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Improved floating point random number generation.

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Fixed loading RGB images, as reported in issue 15.
Moved pixel format conversion helpers to PixelFormat.h
This commit is contained in:
castano 2007-10-08 00:56:58 +00:00
parent c9c7c42d2b
commit e7aca55ba3
5 changed files with 131 additions and 91 deletions
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50
src/nvimage/DirectDrawSurface.cpp
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@ -29,6 +29,7 @@
#include <nvimage/ColorBlock.h>
#include <nvimage/Image.h>
#include <nvimage/BlockDXT.h>
#include <nvimage/PixelFormat.h>
#include <string.h> // memset
@ -765,39 +766,6 @@ void DirectDrawSurface::mipmap(Image * img, uint face, uint mipmap)
}
}
// @@ Move this code to format conversion!!
namespace
{
static uint convert(uint c, uint inbits, uint outbits)
{
if (inbits <= outbits)
{
// truncate
return c >> (inbits - outbits);
}
else
{
// bitexpand
return (c << (outbits - inbits)) | convert(c, inbits, outbits - inbits);
}
}
static void maskShiftAndSize(uint mask, uint * shift, uint * size)
{
*shift = 0;
while((mask & 1) == 0) {
++(*shift);
mask >>= 1;
}
*size = 0;
while((mask & 1) == 1) {
++(*size);
mask >>= 1;
}
}
}
void DirectDrawSurface::readLinearImage(Image * img)
{
nvDebugCheck(stream != NULL);
@ -807,16 +775,16 @@ void DirectDrawSurface::readLinearImage(Image * img)
const uint h = img->height();
uint rshift, rsize;
maskShiftAndSize(header.pf.rmask, &rshift, &rsize);
PixelFormat::maskShiftAndSize(header.pf.rmask, &rshift, &rsize);
uint gshift, gsize;
maskShiftAndSize(header.pf.gmask, &gshift, &gsize);
PixelFormat::maskShiftAndSize(header.pf.gmask, &gshift, &gsize);
uint bshift, bsize;
maskShiftAndSize(header.pf.bmask, &bshift, &bsize);
PixelFormat::maskShiftAndSize(header.pf.bmask, &bshift, &bsize);
uint ashift, asize;
maskShiftAndSize(header.pf.amask, &ashift, &asize);
PixelFormat::maskShiftAndSize(header.pf.amask, &ashift, &asize);
uint byteCount = (header.pf.bitcount + 7) / 8;
@ -834,10 +802,10 @@ void DirectDrawSurface::readLinearImage(Image * img)
stream->serialize(&c, byteCount);
Color32 pixel(0, 0, 0, 0xFF);
pixel.r = convert(c >> rshift, rsize, 8);
pixel.g = convert(c >> gshift, gsize, 8);
pixel.b = convert(c >> bshift, bsize, 8);
pixel.a = convert(c >> ashift, asize, 8);
pixel.r = PixelFormat::convert(c >> rshift, rsize, 8);
pixel.g = PixelFormat::convert(c >> gshift, gsize, 8);
pixel.b = PixelFormat::convert(c >> bshift, bsize, 8);
pixel.a = PixelFormat::convert(c >> ashift, asize, 8);
img->pixel(x, y) = pixel;
}

84
src/nvimage/PixelFormat.h Normal file
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@ -0,0 +1,84 @@
// Copyright NVIDIA Corporation 2007 -- Ignacio Castano <icastano@nvidia.com>
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
#ifndef NV_IMAGE_PIXELFORMAT_H
#define NV_IMAGE_PIXELFORMAT_H
#include <nvimage.h>
// @@ Move this code to format conversion!!
namespace nv
{
namespace PixelFormat
{
// Convert component @a c having @a inbits to the returned value having @a outbits.
inline uint convert(uint c, uint inbits, uint outbits)
{
if (inbits == 0)
{
return 0;
}
else if (inbits >= outbits)
{
// truncate
return c >> (inbits - outbits);
}
else
{
// bitexpand
return (c << (outbits - inbits)) | convert(c, inbits, outbits - inbits);
}
}
// Get pixel component shift and size given its mask.
static void maskShiftAndSize(uint mask, uint * shift, uint * size)
{
if (!mask)
{
*shift = 0;
*size = 0;
return;
}
*shift = 0;
while((mask & 1) == 0) {
++(*shift);
mask >>= 1;
}
*size = 0;
while((mask & 1) == 1) {
++(*size);
mask >>= 1;
}
}
} // PixelFormat namespace
} // nv namespace
#endif // NV_IMAGE_PIXELFORMAT_H

55
src/nvimage/nvtt/CompressRGB.cpp
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@ -24,6 +24,7 @@
#include <nvcore/Debug.h>
#include <nvimage/Image.h>
#include <nvimage/PixelFormat.h>
#include <nvmath/Color.h>
#include "CompressRGB.h"
@ -54,35 +55,6 @@ namespace
memcpy(dst, src, 4 * w);
}
static uint convert(uint c, uint inbits, uint outbits)
{
if (inbits <= outbits)
{
// truncate
return c >> (inbits - outbits);
}
else
{
// bitexpand
return (c << (outbits - inbits)) | convert(c, inbits, outbits - inbits);
}
}
static void maskShiftAndSize(uint mask, uint * shift, uint * size)
{
*shift = 0;
while((mask & 1) == 0) {
++(*shift);
mask >>= 1;
}
*size = 0;
while((mask & 1) == 1) {
++(*size);
mask >>= 1;
}
}
} // namespace
@ -101,21 +73,19 @@ void nv::compressRGB(const Image * image, const OutputOptions & outputOptions, c
const uint rmask = compressionOptions.rmask;
uint rshift, rsize;
maskShiftAndSize(rmask, &rshift, &rsize);
PixelFormat::maskShiftAndSize(rmask, &rshift, &rsize);
const uint gmask = compressionOptions.gmask;
uint gshift, gsize;
maskShiftAndSize(gmask, &gshift, &gsize);
PixelFormat::maskShiftAndSize(gmask, &gshift, &gsize);
const uint bmask = compressionOptions.bmask;
uint bshift, bsize;
maskShiftAndSize(bmask, &bshift, &bsize);
PixelFormat::maskShiftAndSize(bmask, &bshift, &bsize);
const uint amask = compressionOptions.amask;
uint ashift, asize;
maskShiftAndSize(amask, &ashift, &asize);
// @@ Perform error diffusion dithering.
PixelFormat::maskShiftAndSize(amask, &ashift, &asize);
// Determine pitch.
uint pitch = computePitch(w, compressionOptions.bitcount);
@ -140,13 +110,16 @@ void nv::compressRGB(const Image * image, const OutputOptions & outputOptions, c
for (uint x = 0; x < w; x++)
{
uint c = 0;
c |= convert(src[x].r, 8, rsize) << rshift;
c |= convert(src[x].g, 8, gsize) << gshift;
c |= convert(src[x].b, 8, bsize) << bshift;
c |= convert(src[x].a, 8, asize) << ashift;
c |= PixelFormat::convert(src[x].r, 8, rsize) << rshift;
c |= PixelFormat::convert(src[x].g, 8, gsize) << gshift;
c |= PixelFormat::convert(src[x].b, 8, bsize) << bshift;
c |= PixelFormat::convert(src[x].a, 8, asize) << ashift;
// @@ This is wrong, this pixels overlaps with the previous one!
*(uint *)(dst + x * byteCount) = c;
// Output one byte at a time. @@ Not tested... Does this work on LE and BE?
for (int i = 0; i < byteCount; i++)
{
*(dst + x * byteCount) = (c >> (i * 8)) & 0xFF;
}
}
}

14
src/nvmath/Montecarlo.cpp
View File

@ -28,8 +28,8 @@ void SampleDistribution::redistributeRandom(const Distribution dist)
// This is the worst method possible!
for(uint i = 0; i < sampleCount; i++)
{
float x = m_rand.getReal();
float y = m_rand.getReal();
float x = m_rand.getFloat();
float y = m_rand.getFloat();
// Map uniform distribution in the square to the (hemi)sphere.
if( dist == Distribution_Uniform ) {
@ -53,8 +53,8 @@ void SampleDistribution::redistributeStratified(const Distribution dist)
// Create a uniform distribution of points on the hemisphere with low variance.
for(uint v = 0, i = 0; v < sqrtSampleCount; v++) {
for(uint u = 0; u < sqrtSampleCount; u++, i++) {
float x = (u + m_rand.getReal()) / float(sqrtSampleCount);
float y = (v + m_rand.getReal()) / float(sqrtSampleCount);
float x = (u + m_rand.getFloat()) / float(sqrtSampleCount);
float y = (v + m_rand.getFloat()) / float(sqrtSampleCount);
// Map uniform distribution in the square to the (hemi)sphere.
if( dist == Distribution_Uniform ) {
@ -82,7 +82,7 @@ void SampleDistribution::multiStageNRooks(const int size, int* cells)
int size2 = size >> 1;
if (size & 1) {
if (m_rand.getReal() > 0.5) {
if (m_rand.getFloat() > 0.5) {
size1++;
}
else {
@ -138,8 +138,8 @@ void SampleDistribution::redistributeNRook(const Distribution dist)
for(uint i = 0; i < sampleCount; i++)
{
float x = (i + m_rand.getReal()) / sampleCount;
float y = (cells[i] + m_rand.getReal()) / sampleCount;
float x = (i + m_rand.getFloat()) / sampleCount;
float y = (cells[i] + m_rand.getFloat()) / sampleCount;
// Map uniform distribution in the square to the (hemi)sphere.
if( dist == Distribution_Uniform ) {

19
src/nvmath/Random.h
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@ -35,6 +35,20 @@ public:
return n;
}
/// Random number on [0.0, 1.0] interval.
float getFloat()
{
union
{
uint32 i;
float f;
} pun;
pun.i = 0x3f800000UL | (get() & 0x007fffffUL);
return pun.f - 1.0f;
}
/*
/// Random number on [0.0, 1.0] interval.
double getReal()
{
@ -45,7 +59,8 @@ public:
double getRealExclusive()
{
return double(get()) * (1.0/4294967296.0); // 2^32
}
}
*/
/// Get the max value of the random number.
uint max() const { return 4294967295U; }
@ -301,7 +316,7 @@ public:
}
/** Get a random number. */
virtual uint Get() {
virtual uint get() {
advance();