1 files changed, 91 insertions, 0 deletions
diff --git a/utils/pfm2tgas/pfm2tgas.cpp b/utils/pfm2tgas/pfm2tgas.cpp
new file mode 100644
index 0000000..491d985
--- /dev/null
+++ b/utils/pfm2tgas/pfm2tgas.cpp
@@ -0,0 +1,91 @@
+//========= Copyright Valve Corporation, All rights reserved. ============//
+//
+// Purpose: 
+//
+//===========================================================================//
+
+#include <tier0/platform.h>
+#include "bitmap/float_bm.h"
+#include "mathlib/mathlib.h"
+#include <tier2/tier2.h>
+
+#define N_TEXTURES_OUTPUT 3
+#define TEXTURE_TO_TEXTURE_SCALE 8.0
+#define BASE_SCALE 0.25
+
+static float Truncate8( float f )
+{
+	uint8 px= (uint8) min(255.0, (f*255.0));
+	return px*(1.0/255.0);
+}
+
+static float ErrorWeights[]={ 0.3, 0.59, 0.11 };
+
+void main(int argc,char **argv)
+{
+	InitCommandLineProgram( argc, argv );
+	if ( argc==3)
+	{
+		FloatBitMap_t src_texture;
+		src_texture.LoadFromPFM( argv[1] );
+		float sfactor=atof(argv[2]);
+		// we will split the float texture into 2 textures.
+		FloatBitMap_t output_textures[N_TEXTURES_OUTPUT];
+		for(int o=0; o<N_TEXTURES_OUTPUT; o++)
+		{
+			output_textures[o].AllocateRGB( src_texture.Width, src_texture.Height );
+		}
+		for(int y=0; y < src_texture.Height; y++)
+			for(int x=0; x< src_texture.Width; x++)
+			{
+				for(int c=0;c<3;c++)
+					src_texture.Pixel(x,y,c) *= sfactor;
+				float curscale=BASE_SCALE;
+				float px_error[N_TEXTURES_OUTPUT];
+				float sum_error=0;
+				for(int o=0; o<N_TEXTURES_OUTPUT; o++)
+				{
+					px_error[o]=0.;
+					for(int c=0;c<3;c++)
+					{
+						float opixel=Truncate8( src_texture.Pixel( x, y, c )/curscale );
+
+						output_textures[o].Pixel( x, y, c )= opixel;
+						float expanded_pixel = curscale * opixel;
+						float err= fabs( src_texture.Pixel( x, y, c )- expanded_pixel );
+						if (src_texture.Pixel(x,y,c) > curscale)
+							err *=2;
+						px_error[o] += ErrorWeights[o] * err;
+					}
+					sum_error += px_error[o];
+					curscale *= TEXTURE_TO_TEXTURE_SCALE;
+				}
+				// now, set the weight for each map based upon closeness of fit between the scales
+				for(int o=0; o<N_TEXTURES_OUTPUT; o++)
+				{
+					if (sum_error == 0)						// possible, I guess, for black
+					{
+						if ( o == 0)
+							src_texture.Pixel(x, y, 3) = 1.0;
+						else
+							src_texture.Pixel(x, y, 3) = 0.0;
+					}
+					else
+						output_textures[o].Pixel(x, y, 3)=1.0-(px_error[o]/sum_error);
+				}
+			}
+		// now, output results
+		for(int o=0;o<N_TEXTURES_OUTPUT;o++)
+		{
+			char fnamebuf[1024];
+			strcpy(fnamebuf, argv[1]);
+			char *dot=strchr(fnamebuf,'.');
+			if (! dot)
+				dot=fnamebuf+strlen(fnamebuf);
+			sprintf(dot,"_%d.tga",o);
+			output_textures[o].WriteTGAFile(fnamebuf);
+		}
+	}
+	else
+		printf("format is 'pfm2tgas xxx.pfm scalefactor'\n");
+}