COMP2301 – Assignment One – C Programming (Stopwatch)

This assignment is a pass/fail assignment. I achieved a pass.

The goal of this assignment is write C code to generate on screen graphics representing a simple analogue / digital stopwatch .

The application must have the following features:

Stopwatch face must have two hands. (Seconds, Minutes)
Stopwatch face must have a circular outline
Stopwatch face must contain a digital minutes : seconds display
Second hand must sweep behind the digital display
Code must be modular and make good use of C functions
All graphics must be generated by pixel manipulation only
Code comments must correctly reference the work of others

Compiled (WIN32) binary (189 KB)
Assignment-1.h file
Assignment-1.c file

Assignment-1.h
/* * Author: Ned Martin #40529927 * * Creation Date: 13-MAR-2004 * * Copyright: Ned Martin, Student s40529927, for COMP2301, * University of Queensland * * Description: Assignment 1 for COMP2301 * Draws a clock face, second and minute hands, and digital * display, and maintains a count of the minutes and * seconds elapsed, updating its display to match this. * * Tab Stops: Eight spaces */ /* * Defines constants used throughout */ const double PI = 3.1415926535897932384626433832795; // pi used in circle math /* * Colour constants, defining colours used in drawing the clock */ const int COLOUR_BG = 0xFFFFFF, // colour of background - this colour // must match the background of the // window canvas COLOUR_SECONDS = 0xFF, // colour of second hand COLOUR_MINUTES = 0x0, // colour of minute hand COLOUR_TICKS = 0x0, // colour of the border and time marks COLOUR_DIGIT = 0x2C3C35, // colour of the digits COLOUR_DIGIT_UNLIT = 0xA7B7A8, // colour of the unlit digits COLOUR_DIGIT_BG = 0xD0E0CF; // colour of the digital background /* * Position constants used to define positions and sizes of elements when * drawing the clock */ const int RADIUS = 100, // radius of the clock face CENTRE_X = 200, // x centre of clock face CENTRE_Y = 200, // y center of clock face MINUTE_HAND_WIDTH = 2, // width of hands SECOND_HAND_WIDTH = 1, // width of hands TICK_WIDTH = 1, // width of ticks DIGIT_WIDTH = 3, // width of digits for digital display DIGIT_SCALE = 10, // scale factor for digital display DIGIT_OFFSET_X = 150, // x offset for digital display DIGIT_OFFSET_Y = 230, // y offset for digital display DIGIT_SPACING = 10; // spacing between digits // fix compiler name mangling #ifdef __cplusplus extern "C" { #endif /* * Function: incrementTime * * Purpose: Increments a time counter. * * Method: Called from a timer, increments a second and minute counter. * * Returns: None */ void incrementTime(); /* * Function: changeTime * * Purpose: Changes the time displayed on the clock, redrawing the hands and * digital display if necessary. * * Method: Accepts a handle to the window canvas and calls various * procedures to update the minute and second hands and digital * display. * * Returns: None */ void changeTime ( HDC hdc // window canvas ); /* * Function: drawDigital * * Purpose: Draws a digital display representing time elapsed. * * Method: Accepts a handle to the window canvas and calls drawDigit with * arguments to draw a four digit digital display and blanks out * previous digits by calling drawDigit to draw an eight using the * background colour. * * Returns: None */ void drawDigital ( HDC hdc // window canvas ); /* * Function: drawHand * * Purpose: Draws second and minute hands. * * Method: Accepts a handle to the window canvas, a seconds value, length * and colour and draws a line from a specified centre value with * the given length, width and colour the given number of seconds * around a circle. * * Returns: None */ void drawHand ( HDC hdc, // window canvas int seconds, // second to draw hand at int length, // length to draw hand int width, // width to draw hand int colour // colour to draw hand ); /* * Function: drawClockFace * * Purpose: Draws a representation of an analogue clock face. * * Method: Accepts a handle to the window canvas and draws ticks in the * seconds position around a circle, with ticks in the 15 and 5 * second positions being longer. * * Returns: None */ void drawClockFace ( HDC hdc // window canvas ); /* * Function: drawCircle * * Purpose: Draws a circle. * * Method: Accepts a handle to the window canvas, centre coordinates, * radius and a colour and draws a circle with the given * dimensions. * * Returns: None */ void drawCircle ( HDC hdc, // window canvas int centreX, // x coordinate of centre of circle int centreY, // y coordinate of centre of circle int radius, // circle radius int colour // circle colour ); /* * Function: drawLine * * Purpose: Draws a straight line. * * Method: Accepts a handle to the window canvas, start and end * coordinates, a width and a colour and draws a straight line of * that width and colour from the start to the end coordinates * given. * * Returns: None * * Reference: Thanks to Matt Koczorowski for help getting my mind around the * principles of drawing a straight line at the pixel level. * (Koczorowski, Matt 2004, verbal communication, 11 March) */ void drawLine ( HDC hdc, // window canvas int startX, // start x coordinate int startY, // start y coordinate int endX, // end x coordinate int endY, // end y coordinate int lineWidth, // width of line int colour // colour of line ); /* * Function: drawSegment * * Purpose: Draws a segment of a standard digital type display. * * Method: Accepts a handle to the window canvas, segment index, position * offset and colour and draws a the correct segment at the * position given and with the given colour, using a constant scale * factor and offset to determine the segment size. * * Returns: None */ void drawSegment ( HDC hdc, // window canvas int segment, // segment to draw (1 to 7) int position, // position to draw segment int colour // colour to draw segment ); /* * Function: drawDigit * * Purpose: Draws a digital display type digit. * * Method: Accepts a handle to the window canvas, a digit, position and * colour and calls drawSegment with the appropriate segments to * draw the given digit with the given colour and in the given * position. * * Returns: None */ void drawDigit ( HDC hdc, // window canvas int digit, // digit to draw int position, // position to draw the digit int colour // colour to draw the digit ); /* * Function: fillRectangle * * Purpose: Draws a filled rectangle with a border. * * Method: Accepts a handle to the window canvas, start and end * coordinates, border colour and a fill colour and draws a * rectangle from the top left start coordinates to the bottom * right end coordinates filled with the given colour and with a * border of the given border colour. * * Returns: None */ void fillRectangle ( HDC hdc, // window canvas int startX, // x coordinate to begin rectangle int startY, // y coordinate to begin rectangle int endX, // x coordinate to end rectangle int endY, // y coordinate to end rectangle int borderColour, // colour of the border int colour // colour to draw and fill rectangle ); #ifdef __cplusplus } #endif

Assignment-1.c
/* * Author: Ned Martin #40529927 * * Creation Date: 13-MAR-2004 * * Copyright: Ned Martin, Student s40529927, for COMP2301, * University of Queensland * * Description: Assignment 1 for COMP2301 * Draws a clock face, second and minute hands, and digital * display, and maintains a count of the minutes and * seconds elapsed, updating its display to match this. * * Tab Stops: Eight spaces */ #include <math.h> // cos, sin, sqrt #include "StdAfx.h" // for 'hdc' #include "s40529927_1.h" // function prototypes, constants int gElapsedSeconds = 0, // seconds elapsed since start gElapsedMinutes = 0; // minutes elapsed since start /* * Function: incrementTime * * Purpose: Increments a time counter. * * Method: Called from a timer, increments a second and minute counter. * * Returns: None */ void incrementTime() { // increment the second counter but reset to 0 after 59 gElapsedSeconds++; gElapsedSeconds = gElapsedSeconds % 60; //every 60 seconds we need to increment minute counter if (!gElapsedSeconds) // every 60 seconds when seconds == 0 { // increment the minute counter but reset to 0 after 59 gElapsedMinutes++; gElapsedMinutes = gElapsedMinutes % 60; } } // end incrementTime /* * Function: changeTime * * Purpose: Changes the time displayed on the clock, redrawing the hands and * digital display if necessary. * * Method: Accepts a handle to the window canvas and calls various * procedures to update the minute and second hands and digital * display. * * Returns: None */ void changeTime ( HDC hdc // window canvas ) { // clear previous second hand drawHand(hdc, gElapsedSeconds - 1, RADIUS, SECOND_HAND_WIDTH, COLOUR_BG); // clear previous minute hand drawHand(hdc, gElapsedMinutes - 1, RADIUS - 15, MINUTE_HAND_WIDTH, COLOUR_BG); // draw minute hand drawHand(hdc, gElapsedMinutes, RADIUS - 15, MINUTE_HAND_WIDTH, COLOUR_MINUTES); // draw second hand drawHand(hdc, gElapsedSeconds, RADIUS, SECOND_HAND_WIDTH, COLOUR_SECONDS); // draw rectangle for digital display fillRectangle(hdc, DIGIT_OFFSET_X - 10, DIGIT_OFFSET_Y - 10, DIGIT_OFFSET_X + 5 * (DIGIT_SCALE + DIGIT_SPACING) - DIGIT_SPACING + 1 + 10, DIGIT_OFFSET_Y + 2 * DIGIT_SCALE + 1 + 10, COLOUR_TICKS, COLOUR_DIGIT_BG); // draw digital display drawDigital(hdc); } // end changeTime /* * Function: drawDigital * * Purpose: Draws a digital display representing time elapsed. * * Method: Accepts a handle to the window canvas and calls drawDigit with * arguments to draw a four digit digital display and blanks out * previous digits by calling drawDigit to draw an eight using the * background colour. * * Returns: None */ void drawDigital ( HDC hdc // window canvas ) { // holds tens value of gElapsedSeconds int secondTens = gElapsedSeconds / 10; // holds ones value of gElapsedSeconds int secondOnes = gElapsedSeconds - (10 * secondTens); // holds tens value of gElapsedMinutes int minuteTens = gElapsedMinutes / 10; // holds ones value of gElapsedMinutes int minuteOnes = gElapsedMinutes - (10 * minuteTens); // draw tens minute digit, overwriting old digit first drawDigit(hdc, 8, 0, COLOUR_DIGIT_UNLIT); drawDigit(hdc, minuteTens, 0, COLOUR_DIGIT); // draw ones minute digit, overwriting old digit first drawDigit(hdc, 8, 1, COLOUR_DIGIT_UNLIT); drawDigit(hdc, minuteOnes, 1, COLOUR_DIGIT); // draw tens second digit, overwriting old digit first drawDigit(hdc, 8, 3, COLOUR_DIGIT_UNLIT); drawDigit(hdc, secondTens, 3, COLOUR_DIGIT); // draw ones second digit, overwriting old digit first drawDigit(hdc, 8, 4, COLOUR_DIGIT_UNLIT); drawDigit(hdc, secondOnes, 4, COLOUR_DIGIT); } // end drawDigital /* * Function: drawHand * * Purpose: Draws second and minute hands. * * Method: Accepts a handle to the window canvas, a seconds value, length * and colour and draws a line from a specified centre value with * the given length, width and colour the given number of seconds * around a circle. * * Returns: None */ void drawHand ( HDC hdc, // window canvas int seconds, // second to draw hand at int length, // length to draw hand int width, // width to draw hand int colour // colour to draw hand ) { // calculate coordinates for hand around a circle int xx = (int) (length * cos(PI * (seconds - 15) / 30)); int yy = (int) (length * sin(PI * (seconds - 15) / 30)); // draw hand drawLine(hdc, CENTRE_X, CENTRE_Y, xx + CENTRE_X, yy + CENTRE_Y, width, colour); } // end drawHand /* * Function: drawClockFace * * Purpose: Draws a representation of an analogue clock face. * * Method: Accepts a handle to the window canvas and draws ticks in the * seconds position around a circle, with ticks in the 15 and 5 * second positions being longer. * * Returns: None */ void drawClockFace ( HDC hdc // window canvas ) { // Draw the clock face int startX, // start x coordinate startY, // start y coordinate endX, // end x coordinate endY, // end y coordinate tickSpace = 10, // space between end of hands and start // of ticks tickLength = 10, // length to draw clock face ticks ii; // counter variable // loop through 60 ii to draw clockface for (ii = 0; ii < 60; ii++) // 60 seconds around the clockface { if (!(ii % 15)) // a 15 second division { tickLength = 20; } else if (!(ii % 5)) // a 5 second division { tickLength = 15; } // else set ticklength for small ticks else tickLength = 10; // set start positions for ticks startX = (int) ((RADIUS + tickSpace) * sin(PI * ii/30)); startY = (int) ((RADIUS + tickSpace) * cos(PI * ii/30)); // set end positions for ticks endX = (int) ((RADIUS + tickSpace + tickLength) * sin(PI * ii/30)); endY = (int) ((RADIUS + tickSpace + tickLength) * cos(PI * ii/30)); // draw the ticks drawLine(hdc, startX + CENTRE_X, startY + CENTRE_Y, endX + CENTRE_X, endY + CENTRE_Y, TICK_WIDTH, COLOUR_TICKS); } // draw clock face circle drawCircle(hdc, CENTRE_X, CENTRE_Y, RADIUS + tickSpace + 20, COLOUR_TICKS); } // end drawClockFace /* * Function: drawCircle * * Purpose: Draws a circle. * * Method: Accepts a handle to the window canvas, centre coordinates, * radius and a colour and draws a circle with the given * dimensions. * * Returns: None */ void drawCircle ( HDC hdc, // window canvas int centreX, // x coordinate of centre of circle int centreY, // y coordinate of centre of circle int radius, // circle radius int colour // circle colour ) { int x = 1, // x coordinate y, // y coordinate r2 = radius * radius; // radius squared // patch holes SetPixel(hdc, centreX, centreY - radius, colour); // top SetPixel(hdc, centreX - radius, centreY, colour); // left SetPixel(hdc, centreX, centreY + radius, colour); // bottom SetPixel(hdc, centreX + radius, centreY, colour); // right y = (int)(sqrt(r2 - 1) + 0.5); while (x < y) // draw individual octants { SetPixel(hdc, centreX + x, centreY - y, colour); // 1 SetPixel(hdc, centreX + y, centreY - x, colour); // 2 SetPixel(hdc, centreX + y, centreY + x, colour); // 3 SetPixel(hdc, centreX + x, centreY + y, colour); // 4 SetPixel(hdc, centreX - x, centreY + y, colour); // 5 SetPixel(hdc, centreX - y, centreY + x, colour); // 6 SetPixel(hdc, centreX - y, centreY - x, colour); // 7 SetPixel(hdc, centreX - x, centreY - y, colour); // 8 x += 1; y = (int)(sqrt(r2 - x * x) + 0.5); } if (x == y) // patch holes in quadrants { SetPixel(hdc, centreX + x, centreY - y, colour); // 1 SetPixel(hdc, centreX + x, centreY + y, colour); // 2 SetPixel(hdc, centreX - x, centreY + y, colour); // 3 SetPixel(hdc, centreX - x, centreY - y, colour); // 4 } } // end drawCircle /* * Function: drawLine * * Purpose: Draws a straight line. * * Method: Accepts a handle to the window canvas, start and end * coordinates, a width and a colour and draws a straight line of * that width and colour from the start to the end coordinates * given. * * Returns: None * * Reference: Thanks to Matt Koczorowski for help getting my mind around the * principles of drawing a straight line at the pixel level. * (Koczorowski, Matt 2004, verbal communication, 11 March) */ void drawLine ( HDC hdc, // window canvas int startX, // start x coordinate int startY, // start y coordinate int endX, // end x coordinate int endY, // end y coordinate int lineWidth, // width of line int colour // colour of line ) { double x = startX, // x coordinate y = startY; // y coordinate int ii, jj, kk, // loop variables width = (endX - startX), // width of rect enclosing line height = (endY - startY), // height of rect enclosing line largest; // largest of height or width // set largest to the larger of the absolute values of height or width if(abs(width) > abs(height)) { largest = abs(width); } else largest = abs(height); for (ii = 0; ii < largest; ii++) // all pixels required in line { x += (((double)width)/((double)largest)); y += (((double)height)/((double)largest)); // increase the x and y position by the x and y step required // (one of these will be 1, one of these will be < 1) for (jj = 0; jj < lineWidth ; jj++) // width of line { //draw each pixel in the line, adjusting for size // purposes for (kk = 0; kk < lineWidth; kk++ ) // each pixel { SetPixel (hdc, (int)(x + jj), (int)(y + kk), colour); SetPixel (hdc, (int)(x - jj), (int)(y - kk), colour); } } } } // end drawLine /* * Function: drawSegment * * Purpose: Draws a segment of a standard digital type display. * * Method: Accepts a handle to the window canvas, segment index, position * offset and colour and draws a the correct segment at the * position given and with the given colour, using a constant scale * factor and offset to determine the segment size. * * Returns: None */ void drawSegment ( HDC hdc, // window canvas int segment, // segment to draw (1 to 7) int position, // position to draw segment int colour // colour to draw segment ) { char* coords; // array to hold coordinates int x1, // start x coordinate y1, // start y coordinate x2, // end x coordinate y2; // end y coordinate /* Make a character array to define start and end points of segments, in format coords[start x, start y, end x, end y] 0 1 0 ------ | | | | 1 ------ | | | | 2 ------ */ switch(segment) { case 1: coords = "0001"; break; case 2: coords = "0010"; break; case 3: coords = "1011"; break; case 4: coords = "0111"; break; case 5: coords = "0102"; break; case 6: coords = "1112"; break; case 7: coords = "0212"; break; } // get the the x and y values from the array, subtracting 48 because // they're ASCII x1 = (int)(coords[0] - 48); // start x coordinate y1 = (int)(coords[1] - 48); // start y coordinate x2 = (int)(coords[2] - 48); // end x coordinate y2 = (int)(coords[3] - 48); // end y coordinate // position offset position = position * (DIGIT_SCALE + DIGIT_SPACING); // scale segments x1 = x1 * DIGIT_SCALE + position; y1 = y1 * DIGIT_SCALE; x2 = x2 * DIGIT_SCALE + position; y2 = y2 * DIGIT_SCALE; // draw the line drawLine(hdc, x1 + DIGIT_OFFSET_X, y1 + DIGIT_OFFSET_Y, x2 + DIGIT_OFFSET_X, y2 + DIGIT_OFFSET_Y, DIGIT_WIDTH, colour); } // end drawSegment /* * Function: drawDigit * * Purpose: Draws a digital display type digit. * * Method: Accepts a handle to the window canvas, a digit, position and * colour and calls drawSegment with the appropriate segments to * draw the given digit with the given colour and in the given * position. * * Returns: None */ void drawDigit ( HDC hdc, // window canvas int digit, // digit to draw int position, // position to draw the digit int colour // colour to draw the digit ) { char* segments; // array to hold segment flags int segment, // number of segment to draw ii; // generic counter /* Make a character array to hold segments needed for specific digits, where segments are numbered as below: 2 ------ 1 | | 3 | 4 | ------ 5 | | 6 | | ------ 7 */ switch(digit) { case 1: segments = "3600000"; break; case 2: segments = "2345700"; break; case 3: segments = "2346700"; break; case 4: segments = "1436000"; break; case 5: segments = "2146700"; break; case 6: segments = "2146750"; break; case 7: segments = "2360000"; break; case 8: segments = "1234567"; break; case 9: segments = "1234670"; break; case 0: segments = "1236750"; break; default : break; } // get the values of segments to draw from the array, subtracting 48 // because they're ASCII and then draw segments for(ii = 0; ii < 7; ii++) { segment = (int)(segments[ii] - 48); if(segment != 0) { drawSegment(hdc, segment, position, colour); } } } // end drawDigit /* * Function: fillRectangle * * Purpose: Draws a filled rectangle with a border. * * Method: Accepts a handle to the window canvas, start and end * coordinates, border colour and a fill colour and draws a * rectangle from the top left start coordinates to the bottom * right end coordinates filled with the given colour and with a * border of the given border colour. * * Returns: None */ void fillRectangle ( HDC hdc, // window canvas int startX, // x coordinate to begin rectangle int startY, // y coordinate to begin rectangle int endX, // x coordinate to end rectangle int endY, // y coordinate to end rectangle int borderColour, // colour of the border int colour // colour to draw and fill rectangle ) { int ii; for(ii = startY + 1; ii < endY; ii++) // all y { drawLine(hdc, startX, ii, endX, ii, 1, colour); } // draw border drawLine(hdc, startX, startY, endX, startY, 1, borderColour); // top drawLine(hdc, endX, startY, endX, endY, 1, borderColour); // right drawLine(hdc, startX, endY, endX, endY, 1, borderColour); // bottom drawLine(hdc, startX, startY, startX, endY, 1, borderColour); // left } // end fillRectangle
Code © Copyright 2004 Ned Martin

16-Mar-2004

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COMP2301 – Assignment One – C Programming (Stopwatch)