/**
 *
 * This file is part of Tulip (www.tulip-software.org)
 *
 * Authors: David Auber and the Tulip development Team
 * from LaBRI, University of Bordeaux
 *
 * Tulip is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation, either version 3
 * of the License, or (at your option) any later version.
 *
 * Tulip is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 */
#include <GL/glew.h>

#include <tulip/Glyph.h>
#include <tulip/GlPolygon.h>
#include <tulip/GlShaderProgram.h>
#include <tulip/GlTextureManager.h>
#include <tulip/GlGraphInputData.h>
#include <tulip/GlTools.h>
#include <tulip/TulipViewSettings.h>

using namespace tlp;
using namespace std;

namespace tlp {

const string roundedBoxFragmentShaderSrc =
  "uniform float boxWidth;"
  "uniform float boxHeight;"

  "uniform bool textureActivated;"
  "uniform sampler2D texture;"

  "void main() {"
  "	float radius = min(boxWidth / 4.0, boxHeight / 4.0);"
  "	float sRadius = radius / boxWidth;"
  "	float tRadius = radius / boxHeight;"
  "	if (gl_TexCoord[0].s < sRadius && gl_TexCoord[0].t < tRadius) {"
  "		float dist = distance(vec2(sRadius*boxWidth, tRadius*boxHeight), gl_TexCoord[0].st * vec2(boxWidth, boxHeight));"
  "		if (dist > radius)"
  "			discard;"
  "	}"
  "	if (gl_TexCoord[0].s > (1.0 - sRadius) && gl_TexCoord[0].t > (1.0 - tRadius)) {"
  "		float dist = distance(vec2((1.0 - sRadius)*boxWidth, (1.0 - tRadius)*boxHeight), gl_TexCoord[0].st * vec2(boxWidth, boxHeight));"
  "		if (dist > radius)"
  "			discard;"
  "	}"
  "	if (gl_TexCoord[0].s < sRadius && gl_TexCoord[0].t > (1.0 - tRadius)) {"
  "		float dist = distance(vec2(sRadius*boxWidth, (1.0 - tRadius)*boxHeight), gl_TexCoord[0].st * vec2(boxWidth, boxHeight));"
  "		if (dist > radius)"
  "			discard;"
  "	}"
  "	if (gl_TexCoord[0].s > (1.0 - sRadius) && gl_TexCoord[0].t < tRadius) {"
  "		float dist = distance(vec2((1.0 - sRadius)*boxWidth, tRadius*boxHeight), gl_TexCoord[0].st * vec2(boxWidth, boxHeight));"
  "		if (dist > radius)"
  "			discard;"
  "	} "
  "	gl_FragColor = gl_Color;"
  "	if (textureActivated)"
  "		gl_FragColor *= texture2D(texture, gl_TexCoord[0].st);"
  "}"
  ;

const string roundedBoxOutlineVertexShaderSrc =
  "#version 120\n"
  "void main() {"
  "	gl_Position = gl_Vertex;"
  "	gl_FrontColor = gl_Color;"
  "}"
  ;

const string roundedBoxOutlineGeometryShaderSrc =
  "#version 120\n"
  "#extension GL_EXT_geometry_shader4 : enable\n"
  "#define M_PI 3.141592653589793238462643\n"

  "uniform float boxWidth;"
  "uniform float boxHeight;"

  "const int steps = 20;"
  "const float delta = (M_PI/2.0) / float(steps);"

  "void main() {"
  "	float radius = min(boxWidth / 4.0, boxHeight / 4.0);"
  "	float radiusL = radius / boxWidth;"
  "	float radiusH = radius / boxHeight;"
  "	float wi = 1.0 - 2*radiusL;"
  "	float hi = 1.0 - 2*radiusH;"
  "	vec3 P1 = gl_PositionIn[0].xyz + vec3(radiusL, -radiusH, 0.0);"
  "	vec3 P2 = P1 + vec3(wi, 0.0, 0.0);"
  "	vec3 P3 = P2 + vec3(0.0, -hi, 0.0);"
  "	vec3 P4 = P1 + vec3(0.0, -hi, 0.0);"

  "	float w = 0.0;"
  "	float x = 0.0;"
  "	float y = 0.0;"
  "	vec3 p = vec3(0.0);"

  "	gl_FrontColor = gl_FrontColorIn[0];"
  "	for (int i = 0 ; i < steps; ++i ) {"
  "		w = delta + float(i) * delta;"
  "		x = -cos(w);"
  "		y = sin(w);"
  "		p = P1 + vec3(x, y, 0.0) * vec3(radiusL, radiusH, 0.0);"
  "		gl_Position = gl_ModelViewProjectionMatrix * vec4(p, 1.0);"
  "		EmitVertex();"
  "	}"

  "	gl_FrontColor = gl_FrontColorIn[1];"
  "	for (int i = 0 ; i < steps; ++i ) {"
  "		w = delta + float(steps - i - 1) * delta;"
  "		x = cos(w);"
  "		y = sin(w);"
  "		p = P2 + vec3(x, y, 0.0) * vec3(radiusL, radiusH, 0.0);"
  "		gl_Position = gl_ModelViewProjectionMatrix * vec4(p, 1.0);"
  "		EmitVertex();"
  "	}"

  "	gl_FrontColor = gl_FrontColorIn[2];"
  "	for (int i = 0 ; i < steps; ++i ) {"
  "		w = delta + float(i) * delta;"
  "		x = cos(w);"
  "		y = -sin(w);"
  "		p = P3 + vec3(x, y, 0.0) * vec3(radiusL, radiusH, 0.0);"
  "		gl_Position = gl_ModelViewProjectionMatrix * vec4(p, 1.0);"
  "		EmitVertex();"
  "	}"

  "	gl_FrontColor = gl_FrontColorIn[3];"
  "	for (int i = 0 ; i < steps; ++i ) {"
  "		float w = delta + float(steps - i - 1) * delta;"
  "		float x = -cos(w);"
  "		float y = -sin(w);"
  "		p = P4 + vec3(x, y, 0.0) * vec3(radiusL, radiusH, 0.0);"
  "		gl_Position = gl_ModelViewProjectionMatrix * vec4(p, 1.0);"
  "		EmitVertex();"
  "	}"

  "	w = delta;"
  "	x = -cos(w);"
  "	y = sin(w);"

  "	p = P1 + vec3(x, y, 0.0) * vec3(radiusL, radiusH, 0.0);"
  "	gl_Position = gl_ModelViewProjectionMatrix * vec4(p, 1.0);"
  "	EmitVertex();"
  "}"
  ;

/** @addtogroup glyph */

/// A 2D glyph.
/**
 * This glyph draws a rounded box, meaning a rectangle with rounded corners.
 * The box is colored according to the "viewColor" property. It can also be outlined if
 * "viewBorderWidth" is greater than zero. The outline is colored according to the
 * "viewBorderColor" property. Last but not least, it can also be textured according
 * to the "viewTexture" property.
 */

class RoundedBox : public Glyph {
public:
  GLYPHINFORMATION("2D - Rounded Box", "Antoine LAMBERT", "02/11/2010", "Rounded Box", "1.0", NodeShape::RoundedBox)
  RoundedBox(const tlp::PluginContext *context = NULL);
  ~RoundedBox() {}
  void draw(node n, float lod);
  Coord getAnchor(const Coord &vector) const;
  void getIncludeBoundingBox(BoundingBox &boundingBox, node);

private:

  void initRoundedSquare();
  GlPolygon *createRoundedRect(const Size &size);

  static GlPolygon *roundedSquare;
  static Coord minIncludeBBSquare;
  static Coord maxIncludeBBSquare;
};

static Coord computeCircleArcMidPoint(const Coord &start, const Coord &end, const Coord &center) {
  float radius = start.dist(center);
  float c=atan2(start[1]+end[1], start[0]+end[0]);
  return Coord(center.x() + radius*cos(c), center.y() + radius*sin(c));
}

GlPolygon* RoundedBox::roundedSquare=NULL;
Coord RoundedBox::minIncludeBBSquare;
Coord RoundedBox::maxIncludeBBSquare;

RoundedBox::RoundedBox(const tlp::PluginContext* context) : Glyph(context) {
  minIncludeBBSquare = computeCircleArcMidPoint(Coord(-0.25, -0.5), Coord(-0.5, -0.25), Coord(-0.25, -0.25));
  maxIncludeBBSquare = -minIncludeBBSquare;
}

void RoundedBox::initRoundedSquare() {
  roundedSquare = createRoundedRect(Size(1,1,1));
}

void RoundedBox::getIncludeBoundingBox(BoundingBox &boundingBox,node n) {
  const Size &size = glGraphInputData->getElementSize()->getNodeValue(n);

  if (size[0] == size[1]) {
    boundingBox[0] = minIncludeBBSquare;
    boundingBox[1] = maxIncludeBBSquare;
  }
  else {
    float radius = min(size[0] / 4, size[1] / 4);
    radius = min(radius/size[0], radius/size[1]);
    boundingBox[0] = computeCircleArcMidPoint(Coord(-0.5+radius, -0.5), Coord(-0.5, -0.5+radius), Coord(-0.5+radius, -0.5+radius));
    boundingBox[1] = -boundingBox[0];
  }
}

GlPolygon *RoundedBox::createRoundedRect(const Size &size) {
  float radius = min(size[0] / 4, size[1] / 4);
  float radiusL = radius / size[0];
  float radiusH = radius / size[1];

  float wi = 1.0 - 2*radiusL;
  float hi = 1.0 - 2*radiusH;

  Coord P1 = Coord(-0.5, 0.5) + Coord(radiusL, -radiusH);
  Coord P2 = P1 + Coord(wi, 0);
  Coord P3 = P2 + Coord(0, -hi);
  Coord P4 = P1 + Coord(0, -hi);

  int steps = 20;
  float delta = (M_PI/2) / steps;

  vector<Coord> boxPoints;
  boxPoints.resize(steps * 4);

#ifdef _OPENMP
  #pragma omp parallel for
#endif

  for (int i = 0 ; i < steps; ++i ) {
    float w = delta + i * delta;
    float x = -cos(w);
    float y = sin(w);
    Coord p = P1 + Coord(x, y) * Coord(radiusL, radiusH);
    boxPoints[i] = p;

    w = delta + (steps - i - 1) * delta;
    x = cos(w);
    y = sin(w);
    p = P2 + Coord(x, y) * Coord(radiusL, radiusH);
    boxPoints[steps + i] = p;

    w = delta +  i * delta;
    x = cos(w);
    y = -sin(w);
    p = P3 + Coord(x, y) * Coord(radiusL, radiusH);
    boxPoints[2 * steps + i] = p;

    w = delta + (steps - i - 1) * delta;
    x = -cos(w);
    y = -sin(w);
    p = P4 + Coord(x, y) * Coord(radiusL, radiusH);
    boxPoints[3 * steps + i] = p;
  }

  vector<Color> fillColors;
  vector<Color> outlineColors;

  fillColors.push_back(Color(255,255,255));
  outlineColors.push_back(Color(0,0,0));

  GlPolygon *ret = new GlPolygon(boxPoints, fillColors, outlineColors, true, true);
  ret->setInvertYTexture(false);

  return ret;
}

const float squareVerticesData[56] = {
  /* front face (vvttnnn) */
  -0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f,
  0.5f, -0.5f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f,
  0.5f,  0.5f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f,
  -0.5f,  0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f,

  /* back face (vvttnnn) */
  -0.5f, -0.5f, 1.0f, 0.0f, 0.0f, 0.0f, -1.0f,
  -0.5f,  0.5f, 1.0f, 1.0f, 0.0f, 0.0f, -1.0f,
  0.5f,  0.5f, 0.0f, 1.0f, 0.0f, 0.0f, -1.0f,
  0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 0.0f, -1.0f
};

const float outlineVeticesData[8] = {
  -0.5f, 0.5f,
  0.5f, 0.5f,
  0.5f, -0.5f,
  -0.5f, -0.5f
};

void RoundedBox::draw(node n, float lod) {

  static string glVendor(((const char*)glGetString(GL_VENDOR)));
  static bool glVendorOk = (glVendor.find("NVIDIA")!=string::npos) || (glVendor.find("ATI")!=string::npos);

  static GlShaderProgram *roundedBoxShader = NULL;
  static GlShaderProgram *roundedBoxOutlineShader = NULL;

  // don't use geometry shader rendering on MacOS as that feature does seem stable on that platform
  bool apple = false;
#ifdef __APPLE__
  apple = true;
#endif

  if (!apple && roundedBoxShader == NULL && glVendorOk && GlShaderProgram::shaderProgramsSupported() && GlShaderProgram::geometryShaderSupported()) {
    roundedBoxShader = new GlShaderProgram();
    roundedBoxShader->addShaderFromSourceCode(Fragment, roundedBoxFragmentShaderSrc);
    roundedBoxShader->link();
    roundedBoxShader->printInfoLog();

    roundedBoxOutlineShader = new GlShaderProgram();
    roundedBoxOutlineShader->addShaderFromSourceCode(Vertex, roundedBoxOutlineVertexShaderSrc);
    roundedBoxOutlineShader->addGeometryShaderFromSourceCode(roundedBoxOutlineGeometryShaderSrc, GL_LINES_ADJACENCY_EXT, GL_LINE_STRIP);
    roundedBoxOutlineShader->link();
    roundedBoxOutlineShader->printInfoLog();
  }

  const Size &size = glGraphInputData->getElementSize()->getNodeValue(n);

  float outlineWidth = glGraphInputData->getElementBorderWidth()->getNodeValue(n);

  const string &texture = glGraphInputData->getElementTexture()->getNodeValue(n);

  if (roundedBoxShader == NULL || !roundedBoxShader->isLinked() || !roundedBoxOutlineShader->isLinked() || GlShaderProgram::getCurrentActiveShader()) {
    if (roundedSquare == NULL)
      initRoundedSquare();

    GlPolygon *polygon = roundedSquare;

    if (size[0] != size[1]) {
      polygon = createRoundedRect(size);
    }

    polygon->setFillColor(glGraphInputData->getElementColor()->getNodeValue(n));
    polygon->setOutlineColor(glGraphInputData->getElementBorderColor()->getNodeValue(n));
    polygon->setOutlineSize(outlineWidth);
    polygon->setTextureName(texture);
    polygon->draw(lod,NULL);

    if (polygon != roundedSquare)
      // because createRoundedRect() creates a new GlPolygon
      delete polygon;
  }
  else {


    glEnableClientState(GL_VERTEX_ARRAY);
    glEnableClientState(GL_TEXTURE_COORD_ARRAY);
    glEnableClientState(GL_NORMAL_ARRAY);

    glVertexPointer(2, GL_FLOAT, 7 * sizeof(float), &squareVerticesData[0]);
    glTexCoordPointer(2, GL_FLOAT, 7 * sizeof(float), &squareVerticesData[2]);
    glNormalPointer(GL_FLOAT, 7 * sizeof(float), &squareVerticesData[4]);

    setMaterial(glGraphInputData->getElementColor()->getNodeValue(n));

    bool textureOK = false;

    if (texture != "") {
      textureOK = GlTextureManager::getInst().activateTexture(texture);
    }

    roundedBoxShader->activate();
    roundedBoxShader->setUniformFloat("boxWidth", size[0]);
    roundedBoxShader->setUniformFloat("boxHeight", size[1]);
    roundedBoxShader->setUniformBool("textureActivated", textureOK);
    roundedBoxShader->setUniformTextureSampler("texture", 0);
    glDrawArrays(GL_QUADS, 0, 8);
    roundedBoxShader->desactivate();

    if (textureOK) {
      GlTextureManager::getInst().desactivateTexture();
    }

    glDisableClientState(GL_TEXTURE_COORD_ARRAY);
    glDisableClientState(GL_NORMAL_ARRAY);

    if (outlineWidth == 0) {
      glLineWidth(1.0);
      setMaterial(glGraphInputData->getElementColor()->getNodeValue(n));
    }
    else {
      glLineWidth(outlineWidth);
      setMaterial(glGraphInputData->getElementBorderColor()->getNodeValue(n));
    }

    glVertexPointer(2, GL_FLOAT, 2 * sizeof(float), outlineVeticesData);

    roundedBoxOutlineShader->activate();
    roundedBoxOutlineShader->setUniformFloat("boxWidth", size[0]);
    roundedBoxOutlineShader->setUniformFloat("boxHeight", size[1]);
    glDrawArrays(GL_LINE_STRIP_ADJACENCY_EXT, 0, 4);
    roundedBoxOutlineShader->desactivate();

    glDisableClientState(GL_VERTEX_ARRAY);
  }
}

Coord RoundedBox::getAnchor(const Coord &vector) const {
  Coord v(vector);
  float x, y, z, fmax;
  v.get(x, y, z);
  v.setZ(0.0f);
  fmax = std::max(fabsf(x), fabsf(y));

  if (fmax > 0.0f)
    return v * (0.5f / fmax);
  else
    return v;
}

PLUGIN(RoundedBox)

} // end of namespace tlp