/*******************************************************************
	       Template for your Triangle Drawing Function
********************************************************************
    Author: Stan Sclaroff
  Comments: Template for your function that draws a triangle.            
            given the triangle points in the Vertex tri[3]. 
              
	    if(renderFlags == 0)
               then render triangle using only first vertex color
               (flat shading)
 
            else if(renderFlags & SMOOTH_SHADING_BIT) != 0)
	       then render triangle using smooth shading

	    else if((renderFlags & TEXTURE_MAPPING_BIT) != 0)
	       then render using texture map look up (u,v)

            Note texture mapping is only required for CS680 students.
	    Provided for CS480/CS680 programming assignment #1.

********************************************************************/

#include "types.h"
#include "funcs.h"

#define ROUND(A) ((int) ((A)+0.5))

void drawTriangle(Vertex tri[3], int renderFlags)
{
  /* Write a triangle rasterizer that uses your drawLine function
     to fill scanlines inside the triangle.  Your algorithm must
     fill _scanlines_.

     Note that in the vertex structure (defined in "types.h"):

	 x,y are the vertex positions,
	
	 color is the vertex (r,g,b) color

	 (u,v are the texture map positions)
	 you only need u and v if you implement the texture mapping 

     Hints: First sort the triangle vertices by their Y value.
            Then scan the upper half and the lower half of the 
            triangle separately.  
            Be careful of horizontal edges (empty upper or lower triangle).
  */

  /*
   The following three lines are meant as a demo to show the triangle.
   They should be removed once you write your triangle rasterizer here 
  */

  setPixel(ROUND(tri[0].x), ROUND(tri[0].y), tri[0].color);
  setPixel(ROUND(tri[1].x), ROUND(tri[1].y), tri[1].color);
  setPixel(ROUND(tri[2].x), ROUND(tri[2].y), tri[2].color);

}