blender.cpp

这是一个有关3d的小程序

//////////////////////////////////////////////////////////////////////
// BLENDER           by Tobias Franke ([e-mail]) 2001 //
//////////////////////////////////////////////////////////////////////
//                                                                  //
//  This little program blends together two images by taking a bmp  //
//  as a sort of heightmap and then mixes two other bmps together!  //
//  The output is a file called final.bmp...                        //
//                                                                  //
//////////////////////////////////////////////////////////////////////


#include <stdio.h>
#include <math.h>
#include "bitmap.h"
#include "heightmap.h"

bitmap i1, i2, final;		//The bitmap objects
heightmap blender;			//The blender



//////////////////////////////////////////////////////////////////////
//   Thanks to Nicholas Anderson (http://www.flyingislands.co.uk)   //

float limit255(float a)		//Check for invalid values
{
	if(a < 0.0f) {
		return 0.0f;
	}
	else if(a > 255.0f) {
		return 255.0f;
	}
	else {
		return a;
	}
}

float texture_factor(int h1, float h2, float f)		//Check for percentage of color
{
	float t;
	t = (f - (float)abs(h1 - (int)h2)) / f;

	if(t < 0.0f) t = 0.0f;
	else if(t > 1.0f) t = 1.0f;

	return t;
}

// These two functions were taken and sligthly modified from        //
// N.Andersons LOD Program                                          //
//////////////////////////////////////////////////////////////////////



bool init()
{
	if (!i1.load("i1.bmp") || !i2.load("i2.bmp") || !blender.load("blender.bmp"))			//Load all images
	{	printf ("couldn't load all files...\n"); return false;	}

	if ((i1.getheight() != i2.getheight()) || (i1.getwidth() != i2.getwidth()))				//Check if i1 and i2 are of the same size
	{	printf ("images aren't of the same size...\n");	return false;	}

	if ((i1.getheight() != blender.getheight()) || (i1.getwidth() != blender.getwidth()))	//Check if blender is of the same size as i1 and i2
	{	printf ("images aren't the same size as blender...\n"); return false;	}

	final.create (i1.getwidth(), i1.getheight());											//Create new bitmap

	printf ("all images loaded, ready...\n");
	return true;
}

bool blend()
{
	float h1,f0, f1;												//h1 is heigtmap value at position x/z, f0 and f1 are percentage of color resulting due to the heightmap value stored in h1
	unsigned char r[2], g[2], b[2], new_r, new_g, new_b;			//Store color at pixel x/z of both images (i1 and i2), store the new calculated values

	for (int z=0; z<i1.getheight(); z++)							//Go through all pixels
		for (int x=0; x<i2.getwidth(); x++)
		{
			h1 = limit255(blender.hmap[x + (z*blender.getwidth())]);//Get proper heightmap value at x/z
	
			f0 = texture_factor(0,		h1,	256);					//Get percentage of color of pixel x/z from bitmap1, if height is zero (black) then bitmap1 receives 100%
			f1 = texture_factor(256,	h1, 256);					//Get percentage of color of pixel x/z from bitmap2, if height is 256  (white) then bitmap2 receives 100%
			
			i1.getcolor(x, z, &r[0], &g[0], &b[0]);					//Get color of pixel x/z from bitmap1
			i2.getcolor(x, z, &r[1], &g[1], &b[1]);					//Get color of pixel x/z from bitmap2

			new_r = (unsigned)limit255((r[0] * f0) + (r[1] * f1));	//Calculate new r value for the pixel to be written
			new_g = (unsigned)limit255((g[0] * f0) + (g[1] * f1));	//Calculate new g value for the pixel to be written
			new_b = (unsigned)limit255((b[0] * f0) + (b[1] * f1));	//Calculate new b value for the pixel to be written
	
			final.setcolor(x, z, new_r, new_g, new_b);				//Set new pixel color in final
		}
	if (!final.save ("final.bmp"))									//Save bitmap
	{	printf ("couldn't save final image...\n"); return false;	}
	else
	{	printf ("images blended, see final.bmp...\n"); return true;	}
}

void main()
{
	printf ("Blender v0.02 by Tobias Franke\n\n");
	printf ("blending...\n");

	if (init())
		{ if (!blend()) printf ("terminating(error)...\n"); }
	else
		printf ("terminating(done)...\n");
}