Targa.c

main() {

char* image = targa(100,200); fillRect(image,10,20,30,40,0xff0000ff); fillRect(image,20,30,40,50,0x80ff0000);

// Create a new targa image in memory char* targa(int width, height) { char* image = malloc(18+width*height*4); image[12] = width & 0xff00 >> 8; image[13] = width & 0xff; image[14] = height & 0xff00 >> 8; image[15] = height & 0xff; image[16] = 8; image[17] = ' '; return image; }

char* getOffset(char* image, int x,y) { int width = (int)((image[12]<<8)+image[13]); return image+18+4*(x+y*width); }

int getPixel(char* image, int x,y) { return *getOffset(image,x,y); }

void setPixel(char* image, int x,y,colour) { int i, col[3], a = colour >> 24; int col[0] = (colour & 0xff0000) >> 16; int col[1] = (colour & 0xff00) >> 8; int col[2] = colour & 0xff; char* pix = getOffset(image,x,y); for (i=1; i<4; i++) pix[i] = (char)(col[i]*a/255+pix[i]*(255-a)/255); }

void fillRect(char* image, int x1,y1,x2,y2,colour) { int x,y; for (y=y1; y<y2; y++) for (x=x1; x<x2; x++) setPixel(image,x,y,colour); } }