/* city.c - Don Yang (uguu.org)

   Cell type interpretation:
      bits 0-1: base size
      bits 2-3: roof type
      bits 4-7: base height
      bits 8-9: color

   05/30/03
                                                                           */

#include"global.h"
#include"city.h"


#define BuildingHeight(type)  (GLfloat)((((type) >> 4) & 15) * 0.07f + 1.4f)

/* Colors */
static const GLfloat DAmbient[4][4] =
   { {0.2f, 0.2f, 0.2f, 1.0f}, {0.2f, 0.25f, 0.2f, 1.0f},
     {0.2f, 0.2f, 0.25f, 1.0f}, {0.2f, 0.25f, 0.25f, 1.0f} };
static const GLfloat DDiffuse[4][4] =
   { {0.8f, 0.8f, 0.8f, 1.0f}, {0.7f, 1.0f, 0.7f, 1.0f},
     {0.7f, 0.7f, 1.0f, 1.0f}, {0.7f, 1.0f, 1.0f, 1.0f} };
static const GLfloat DSpecular[4] = {0.2f, 0.2f, 0.2f, 1.0f};
static const GLfloat DEmission[4] = {0.1f, 0.1f, 0.1f, 1.0f};

static const GLfloat NAmbient[4] = {0.1f, 0.1f, 0.1f, 1.0f};
static const GLfloat NDiffuse[4] = {0.6f, 0.6f, 0.6f, 1.0f};
static const GLfloat NSpecular[4] = {0.2f, 0.2f, 0.2f, 1.0f};
static const GLfloat NEmission[4] = {0.0f, 0.1f, 0.2f, 1.0f};

/* Geometry data */
static const GLfloat RoofNormalX = 1.0f, RoofNormalY = 1.3f;
static const GLfloat Edge[4] = {0.6f, 1.5f, 2.3f, 3.2f};
static const GLfloat OutlineScale[4] = {1.1f, 1.09f, 1.08f, 1.06f};
static GLfloat OutlineOffset[256];

/* Display lists */
static GLuint ObjRoofBase = 0;

/* Local functions */
static void DrawWall(GLfloat h, GLfloat e);

/********************************************************* DrawCityOutline */
void DrawCityOutline(unsigned int type)
{
   GLfloat h, e;

   glTranslatef(0.0f, OutlineOffset[type & 255], 0.0f);
   glScalef(OutlineScale[type & 3],
            OutlineScale[type & 3],
            OutlineScale[type & 3]);

   /* Wall */
   DrawWall(h = BuildingHeight(type), e = Edge[type & 3]);

   /* Floor */
   glBegin(GL_QUADS);
      glNormal3f(0.0f, -1.0f, 0.0f);
      glVertex3f(-e, 0.0f, e);
      glVertex3f(-e, 0.0f,-e);
      glVertex3f( e, 0.0f,-e);
      glVertex3f( e, 0.0f, e);
   glEnd();

   /* Roof */
   glTranslatef(0.0f, h, 0.0f);
   glCallList(ObjRoofBase + (type & 15));

} /* DrawCityOutline() */

/*********************************************************** DrawCityTileD */
void DrawCityTileD(unsigned int type)
{
   GLfloat h;

   glMaterialfv(GL_FRONT, GL_AMBIENT, DAmbient[(type >> 8) & 3]);
   glMaterialfv(GL_FRONT, GL_DIFFUSE, DDiffuse[(type >> 8) & 3]);

   /* Wall */
   DrawWall(h = BuildingHeight(type), Edge[type & 3]);

   /* Roof */
   glTranslatef(0.0f, h, 0.0f);
   glCallList(ObjRoofBase + (type & 15));

} /* DrawCityTileD() */

/*********************************************************** DrawCityTileN */
void DrawCityTileN(unsigned int type)
{
   GLfloat h;

   /* Wall */
   DrawWall(h = BuildingHeight(type), Edge[type & 3]);

   /* Roof */
   glTranslatef(0.0f, h, 0.0f);
   glCallList(ObjRoofBase + (type & 15));

} /* DrawCityTileN() */

/*********************************************************** InitCityTiles */
void InitCityTiles(void)
{
   GLfloat h, s, e;
   unsigned int i;
   int size;

   ObjRoofBase = glGenLists(16);
   for(size = 0; size < 4; size++)
   {
      h = (GLfloat)((e = Edge[size]) * RoofNormalX / RoofNormalY);

      /* Roof type 0 */
      glNewList(ObjRoofBase + size, GL_COMPILE);
         glBegin(GL_QUADS);
            glNormal3f(-RoofNormalX, RoofNormalY, 0.0f);
            glVertex3f(  -e, 0.0f, -e);
            glVertex3f(  -e, 0.0f,  e);
            glVertex3f(0.0f,    h,  e);
            glVertex3f(0.0f,    h, -e);

            glNormal3f(RoofNormalX, RoofNormalY, 0.0f);
            glVertex3f(   e, 0.0f,  e);
            glVertex3f(   e, 0.0f, -e);
            glVertex3f(0.0f,    h, -e);
            glVertex3f(0.0f,    h,  e);
         glEnd();
         glBegin(GL_TRIANGLES);
            glNormal3f(0.0f, 0.0f, 1.0f);
            glVertex3f(  -e, 0.0f,    e);
            glVertex3f(   e, 0.0f,    e);
            glVertex3f(0.0f,    h,    e);
            glNormal3f(0.0f, 0.0f,-1.0f);
            glVertex3f(   e, 0.0f,   -e);
            glVertex3f(  -e, 0.0f,   -e);
            glVertex3f(0.0f,    h,   -e);
         glEnd();
      glEndList();

      /* Roof type 1 */
      glNewList(ObjRoofBase + size + 4, GL_COMPILE);
         glBegin(GL_TRIANGLES);
            glNormal3f(-RoofNormalX, RoofNormalY, 0.0f);
            glVertex3f(0.0f,    h, 0.0f);
            glVertex3f(  -e, 0.0f,   -e);
            glVertex3f(  -e, 0.0f,    e);

            glNormal3f(0.0f, RoofNormalY, RoofNormalX);
            glVertex3f(0.0f,    h, 0.0f);
            glVertex3f(  -e, 0.0f,    e);
            glVertex3f(   e, 0.0f,    e);

            glNormal3f(RoofNormalX, RoofNormalY, 0.0f);
            glVertex3f(0.0f,    h, 0.0f);
            glVertex3f(   e, 0.0f,    e);
            glVertex3f(   e, 0.0f,   -e);

            glNormal3f(0.0f, RoofNormalY, -RoofNormalX);
            glVertex3f(0.0f,    h, 0.0f);
            glVertex3f(   e, 0.0f,   -e);
            glVertex3f(  -e, 0.0f,   -e);
         glEnd();
      glEndList();

      /* Roof type 2 (duplicate of type 0) */
      glNewList(ObjRoofBase + size + 8, GL_COMPILE);
         glCallList(ObjRoofBase + size);
      glEndList();

      /* Roof type 3 */
      glNewList(ObjRoofBase + size + 12, GL_COMPILE);
         glBegin(GL_QUADS);
            glNormal3f(0.0f, 1.0f, 0.0f);
            glVertex3f(-e, 0.0f, e);
            glVertex3f( e, 0.0f, e);
            glVertex3f( e, 0.0f,-e);
            glVertex3f(-e, 0.0f,-e);
         glEnd();
      glEndList();
   }

   /* Compute outline offsets.  This is to keep expanded
      outline geometry center-aligned with original.     */
   for(i = 0; i < 256; i++)
   {
      h = BuildingHeight(i);
      s = OutlineScale[i & 3];
      e = Edge[i & 3];
      OutlineOffset[i] = (i & 12) == 12
         ? -0.5f * (h * (s - 1.0f))
         : -0.5f * ((h + e * RoofNormalX / RoofNormalY) * (s - 1.0f));
   }

} /* InitCityTiles() */

/********************************************************** SetupCityTileD */
void SetupCityTileD(void)
{
   glShadeModel(GL_FLAT);
   glMaterialfv(GL_FRONT, GL_SPECULAR, DSpecular);
   glMaterialfv(GL_FRONT, GL_EMISSION, DEmission);

} /* SetupCityTileD() */

/********************************************************** SetupCityTileN */
void SetupCityTileN(void)
{
   glShadeModel(GL_FLAT);
   glMaterialfv(GL_FRONT, GL_AMBIENT, NAmbient);
   glMaterialfv(GL_FRONT, GL_DIFFUSE, NDiffuse);
   glMaterialfv(GL_FRONT, GL_SPECULAR, NSpecular);
   glMaterialfv(GL_FRONT, GL_EMISSION, NEmission);

} /* SetupCityTileN() */

/********************************************************* UninitCityTiles */
void UninitCityTiles(void)
{
   if( ObjRoofBase != 0 )
      glDeleteLists(ObjRoofBase, 16);

} /* UninitCityTiles() */


/*************************************************************** DrawWall */
static void DrawWall(GLfloat h, GLfloat e)
{
   glBegin(GL_QUAD_STRIP);
      glNormal3f(-1.0f, 0.0f, 0.0f);
      glVertex3f(-e,    h,-e);
      glVertex3f(-e, 0.0f,-e);
      glVertex3f(-e,    h, e);
      glVertex3f(-e, 0.0f, e);

      glNormal3f( 0.0f, 0.0f, 1.0f);
      glVertex3f( e,    h, e);
      glVertex3f( e, 0.0f, e);

      glNormal3f( 1.0f, 0.0f, 0.0f);
      glVertex3f( e,    h,-e);
      glVertex3f( e, 0.0f,-e);

      glNormal3f( 0.0f, 0.0f,-1.0f);
      glVertex3f(-e,    h,-e);
      glVertex3f(-e, 0.0f,-e);
   glEnd();

   #if 0 /* Same as above, obviously slower */
   glBegin(GL_QUADS);
      glNormal3f(-1.0f, 0.0f, 0.0f);
      glVertex3f(-e,    h, e); glVertex3f(-e,    h,-e);
      glVertex3f(-e, 0.0f,-e); glVertex3f(-e, 0.0f, e);

      glNormal3f( 0.0f, 0.0f, 1.0f);
      glVertex3f( e,    h, e); glVertex3f(-e,    h, e);
      glVertex3f(-e, 0.0f, e); glVertex3f( e, 0.0f, e);

      glNormal3f( 1.0f, 0.0f, 0.0f);
      glVertex3f( e,    h,-e); glVertex3f( e,    h, e);
      glVertex3f( e, 0.0f, e); glVertex3f( e, 0.0f,-e);

      glNormal3f( 0.0f, 0.0f,-1.0f);
      glVertex3f(-e,    h,-e); glVertex3f( e,    h,-e);
      glVertex3f( e, 0.0f,-e); glVertex3f(-e, 0.0f,-e);
   glEnd();
   #endif

} /* DrawWall() */