    "uniform sampler2D rgbTexture;\n"
    "uniform lowp float opacity;\n"
    "uniform mediump mat4 colorMatrix;\n"
    "varying highp vec2 qt_TexCoord;\n"
    "void main(void)\n"
    "{\n"
    "    highp vec4 color = vec4(texture2D(rgbTexture, qt_TexCoord.st).gba, 1.0);\n"
    "    gl_FragColor = colorMatrix * color * opacity;\n"
    "}\n";
}

inline const char * const qtvideosink_glsl_rgbxFragmentShader()
{
    return
    "uniform sampler2D rgbTexture;\n"
    "uniform lowp float opacity;\n"
    "uniform mediump mat4 colorMatrix;\n"
    "varying highp vec2 qt_TexCoord;\n"
    "void main(void)\n"
    "{\n"
    "    highp vec4 color = vec4(texture2D(rgbTexture, qt_TexCoord.st).rgb, 1.0);\n"
    "    gl_FragColor = colorMatrix * color * opacity;\n"
    "}\n";
}

inline const char * const qtvideosink_glsl_yuvPlanarFragmentShader()
{
    return
    "uniform sampler2D yTexture;\n"
    "uniform sampler2D uTexture;\n"
    "uniform sampler2D vTexture;\n"
    "uniform mediump mat4 colorMatrix;\n"
    "uniform lowp float opacity;\n"
    "varying highp vec2 qt_TexCoord;\n"
    "void main(void)\n"
    "{\n"
    "    highp vec4 color = vec4(\n"
    "           texture2D(yTexture, qt_TexCoord.st).r,\n"
    "           texture2D(uTexture, qt_TexCoord.st).r,\n"
    "           texture2D(vTexture, qt_TexCoord.st).r,\n"
    "           1.0);\n"
    "    gl_FragColor = colorMatrix * color * opacity;\n"
    "}\n";
}

class VideoMaterialShader : public QSGMaterialShader
{
public:
    virtual void updateState(const RenderState &state,
        QSGMaterial *newMaterial, QSGMaterial *oldMaterial)
    {
        Q_UNUSED(oldMaterial);

        VideoMaterial *material = static_cast<VideoMaterial *>(newMaterial);
        if (m_id_rgbTexture > 0) {
            program()->setUniformValue(m_id_rgbTexture, 0);
        } else {
            program()->setUniformValue(m_id_yTexture, 0);
            program()->setUniformValue(m_id_uTexture, 1);
            program()->setUniformValue(m_id_vTexture, 2);
        }

        if (state.isOpacityDirty()) {
            material->setFlag(QSGMaterial::Blending,
                qFuzzyCompare(state.opacity(), 1.0f) ? false : true);
            program()->setUniformValue(m_id_opacity, GLfloat(state.opacity()));
        }

        if (state.isMatrixDirty())
            program()->setUniformValue(m_id_matrix, state.combinedMatrix());

        program()->setUniformValue(m_id_colorMatrix, material->m_colorMatrix);

        material->bind();
    }

    virtual char const *const *attributeNames() const {
        static const char *names[] = {
            "qt_VertexPosition",
            "qt_VertexTexCoord",
            0
        };
        return names;
    }

protected:
    virtual void initialize() {
        m_id_matrix = program()->uniformLocation("qt_Matrix");
        m_id_rgbTexture = program()->uniformLocation("rgbTexture");
        m_id_yTexture = program()->uniformLocation("yTexture");
        m_id_uTexture = program()->uniformLocation("uTexture");
        m_id_vTexture = program()->uniformLocation("vTexture");
        m_id_colorMatrix = program()->uniformLocation("colorMatrix");
        m_id_opacity = program()->uniformLocation("opacity");
    }

    virtual const char *vertexShader() const {
        return qtvideosink_glsl_vertexShader;
    }

    int m_id_matrix;
    int m_id_rgbTexture;
    int m_id_yTexture;
    int m_id_uTexture;
    int m_id_vTexture;
    int m_id_colorMatrix;
    int m_id_opacity;
};

template <const char * const (*FragmentShader)()>
class VideoMaterialShaderImpl : public VideoMaterialShader
{
protected:
    virtual const char *fragmentShader() const {
        return FragmentShader();
    }
};

template <const char * const (*FragmentShader)()>
class VideoMaterialImpl : public VideoMaterial
{
public:
    virtual QSGMaterialType *type() const {
        static QSGMaterialType theType;
        return &theType;
    }

    virtual QSGMaterialShader *createShader() const {
        return new VideoMaterialShaderImpl<FragmentShader>;
    }
};

VideoMaterial *VideoMaterial::create(const BufferFormat & format)
{
    VideoMaterial *material = NULL;

    switch (format.videoFormat()) {
    // BGRx
    case GST_VIDEO_FORMAT_BGRx:
    case GST_VIDEO_FORMAT_BGRA:
        material = new VideoMaterialImpl<qtvideosink_glsl_bgrxFragmentShader>;
        material->initRgbTextureInfo(GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE, format.frameSize());
        break;
    case GST_VIDEO_FORMAT_BGR:
        material = new VideoMaterialImpl<qtvideosink_glsl_bgrxFragmentShader>;
        material->initRgbTextureInfo(GL_RGB, GL_RGB, GL_UNSIGNED_BYTE, format.frameSize());
        break;

    // xRGB
    case GST_VIDEO_FORMAT_xRGB:
    case GST_VIDEO_FORMAT_ARGB:
    case GST_VIDEO_FORMAT_AYUV:
        material = new VideoMaterialImpl<qtvideosink_glsl_xrgbFragmentShader>;
        material->initRgbTextureInfo(GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE, format.frameSize());
        break;

    // RGBx
    case GST_VIDEO_FORMAT_RGB:
    case GST_VIDEO_FORMAT_v308:
        material = new VideoMaterialImpl<qtvideosink_glsl_rgbxFragmentShader>;
        material->initRgbTextureInfo(GL_RGB, GL_RGB, GL_UNSIGNED_BYTE, format.frameSize());
        break;
    case GST_VIDEO_FORMAT_RGB16:
        material = new VideoMaterialImpl<qtvideosink_glsl_rgbxFragmentShader>;
        material->initRgbTextureInfo(GL_RGB, GL_RGB, GL_UNSIGNED_SHORT_5_6_5, format.frameSize());
        break;

    // YUV 420 planar
    case GST_VIDEO_FORMAT_I420:
    case GST_VIDEO_FORMAT_YV12:
        material = new VideoMaterialImpl<qtvideosink_glsl_yuvPlanarFragmentShader>;
        material->initYuv420PTextureInfo(
            (format.videoFormat() == GST_VIDEO_FORMAT_YV12) /* uvSwapped */,
            format.frameSize());
        break;

    default:
        Q_ASSERT(false);
        break;
    }

    material->init(format.colorMatrix());
    return material;
}

VideoMaterial::VideoMaterial() :
    m_frame(0),
    m_textureCount(0),
    m_textureFormat(0),
    m_textureInternalFormat(0),
    m_textureType(0),
    m_colorMatrixType(GST_VIDEO_COLOR_MATRIX_UNKNOWN)
{
    memset(m_textureIds, 0, sizeof(m_textureIds));
    setFlag(Blending, false);
}

VideoMaterial::~VideoMaterial()
{
    if (!m_textureSize.isEmpty())
        glDeleteTextures(m_textureCount, m_textureIds);
    gst_buffer_replace(&m_frame, NULL);
}

int VideoMaterial::compare(const QSGMaterial *other) const
{
    const VideoMaterial *m = static_cast<const VideoMaterial *>(other);
    int d = m_textureIds[0] - m->m_textureIds[0];
    if (d || m_textureCount == 1)
        return d;
    else if ((d = m_textureIds[1] - m->m_textureIds[1]) != 0)
        return d;
    else
        return m_textureIds[2] - m->m_textureIds[2];
}

void VideoMaterial::initRgbTextureInfo(
        GLenum internalFormat, GLuint format, GLenum type, const QSize &size)
{
#ifndef QT_OPENGL_ES
    //make sure we get 8 bits per component, at least on the desktop GL where we can
    switch(internalFormat) {
    case GL_RGBA:
        internalFormat = GL_RGBA8;
        break;
    case GL_RGB:
        internalFormat = GL_RGB8;
        break;
    default:
        break;
    }
#endif

    m_textureInternalFormat = internalFormat;
    m_textureFormat = format;
    m_textureType = type;
    m_textureCount = 1;
    m_textureWidths[0] = size.width();
    m_textureHeights[0] = size.height();
    m_textureOffsets[0] = 0;
}

void VideoMaterial::initYuv420PTextureInfo(bool uvSwapped, const QSize &size)
{
    int bytesPerLine = (size.width() + 3) & ~3;
    int bytesPerLine2 = (size.width() / 2 + 3) & ~3;

    m_textureInternalFormat = GL_LUMINANCE;
    m_textureFormat = GL_LUMINANCE;
    m_textureType = GL_UNSIGNED_BYTE;
    m_textureCount = 3;
    m_textureWidths[0] = bytesPerLine;
    m_textureHeights[0] = size.height();
    m_textureOffsets[0] = 0;
    m_textureWidths[1] = bytesPerLine2;
    m_textureHeights[1] = size.height() / 2;
    m_textureOffsets[1] = bytesPerLine * size.height();
    m_textureWidths[2] = bytesPerLine2;
    m_textureHeights[2] = size.height() / 2;
    m_textureOffsets[2] = bytesPerLine * size.height() + bytesPerLine2 * size.height()/2;

    if (uvSwapped)
      qSwap (m_textureOffsets[1], m_textureOffsets[2]);
}

void VideoMaterial::init(GstVideoColorMatrix colorMatrixType)
{
    initializeOpenGLFunctions();
    glGenTextures(m_textureCount, m_textureIds);
    m_colorMatrixType = colorMatrixType;
    updateColors(0, 0, 0, 0);
}

void VideoMaterial::setCurrentFrame(GstBuffer *buffer)
{
    QMutexLocker lock(&m_frameMutex);
    gst_buffer_replace(&m_frame, buffer);
}

void VideoMaterial::updateColors(int brightness, int contrast, int hue, int saturation)
{
    const qreal b = brightness / 200.0;
    const qreal c = contrast / 100.0 + 1.0;
    const qreal h = hue / 100.0;
    const qreal s = saturation / 100.0 + 1.0;

    const qreal cosH = qCos(M_PI * h);
    const qreal sinH = qSin(M_PI * h);

    const qreal h11 =  0.787 * cosH - 0.213 * sinH + 0.213;
    const qreal h21 = -0.213 * cosH + 0.143 * sinH + 0.213;
    const qreal h31 = -0.213 * cosH - 0.787 * sinH + 0.213;

    const qreal h12 = -0.715 * cosH - 0.715 * sinH + 0.715;
    const qreal h22 =  0.285 * cosH + 0.140 * sinH + 0.715;
    const qreal h32 = -0.715 * cosH + 0.715 * sinH + 0.715;

    const qreal h13 = -0.072 * cosH + 0.928 * sinH + 0.072;
    const qreal h23 = -0.072 * cosH - 0.283 * sinH + 0.072;
    const qreal h33 =  0.928 * cosH + 0.072 * sinH + 0.072;

    const qreal sr = (1.0 - s) * 0.3086;
    const qreal sg = (1.0 - s) * 0.6094;
    const qreal sb = (1.0 - s) * 0.0820;

    const qreal sr_s = sr + s;
    const qreal sg_s = sg + s;
    const qreal sb_s = sr + s;

    const float m4 = (s + sr + sg + sb) * (0.5 - 0.5 * c + b);

    m_colorMatrix(0, 0) = c * (sr_s * h11 + sg * h21 + sb * h31);
    m_colorMatrix(0, 1) = c * (sr_s * h12 + sg * h22 + sb * h32);
    m_colorMatrix(0, 2) = c * (sr_s * h13 + sg * h23 + sb * h33);
    m_colorMatrix(0, 3) = m4;

    m_colorMatrix(1, 0) = c * (sr * h11 + sg_s * h21 + sb * h31);
    m_colorMatrix(1, 1) = c * (sr * h12 + sg_s * h22 + sb * h32);
    m_colorMatrix(1, 2) = c * (sr * h13 + sg_s * h23 + sb * h33);
    m_colorMatrix(1, 3) = m4;

    m_colorMatrix(2, 0) = c * (sr * h11 + sg * h21 + sb_s * h31);
    m_colorMatrix(2, 1) = c * (sr * h12 + sg * h22 + sb_s * h32);
    m_colorMatrix(2, 2) = c * (sr * h13 + sg * h23 + sb_s * h33);
    m_colorMatrix(2, 3) = m4;

    m_colorMatrix(3, 0) = 0.0;
    m_colorMatrix(3, 1) = 0.0;
    m_colorMatrix(3, 2) = 0.0;
    m_colorMatrix(3, 3) = 1.0;

    switch (m_colorMatrixType) {
    case GST_VIDEO_COLOR_MATRIX_BT709:
        // With some webcams I see the matrix type falling here, I'm not sure
        // if it's a problem with the driver but it seems to happen on some
        // hardware.
//         m_colorMatrix *= QMatrix4x4(
//                     1.164,  0.000,  1.793, -0.5727,
//                     1.164, -0.534, -0.213,  0.3007,
//                     1.164,  2.115,  0.000, -1.1302,
//                     0.0,    0.000,  0.000,  1.0000);
//         break;
    case GST_VIDEO_COLOR_MATRIX_BT601:
        m_colorMatrix *= QMatrix4x4(
                    1.164,  0.000,  1.596, -0.8708,
                    1.164, -0.392, -0.813,  0.5296,
                    1.164,  2.017,  0.000, -1.081,
                    0.0,    0.000,  0.000,  1.0000);
        break;
    default:
        break;
    }
}

void VideoMaterial::bind()
{
    GstBuffer *frame = NULL;

    m_frameMutex.lock();
    if (m_frame)
      frame = gst_buffer_ref(m_frame);
    m_frameMutex.unlock();

    if (frame) {
        GstMapInfo info;
        gst_buffer_map(frame, &info, GST_MAP_READ);
        glActiveTexture(GL_TEXTURE1);
        bindTexture(1, info.data);
        glActiveTexture(GL_TEXTURE2);
        bindTexture(2, info.data);
        glActiveTexture(GL_TEXTURE0); // Finish with 0 as default texture unit
        bindTexture(0, info.data);
        gst_buffer_unmap(frame, &info);
        gst_buffer_unref(frame);
    } else {
        glActiveTexture(GL_TEXTURE1);
        glBindTexture(GL_TEXTURE_2D, m_textureIds[1]);
        glActiveTexture(GL_TEXTURE2);
        glBindTexture(GL_TEXTURE_2D, m_textureIds[2]);
        glActiveTexture(GL_TEXTURE0); // Finish with 0 as default texture unit
        glBindTexture(GL_TEXTURE_2D, m_textureIds[0]);
    }
}

void VideoMaterial::bindTexture(int i, const quint8 *data)
{
    glBindTexture(GL_TEXTURE_2D, m_textureIds[i]);
    glTexImage2D(
        GL_TEXTURE_2D,
        0,
        m_textureInternalFormat,
        m_textureWidths[i],
        m_textureHeights[i],
        0,
        m_textureFormat,
        m_textureType,
        data + m_textureOffsets[i]);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
}

