Add mipmap scaling according to alphatest coverage.

This commit is contained in:
castano 2010-05-27 00:37:15 +00:00
parent 77bfabca3b
commit 8cbd2c9ec6
6 changed files with 105 additions and 9 deletions

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@ -194,10 +194,16 @@ void FloatImage::scaleBias(uint base_component, uint num, float scale, float bia
} }
/// Clamp the elements of the image. /// Clamp the elements of the image.
void FloatImage::clamp(float low, float high) void FloatImage::clamp(uint base_component, uint num, float low, float high)
{ {
for(uint i = 0; i < m_count; i++) { const uint size = m_width * m_height;
m_mem[i] = nv::clamp(m_mem[i], low, high);
for(uint c = 0; c < num; c++) {
float * ptr = this->channel(base_component + c);
for(uint i = 0; i < size; i++) {
ptr[i] = nv::clamp(ptr[i], low, high);
}
} }
} }
@ -945,6 +951,54 @@ void FloatImage::flip()
} }
} }
float FloatImage::alphaTestCoverage(float alphaRef, int alphaChannel) const
{
const uint w = m_width;
const uint h = m_height;
float coverage = 0.0f;
for (uint y = 0; y < h; y++) {
const float * alpha = scanline(y, alphaChannel);
for (uint x = 0; x < w; x++) {
if (alpha[x] > alphaRef) coverage += 1.0f; // @@ gt or lt?
}
}
return coverage / float(w * h);
}
void FloatImage::scaleAlphaToCoverage(float desiredCoverage, float alphaRef, int alphaChannel)
{
float minAlphaRef = 0.0f;
float maxAlphaRef = 1.0f;
float midAlphaRef = 0.5f;
// Determine desired scale using a binary search. Hardcoded to 8 steps max.
for (int i = 0; i < 8; i++) {
float currentCoverage = alphaTestCoverage(midAlphaRef, alphaChannel);
if (currentCoverage > desiredCoverage) {
maxAlphaRef = midAlphaRef;
}
else if (currentCoverage < desiredCoverage) {
minAlphaRef = midAlphaRef;
}
else {
break;
}
midAlphaRef = (minAlphaRef + maxAlphaRef) * 0.5f;
}
float alphaScale = alphaRef / midAlphaRef;
// Scale alpha channel.
scaleBias(alphaChannel, 1, alphaScale, 0.0f);
}
FloatImage* FloatImage::clone() const FloatImage* FloatImage::clone() const
{ {
FloatImage* copy = new FloatImage(); FloatImage* copy = new FloatImage();

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@ -59,10 +59,9 @@ public:
NVIMAGE_API void packNormals(uint base_component); NVIMAGE_API void packNormals(uint base_component);
NVIMAGE_API void expandNormals(uint base_component); NVIMAGE_API void expandNormals(uint base_component);
NVIMAGE_API void scaleBias(uint base_component, uint num, float scale, float add); NVIMAGE_API void scaleBias(uint base_component, uint num, float scale, float bias);
//NVIMAGE_API void clamp(uint base_component, uint num); NVIMAGE_API void clamp(uint base_component, uint num, float low, float high);
NVIMAGE_API void clamp(float low, float high);
NVIMAGE_API void toLinear(uint base_component, uint num, float gamma = 2.2f); NVIMAGE_API void toLinear(uint base_component, uint num, float gamma = 2.2f);
NVIMAGE_API void toGamma(uint base_component, uint num, float gamma = 2.2f); NVIMAGE_API void toGamma(uint base_component, uint num, float gamma = 2.2f);
@ -87,6 +86,9 @@ public:
NVIMAGE_API void applyKernelHorizontal(const PolyphaseKernel & k, int y, uint c, uint a, WrapMode wm, float * output) const; NVIMAGE_API void applyKernelHorizontal(const PolyphaseKernel & k, int y, uint c, uint a, WrapMode wm, float * output) const;
NVIMAGE_API void flip(); NVIMAGE_API void flip();
NVIMAGE_API float alphaTestCoverage(float alphaRef, int alphaChannel) const;
NVIMAGE_API void scaleAlphaToCoverage(float coverage, float alphaRef, int alphaChannel);
//@} //@}
uint width() const { return m_width; } uint width() const { return m_width; }

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@ -112,7 +112,7 @@ void OutputOptions::Private::beginImage(int size, int width, int height, int dep
bool OutputOptions::Private::writeData(const void * data, int size) const bool OutputOptions::Private::writeData(const void * data, int size) const
{ {
if (outputHandler != NULL) return outputHandler->writeData(data, size); return outputHandler == NULL || outputHandler->writeData(data, size);
} }
void OutputOptions::Private::error(Error e) const void OutputOptions::Private::error(Error e) const

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@ -244,6 +244,29 @@ int TexImage::countMipmaps() const
return ::countMipmaps(width(), height(), depth()); return ::countMipmaps(width(), height(), depth());
} }
float TexImage::alphaTestCoverage(float alphaRef/*= 0.5*/) const
{
int imageCount = 0.0f;
float coverage = 0.0f;
foreach (i, m->imageArray)
{
FloatImage * img = m->imageArray[i];
if (img == NULL) continue;
imageCount++;
coverage += img->alphaTestCoverage(alphaRef, 3);
}
if (imageCount > 0) {
return coverage / imageCount;
}
else {
return 0.0f;
}
}
bool TexImage::load(const char * fileName) bool TexImage::load(const char * fileName)
{ {
@ -937,6 +960,21 @@ void TexImage::fill(float red, float green, float blue, float alpha)
} }
} }
void TexImage::scaleAlphaToCoverage(float coverage, float alphaRef/*= 0.5f*/)
{
detach();
foreach (i, m->imageArray)
{
FloatImage * img = m->imageArray[i];
if (img == NULL) continue;
img->scaleAlphaToCoverage(coverage, alphaRef, 3);
}
}
// Set normal map options. // Set normal map options.
void TexImage::toNormalMap(float sm, float medium, float big, float large) void TexImage::toNormalMap(float sm, float medium, float big, float large)
{ {

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@ -412,6 +412,7 @@ namespace nvtt
NVTT_API AlphaMode alphaMode() const; NVTT_API AlphaMode alphaMode() const;
NVTT_API bool isNormalMap() const; NVTT_API bool isNormalMap() const;
NVTT_API int countMipmaps() const; NVTT_API int countMipmaps() const;
NVTT_API float alphaTestCoverage(float alphaRef = 0.5) const;
// Texture data. // Texture data.
NVTT_API bool load(const char * fileName); NVTT_API bool load(const char * fileName);
@ -424,7 +425,7 @@ namespace nvtt
NVTT_API void resize(int w, int h, ResizeFilter filter); NVTT_API void resize(int w, int h, ResizeFilter filter);
NVTT_API void resize(int maxExtent, RoundMode mode, ResizeFilter filter); NVTT_API void resize(int maxExtent, RoundMode mode, ResizeFilter filter);
NVTT_API bool buildNextMipmap(MipmapFilter filter); NVTT_API bool buildNextMipmap(MipmapFilter filter);
// Color transforms. // Color transforms.
NVTT_API void toLinear(float gamma); NVTT_API void toLinear(float gamma);
NVTT_API void toGamma(float gamma); NVTT_API void toGamma(float gamma);
@ -438,6 +439,7 @@ namespace nvtt
NVTT_API void toGreyScale(float redScale, float greenScale, float blueScale, float alphaScale); NVTT_API void toGreyScale(float redScale, float greenScale, float blueScale, float alphaScale);
NVTT_API void setBorder(float r, float g, float b, float a); NVTT_API void setBorder(float r, float g, float b, float a);
NVTT_API void fill(float r, float g, float b, float a); NVTT_API void fill(float r, float g, float b, float a);
NVTT_API void scaleAlphaToCoverage(float coverage, float alphaRef = 0.5f);
// Set normal map options. // Set normal map options.
NVTT_API void toNormalMap(float sm, float medium, float big, float large); NVTT_API void toNormalMap(float sm, float medium, float big, float large);

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@ -386,7 +386,7 @@ int main(int argc, char *argv[])
} }
else else
{ {
if (nv::strCaseCmp(input.extension(), ".exr") == 0) if (nv::strCaseCmp(input.extension(), ".exr") == 0 || nv::strCaseCmp(input.extension(), ".hdr") == 0)
{ {
loadAsFloat = true; loadAsFloat = true;
} }