Reference no: EM13870997

Overview

In this assignment you will implement C code for drawing filled triangles in a window on the screen.

Description

Your task is to complete the functions listed below. Together these functions provide functionality to draw filled triangles on the screen. In addition, the functions enable you to scale the size of a triangle and move (translate) a triangle to a given position on the screen.

Each triangle is described by a triangle_t data structure. All the functions below accept a pointer to a triangle data structure as input. Each function needs to access and modify the fields of the data structure as appropriate.

• ScaleTriangle - Scale the size of the triangle. The scaling factor is specified in the scale field in the triangle data structure. The scaling factor is a floating point number. A factor less than 1.0 should decrease the size of the triangle, while a factor greater than 1.0 should increase the size.

• TranslateTriangle - Move the triangle to a specific position on the screen. The position is specified in the triangle data structure in the tx and ty fields.

• CalculateTriangleBoundingBox - Calculate the size of a rectangle that is just large enough to contain the triangle. The bx, by, bw, and bh fields of the triangle data structure should be initialized with the appropriate values.

• FillTriangle - Fill the triangle with a color. The fillcolor field in the triangle data structure specifies the fill color. There exists many different approaches for filling triangles and polygons in general. See the Resources section below for some inspiration.

• DrawTriangle - Draw a scaled, translated, and filled triangle on the screen.

In this assignment there should be no need to define functions beyond those already defined in the files we provide. We recommend starting with code to draw a wireframe version of the triangle on the screen (by use of the DrawLine function). Then, either proceed with the code to scale the triangle, or the code to move the triangle to a given position on the screen. Note that triangle scale is specified as a floating point number, while the triangle coordinates are integer variables. You will need to think about conversions between integer and floating point numbers to make the scaling function work properly. When scaling, translation, and drawing works, embark on the code for filling the triangles.

Once you have working code for drawing triangles, you can test it by drawing a colourful teapot on the screen, using a triangle-based model that we provide.

The teapot model is represented as an array of pre-initialized triangle data structures. The model is contained within a 1000x1000 box, with coordinates ranging from -500 to 500 on both the x and y axis.

To properly draw this model you must translate it to the middle of the screen. Note that in this assignment we set the resolution of the screen to 1024x768 pixels. If translated to the middle of the screen, the teapot model does not have y coordinates that exceed the resolution of the screen. Thus there is no need to scale the teapot before drawing it.

Code

Your starting point is the following set of files:

• drawline.h - Specifies the interface of the drawline function. Do not modify this file.

• drawline.c - Implements the DrawLine function.

• triangle.h - Specifies the triangle data structure and the interface to the DrawTriangle function. Do not modify this file.

• triangle.c - Empty stubs for DrawTriangle and other functions. You will be editing this file.

• teapot_data.h - Coordinates for the classic teapot model.

• main.c - Contains the main function, calls to initialize SDL, and calls to draw some example triangles.

• Makefile - A Makefile for compiling the code.

Attachment:- problem.zip