bmp.zip_bmp

#include <algorithm> #include <iostream> #include <fstream> #include <cmath> #include "bmp.h" using std::ofstream; using std::sort; using std::cout; using std::endl; using std::swap; using std::ios; // ---------------------------------------------------------------- // Local Function Prototypes // ---------------------------------------------------------------- static void doWrite(ofstream &out, int value); static void doWrite(ofstream &out, short value); static void doWrite(ofstream &out, const Color &theColor); // ---------------------------------------------------------------- // Class: Bmp // ---------------------------------------------------------------- Bmp::Bmp(int width, int height) : mWidth(width), mHeight(height) { // Initialize the entire bitmap to the default color (white) for(int i = 0; i < mHeight; i ++) { ColorRow row; for(int j = 0; j < mWidth; j ++) row.push_back(Color()); mImage.push_back(row); } } // ---------------------------------------------------------------- // Draw a pixel at (x, y) with color: (red, green, blue) // ---------------------------------------------------------------- void Bmp::setPixel( int x, int y, unsigned char red, unsigned char green, unsigned char blue ) { bool doSet = true; if(x < 0 || x >= mWidth) { cout << "Invalid value: " << x << " (expected: 0 <= x < " << mWidth << ")" << endl; doSet = false; } if(y < 0 || y >= mHeight) { cout << "Invalid value: " << y << " (expected: 0 <= y < " << mHeight << ")" << endl; doSet = false; } if(doSet) mImage[y][x] = Color(red, green, blue); } // ---------------------------------------------------------------- // Draw a pixel at (x, y) with color: theColor // ---------------------------------------------------------------- void Bmp::setPixel( int x, int y, const Color &theColor ) { setPixel(x, y, theColor.mRed, theColor.mGreen, theColor.mBlue); } // ---------------------------------------------------------------- // Draw a rectangle at (x, y) with the specified width and // height using color: (red, green, blue) // ---------------------------------------------------------------- void Bmp::drawRectangle( int x, int y, int width, int height, unsigned char red, unsigned char green, unsigned char blue ) { drawLine(x, y, x + width, y, red, green, blue); drawLine(x + width, y, x + width, y + height, red, green, blue); drawLine(x + width, y + height, x, y + height, red, green, blue); drawLine(x, y + height, x, y, red, green, blue); } // ---------------------------------------------------------------- // Draw a rectangle at (x, y) with the specified width and // height using color: theColor // ---------------------------------------------------------------- void Bmp::drawRectangle( int x, int y, int width, int height, const Color &theColor ) { drawRectangle( x, y, width, height, theColor.mRed, theColor.mGreen, theColor.mBlue ); } // ---------------------------------------------------------------- // Fill a rectangle at (x, y) with the specified width and // height using color: (red, green, blue) // ---------------------------------------------------------------- void Bmp::fillRectangle( int x, int y, int width, int height, unsigned char red, unsigned char green, unsigned char blue ) { for(int i = 0; i < width; i ++) { drawLine( x + i, y, x + i, y + height, red, green, blue ); } } // ---------------------------------------------------------------- // Fill a rectangle at (x, y) with the specified width and // height using color: theColor // ---------------------------------------------------------------- void Bmp::fillRectangle( int x, int y, int width, int height, const Color &theColor ) { fillRectangle( x, y, width, height, theColor.mRed, theColor.mGreen, theColor.mBlue ); } // ---------------------------------------------------------------- // Fill a polygon using color: (red, green, blue), // expects 'points' to contain an even number of values // ---------------------------------------------------------------- void Bmp::fillPolygon( const vector<int> &points, unsigned char red, unsigned char green, unsigned char blue ) { int xMin = 0; int yMin = 0; int xMax = 0; int yMax = 0; for(int i = 0, n = points.size(); i < n; i += 2) { int x = points[i]; int y = points[i + 1]; if(i == 0) { xMin = xMax = x; yMin = yMax = y; } else { if(x < xMin) xMin = x; else if(x > xMax) xMax = x; if(y < yMin) yMin = y; else if(y > yMax) yMax = y; } } typedef vector<int> YValues; typedef vector<YValues> Buffer; int width = (xMax - xMin) + 1; Buffer theBuffer; for(int i = 0; i < width; i ++) theBuffer.push_back(YValues()); for(int i = 2, n = points.size(); i < n; i += 2) { int x0 = points[i - 2]; int y0 = points[i - 1]; int x1 = points[i]; int y1 = points[i + 1]; if(x0 == x1) { theBuffer[x0 - xMin].push_back(y0); theBuffer[x0 - xMin].push_back(y1); } else { double delta = (y1 - y0) / (double)(x1 - x0); int start = 0; int stop = 0; double y = 0.0; if(x0 < x1) { y = y0; start = x0; stop = x1; } else { y = y1; start = x1; stop = x0; } for(int j = start; j < stop; j ++) { int yValue = (int)(y + 0.5); theBuffer[j - xMin].push_back(yValue); y += delta; } } } for(int i = 0, n = theBuffer.size(); i < n; i ++) sort(theBuffer[i].begin(), theBuffer[i].end()); for(int i = 0, n = theBuffer.size(); i < n; i ++) { for(int j = 1, nn = theBuffer[i].size(); j < nn; j += 2) { drawLine( xMin + i, theBuffer[i][j], xMin + i, theBuffer[i][j - 1], red, green, blue ); } } } // ---------------------------------------------------------------- // Fill a polygon using color: theColor // ---------------------------------------------------------------- void Bmp::fillPolygon(const vector<int> &points, const Color &theColor) { fillPolygon(points, theColor.mRed, theColor.mGreen, theColor.mBlue); } // ---------------------------------------------------------------- // Draw a line from (x0, y0) to (x1, y1) using // color: (red, green, blue) // ---------------------------------------------------------------- void Bmp::drawLine( int x0, int y0, int x1, int y1, unsigned char red, unsigned char green, unsigned char blue ) { int xDelta = (x1 - x0); int yDelta = (y1 - y0); if(xDelta == 0) { // A vertical line if(y0 > y1) swap(y0, y1); for(int y = y0; y <= y1; y ++) setPixel(x0, y, red, green, blue); } else if(yDelta == 0) { // A horizontal line if(x0 > x1) swap(x0, x1); for(int x = x0; x <= x1; x ++) setPixel(x, y0, red, green, blue); } else { setPixel(x0, y0, red, green, blue); int xStep = (