Merge

--HG--
branch : trunk

1 files changed, 1065 insertions, 0 deletions

diff --git a/externals/g3dlite/G3D.lib/source/GImage.cpp b/externals/g3dlite/G3D.lib/source/GImage.cpp
new file mode 100644
index 00000000000..c7abf982553
--- /dev/null
+++ b/externals/g3dlite/G3D.lib/source/GImage.cpp
@@ -0,0 +1,1065 @@
+/**
+  @file GImage.cpp
+  @author Morgan McGuire, morgan@graphics3d.com
+  Copyright 2002-2007, Morgan McGuire
+
+  @created 2002-05-27
+  @edited  2006-10-10
+ */
+#include "G3D/platform.h"
+#include "G3D/GImage.h"
+#include "G3D/debug.h"
+#include "G3D/stringutils.h"
+#include "G3D/TextInput.h"
+#include "G3D/TextOutput.h"
+#include "G3D/BinaryInput.h"
+#include "G3D/BinaryOutput.h"
+#include "G3D/Log.h"
+#include <png.h>
+#include <sys/stat.h>
+#include <assert.h>
+#include <sys/types.h>
+
+//////////////////////////////////////////////////////////////////////////////////////////////
+
+namespace G3D {
+   
+void GImage::RGBtoRGBA(
+    const uint8*    in,
+    uint8*          out,
+    int             numPixels) {
+
+    for (int i = 0; i < numPixels; ++i) {
+        int i3 = i * 3;
+        int i4 = i3 + i;
+
+        out[i4 + 0] = in[i3 + 0]; 
+        out[i4 + 1] = in[i3 + 1]; 
+        out[i4 + 2] = in[i3 + 2]; 
+        out[i4 + 3] = 255; 
+    }
+}
+
+
+void GImage::RGBAtoRGB(
+    const uint8*    in,
+    uint8*          out,
+    int             numPixels) {
+
+    for (int i = 0; i < numPixels; ++i) {
+        int i3 = i * 3;
+        int i4 = i3 + i;
+
+        out[i3 + 0] = in[i4 + 0]; 
+        out[i3 + 1] = in[i4 + 1]; 
+        out[i3 + 2] = in[i4 + 2]; 
+    }
+}
+
+
+void GImage::RGBtoBGRA(
+    const uint8*    in,
+    uint8*          out,
+    int                     numPixels) {
+
+    for (int i = 0; i < numPixels; ++i) {
+        int i3 = i * 3;
+        int i4 = i3 + i;
+
+        out[i4 + 2] = in[i3 + 0]; 
+        out[i4 + 1] = in[i3 + 1]; 
+        out[i4 + 0] = in[i3 + 2]; 
+        out[i4 + 3] = 255; 
+    }
+}
+
+
+
+void GImage::RGBtoBGR(
+    const uint8*    in,
+    uint8*          out,
+    int             numPixels) {
+
+    for (int i = 0; i < numPixels; ++i) {
+        int i3 = i * 3;
+
+        int r = in[i3 + 0];
+        int g = in[i3 + 1];
+        int b = in[i3 + 2];
+
+        out[i3 + 2] = r; 
+        out[i3 + 1] = g; 
+        out[i3 + 0] = b;
+    }
+}
+
+
+void GImage::RGBxRGBtoRGBA(
+    const uint8*            colorRGB,
+    const uint8*            alphaRGB,
+    uint8*                  out,
+    int                     numPixels) {
+
+    for (int i = numPixels - 1; i >= 0; --i) {
+        int i3 = i * 3;
+        int i4 = i3 + i;
+
+        out[i4 + 0] = colorRGB[i3 + 0];
+        out[i4 + 1] = colorRGB[i3 + 1];
+        out[i4 + 2] = colorRGB[i3 + 2];
+        out[i4 + 3] = alphaRGB[i3 + 0];
+    }
+}
+
+
+void GImage::RGBtoARGB(
+    const uint8*            in,
+    uint8*                  out,
+    int                     numPixels) {
+
+    for (int i = 0; i < numPixels; ++i) {
+        int i3 = i * 3;
+        int i4 = i3 + i;
+
+        out[i4 + 0] = 255; 
+        out[i4 + 1] = in[i3 + 0]; 
+        out[i4 + 2] = in[i3 + 1]; 
+        out[i4 + 3] = in[i3 + 2];
+    }
+}
+
+
+void GImage::flipRGBVertical(
+    const uint8*            in,
+    uint8*                  out,
+    int                     width,
+    int                     height) {
+
+    
+    // Allocate a temp row so the operation
+    // is still safe if in == out
+    uint8* temp = (uint8*)System::malloc(width * 3);
+    alwaysAssertM(temp != NULL, "Out of memory"); 
+
+    int oneRow = width * 3;
+    int N = height / 2;
+
+    // if height is an odd value, don't swap odd middle row
+    for (int i = 0; i < N; ++i) {
+        int topOff = i * oneRow;
+        int botOff = (height - i - 1) * oneRow;
+        System::memcpy(temp,         in + topOff, oneRow);
+        System::memcpy(out + topOff, in + botOff, oneRow);
+        System::memcpy(out + botOff, temp,        oneRow);
+    }
+
+    System::free(temp);
+}
+
+
+void GImage::flipRGBAVertical(
+    const uint8*            in,
+    uint8*                  out,
+    int                     width,
+    int                     height) {
+
+    
+    // Allocate a temp row so the operation
+    // is still safe if in == out
+    uint8* temp = (uint8*)System::malloc(width * 4);
+    alwaysAssertM(temp != NULL, "Out of memory");
+
+    int oneRow = width * 4;
+
+    // if height is an odd value, don't swap odd middle row
+    for (int i = 0; i < height / 2; ++i) {
+        int topOff = i * oneRow;
+        int botOff = (height - i - 1) * oneRow;
+        System::memcpy(temp,         in + topOff, oneRow);
+        System::memcpy(out + topOff, in + botOff, oneRow);
+        System::memcpy(out + botOff, temp,        oneRow);
+    }
+
+    System::free(temp);
+}
+
+////////////////////////////////////////////////////////////////////////////////////////
+
+void GImage::decode(
+    BinaryInput&        input,
+    Format              format) {
+
+    switch (format) {
+    case PPM_ASCII:
+        decodePPMASCII(input);
+        break;
+
+    case PPM:
+        decodePPM(input);
+        break;
+
+    case PNG:
+        decodePNG(input);
+        break;
+
+    case JPEG:
+        decodeJPEG(input);
+        break;
+
+    case TGA:
+        decodeTGA(input);
+        break;
+
+    case BMP:
+        decodeBMP(input);
+        break;
+
+    case ICO:
+        decodeICO(input);
+        break;
+
+    case PCX:
+        decodePCX(input);
+        break;
+
+    default:
+        debugAssert(false);
+    }
+
+    debugAssert(width >= 0);
+    debugAssert(height >= 0);
+    debugAssert(channels == 1 || channels == 3 || channels == 4);
+    debugAssert(_byte != NULL);
+}
+
+
+void GImage::decodePCX(
+    BinaryInput&                input) {
+
+    uint8  manufacturer = input.readUInt8();
+    uint8  version      = input.readUInt8();
+    uint8  encoding     = input.readUInt8();
+    uint8  bitsPerPixel = input.readUInt8();
+
+    uint16 xmin         = input.readUInt16();
+    uint16 ymin         = input.readUInt16();
+    uint16 xmax         = input.readUInt16();
+    uint16 ymax         = input.readUInt16();
+
+    uint16 horizDPI     = input.readUInt16();
+    uint16 vertDPI      = input.readUInt16();
+
+    Color3uint8 colorMap[16];
+    input.readBytes(colorMap, 48);
+
+    input.skip(1);
+
+    uint8  planes       = input.readUInt8();
+    uint16 bytesPerLine = input.readUInt16();
+    uint16 paletteType  = input.readUInt16();
+    input.skip(4 + 54);
+
+    (void)bytesPerLine;
+
+    width  = xmax - xmin + 1;
+    height = ymax - ymin + 1;
+    channels = 3;
+
+    if ((manufacturer != 0x0A) || (encoding != 0x01)) {
+        throw GImage::Error("PCX file is corrupted", input.getFilename());
+    }
+
+    (void)version;
+    (void)vertDPI;
+    (void)horizDPI;
+
+    if ((bitsPerPixel != 8) || ((planes != 1) && (planes != 3))) {
+        throw GImage::Error("Only 8-bit paletted and 24-bit PCX files supported.", input.getFilename());
+    }
+
+	// Prepare the pointer object for the pixel data
+    _byte = (uint8*)System::malloc(width * height * 3);
+
+    if ((paletteType == 1) && (planes == 3)) {
+
+        Color3uint8* pixel = pixel3();
+
+        // Iterate over each scan line
+        for (int row = 0; row < height; ++row) {
+            // Read each scan line once per plane
+            for (int plane = 0; plane < planes; ++plane) {
+                int p = row * width;
+                int p1 = p + width;
+                while (p < p1) {
+                    uint8 value = input.readUInt8();
+                    int length = 1;
+            
+                    if (value >= 192) {
+                        // This is the length, not the value.  Mask off
+                        // the two high bits and read the true index.
+                        length = value & 0x3F;
+                        value = input.readUInt8();
+                    }
+
+                    // Set the whole run
+                    for (int i = length - 1; i >= 0; --i, ++p) {
+                        debugAssert(p < width * height);
+                        pixel[p][plane] = value;
+                    }
+                }
+            }
+        }
+
+    } else if (planes == 1) {
+
+        Color3uint8 palette[256];
+
+        int imageBeginning   = input.getPosition();
+        int paletteBeginning = input.getLength() - 769;
+
+        input.setPosition(paletteBeginning);
+
+        uint8 dummy = input.readUInt8();
+
+        if (dummy != 12) {
+            Log::common()->println("\n*********************");
+            Log::common()->printf("Warning: Corrupted PCX file (palette marker byte was missing) \"%s\"\nLoading anyway\n\n", input.getFilename().c_str());
+        }
+
+        input.readBytes(palette, sizeof(palette));
+        input.setPosition(imageBeginning);
+        
+        Color3uint8* pixel = pixel3();
+        
+        // The palette indices are run length encoded.
+        int p = 0;
+        while (p < width * height) {
+            uint8 index  = input.readUInt8();
+            uint8 length = 1;
+
+            if (index >= 192) {
+                // This is the length, not the index.  Mask off
+                // the two high bits and read the true index.
+                length = index & 0x3F;
+                index  = input.readUInt8();
+            }
+
+            Color3uint8 color = palette[index];
+
+            // Set the whole run
+            for (int i = length - 1; i >= 0; --i, ++p) {
+                if (p > width * height) {
+                    break;
+                }
+                pixel[p] = color;
+            }
+
+        }
+
+    } else {
+        throw GImage::Error("Unsupported PCX file type.", input.getFilename());
+    }
+}
+
+
+GImage::Format GImage::resolveFormat(const std::string&  filename) {
+    BinaryInput b(filename, G3D_LITTLE_ENDIAN);
+    if (b.size() <= 0) {
+        throw Error("File not found.", filename);
+    }
+
+    return resolveFormat(filename, b.getCArray(), b.size(), AUTODETECT);
+}
+
+
+GImage::Format GImage::resolveFormat(
+    const std::string&  filename,
+    const uint8*        data,
+    int                 dataLen,
+    Format              maybeFormat) {
+
+    // Return the provided format if it is specified.
+    if (maybeFormat != AUTODETECT) {
+        return maybeFormat;
+    }
+
+    std::string extension;
+
+    // Try to detect from the filename's extension
+    if (filename.size() >= 5) {
+        int n = iMax(filename.size() - 1, 5);
+        // Search backwards for the "."
+        for (int i = 1; i <= n; ++i) {
+            if (filename[filename.size() - i] == '.') {
+                // Upper case
+                extension = toUpper(filename.substr(filename.size() - i + 1));
+                break;
+            }
+        }
+    }
+
+    if (extension == "PPM") {
+        // There are two PPM formats; we handle them differently
+        if (dataLen > 3) {
+            if (!memcmp(data, "P6", 2)) {
+                return PPM;
+            } else {
+                return PPM_ASCII;
+            }
+        }
+    }
+
+    Format tmp = stringToFormat(extension);
+    if ((tmp != AUTODETECT) && (tmp != UNKNOWN)) {
+        return tmp;
+    }
+
+    // Try and autodetect from the file itself by looking at the first
+    // character.
+
+    // We can't look at the character if it is null.
+    debugAssert(data != NULL);              
+
+    if ((dataLen > 3) && (!memcmp(data, "P3", 2) || !memcmp(data, "P2", 2) || !memcmp(data, "P1", 2))) {
+        return PPM_ASCII;
+    }
+
+    if ((dataLen > 3) && !memcmp(data, "P6", 2)) {
+        return PPM;
+    }
+
+    if (dataLen > 8) {
+        if (!png_sig_cmp((png_bytep)data, 0, 8))
+            return PNG;
+    }
+
+    if ((dataLen > 0) && (data[0] == 'B')) {
+        return BMP;
+    }
+
+    if (dataLen > 10) {
+        if ((dataLen > 11) && (data[0] == 0xFF) &&
+            (memcmp(&data[6], "JFIF", 4) == 0)) {
+            return JPEG;
+        }
+    }
+
+    if (dataLen > 40) {
+        if (memcmp(&data[dataLen - 18], "TRUEVISION-XFILE", 16) == 0) {
+            return TGA;
+        }
+    }
+
+    if ((dataLen > 4) && (data[0] == 0) && (data[1] == 0) && (data[2] == 0) && (data[3] == 1)) {
+        return ICO;
+    }
+
+    if ((dataLen > 0) && (data[0] == 10)) {
+        return PCX;
+    }
+
+    return UNKNOWN;
+}
+
+
+GImage::GImage(
+    const std::string&  filename,
+    Format              format) : 
+    _byte(NULL), 
+    width(0),
+    height(0), 
+    channels(0){
+    
+    load(filename, format);
+}
+
+
+void GImage::load(
+    const std::string&  filename,
+    Format              format) {
+
+    clear();
+
+    try {
+        BinaryInput b(filename, G3D_LITTLE_ENDIAN);
+        if (b.size() <= 0) {
+            throw Error("File not found.", filename);
+        }
+
+        alwaysAssertM(this != NULL, "Corrupt GImage");
+        decode(b, resolveFormat(filename, b.getCArray(), b.size(), format));
+    } catch (const std::string& error) {
+        throw Error(error, filename);
+    }
+}
+
+
+GImage::GImage(
+    const uint8*        data,
+    int                 length,
+    Format              format) {
+
+    BinaryInput b(data, length, G3D_LITTLE_ENDIAN);
+    // It is safe to cast away the const because we
+    // know we don't corrupt the data.
+
+    decode(b, resolveFormat("", data, length, format));
+}
+
+
+GImage::GImage(
+    int                 width,
+    int                 height,
+    int                 channels) {
+    
+    _byte = NULL;
+    resize(width, height, channels);
+}
+
+
+void GImage::resize(
+    int                 width,
+    int                 height,
+    int                 channels) {
+    debugAssert(width >= 0);
+    debugAssert(height >= 0);
+    debugAssert(channels >= 1);
+
+    clear();
+
+    this->width = width;
+    this->height = height;
+    this->channels = channels;
+    size_t sz = width * height * channels;
+
+    _byte = (uint8*)System::calloc(sz, sizeof(uint8));
+    debugAssert(isValidHeapPointer(_byte));
+}
+
+
+void GImage::_copy(
+    const GImage&       other) {
+
+    clear();
+
+    width  = other.width;
+    height = other.height;
+    channels = other.channels;
+    int s  = width * height * channels * sizeof(uint8);
+    _byte  = (uint8*)System::malloc(s);
+    debugAssert(isValidHeapPointer(_byte));
+    memcpy(_byte, other._byte, s);
+}
+
+
+GImage::GImage(
+    const GImage&        other) : _byte(NULL) {
+
+    _copy(other);
+}
+
+
+GImage::~GImage() {
+    clear();
+}
+
+
+void GImage::clear() {
+    width = 0;
+    height = 0;
+    System::free(_byte);
+    _byte = NULL;
+}
+
+
+GImage& GImage::operator=(const GImage& other) {
+    _copy(other);
+    return *this;
+}
+
+
+bool GImage::copySubImage(
+    GImage & dest, const GImage & src,
+    int srcX, int srcY, int srcWidth, int srcHeight) {
+    if ((src.width < srcX + srcWidth) ||
+        (src.height < srcY + srcHeight) ||
+        (srcY < 0) ||
+        (srcX < 0)) {
+
+        return false;
+    }
+
+    dest.resize(srcWidth, srcHeight, src.channels);
+    
+    bool ret;
+    ret = pasteSubImage(dest, src, 0, 0, srcX, srcY, srcWidth, srcHeight);
+    debugAssert(ret);
+
+    return true;
+}
+
+
+bool GImage::pasteSubImage(
+    GImage & dest, const GImage & src,
+    int destX, int destY,
+    int srcX, int srcY, int srcWidth, int srcHeight) {
+    if ((src.width < srcX + srcWidth) ||
+        (src.height < srcY + srcHeight) ||
+        (dest.width < destX + srcWidth) ||
+        (dest.height < destY + srcHeight) ||
+        (srcY < 0) ||
+        (srcX < 0) ||
+        (destY < 0) ||
+        (destX < 0) ||
+        (src.channels != dest.channels)) {
+
+        return false;
+    }
+
+    for (int i = 0; i < srcHeight; i++) {
+        const uint8* srcRow = src.byte() +
+            ((i + srcY) * src.width + srcX) * src.channels;
+        uint8* destRow = dest.byte() +
+            ((i + destY) * dest.width + destX) * dest.channels;
+        memcpy(destRow, srcRow, srcWidth * src.channels);
+    }
+
+    return true;
+}
+
+
+bool GImage::supportedFormat(
+    const std::string& format) {
+
+    return (stringToFormat(format) != UNKNOWN);
+}
+
+
+GImage::Format GImage::stringToFormat(
+    const std::string& format) {
+
+    std::string extension = toUpper(format);
+
+    if ((extension == "JPG") || (extension == "JPEG")) {
+        return JPEG;
+    } else if (extension == "TGA") {
+        return TGA;
+    } else if (extension == "BMP") {
+        return BMP;
+    } else if (extension == "PCX") {
+        return PCX;
+    } else if (extension == "ICO") {
+        return ICO;
+    } else if (extension == "PNG") {
+        return PNG;
+    } else if (extension == "PPM") {
+        return PPM;
+    } else {
+        return UNKNOWN;
+    }
+}
+
+
+void GImage::save(
+    const std::string& filename,
+    Format             format) const {
+
+    BinaryOutput b(filename, G3D_LITTLE_ENDIAN);
+    encode(resolveFormat(filename, NULL, 0, format), b);
+    b.commit(false);
+}
+
+
+void GImage::encode(
+    Format              format,
+    uint8*&             outData,
+    int&                outLength) const {
+
+    BinaryOutput out;
+
+    encode(format, out);
+
+    outData = (uint8*)System::malloc(out.size());
+    debugAssert(outData);
+    outLength = out.size();
+
+    out.commit(outData);
+}
+
+
+void GImage::encode(
+    Format              format,
+    BinaryOutput&       out) const {
+
+    switch (format) {
+    case PPM_ASCII:
+        encodePPMASCII(out);
+        break;
+
+    case PPM:
+        encodePPM(out);
+        break;
+
+    case PNG:
+        encodePNG(out);
+        break;
+
+    case JPEG:
+        encodeJPEG(out);
+        break;
+
+    case BMP:
+        encodeBMP(out);
+        break;
+
+    case TGA:
+        encodeTGA(out);
+        break;
+
+    default:
+        debugAssert(false);
+    }
+}
+
+void GImage::insertRedAsAlpha(const GImage& alpha, GImage& output) const {
+    debugAssert(alpha.width == width);
+    debugAssert(alpha.height == height);
+
+    // make sure output GImage is valid
+    if (output.width != width || output.height != height || output.channels != 4) {
+        output.resize(width, height, 4);
+    }
+
+    for (int i = 0; i < width * height; ++i) {
+        output.byte()[i * 4 + 0] = byte()[i * channels + 0];
+        output.byte()[i * 4 + 1] = byte()[i * channels + 1];
+        output.byte()[i * 4 + 2] = byte()[i * channels + 2];
+        output.byte()[i * 4 + 3] = alpha.byte()[i * alpha.channels];
+    }
+}
+
+GImage GImage::insertRedAsAlpha(const GImage& alpha) const {
+    debugAssert(alpha.width == width);
+    debugAssert(alpha.height == height);
+
+    GImage out(width, height, 4);
+
+    insertRedAsAlpha(alpha, out);
+
+    return out;
+}
+
+
+void GImage::stripAlpha(GImage& output) const {
+
+    if (output.width != width || output.height != height || output.channels != 3)
+    {
+        output.resize(width, height, 3);
+    }
+
+    for (int i = 0; i < width * height; ++i) {
+        output.byte()[i * 3 + 0] = byte()[i * channels + 0];
+        output.byte()[i * 3 + 1] = byte()[i * channels + 1];
+        output.byte()[i * 3 + 2] = byte()[i * channels + 2];
+    }
+}
+
+GImage GImage::stripAlpha() const {
+    GImage out(width, height, 3);
+
+    stripAlpha(out);
+
+    return out;
+}
+
+
+int GImage::sizeInMemory() const {
+    return sizeof(GImage) + width * height * channels;
+}
+
+
+void GImage::computeNormalMap(
+    const GImage&       bump,
+    GImage&             normal,
+    float               whiteHeightInPixels,
+    bool                lowPassBump,
+    bool                scaleHeightByNz) {
+    computeNormalMap(bump.width, bump.height, bump.channels, bump.byte(), normal, whiteHeightInPixels, lowPassBump, scaleHeightByNz);
+}
+
+void GImage::computeNormalMap(
+    int                 width,
+    int                 height,
+    int                 channels,
+    const uint8*        src,
+    GImage&             normal,
+    float               whiteHeightInPixels,
+    bool                lowPassBump,
+    bool                scaleHeightByNz) {
+
+    if (whiteHeightInPixels == -1.0f) {
+        // Default setting scales so that a gradient ramp
+        // over the whole image becomes a 45-degree angle
+        
+        // Account for potentially non-square aspect ratios
+        whiteHeightInPixels = max(width, height);
+    }
+
+    debugAssert(whiteHeightInPixels >= 0);
+
+    const int w = width;
+    const int h = height;
+    const int stride = channels;
+
+    normal.resize(w, h, 4);
+
+    const uint8* const B = src;
+    Color4uint8* const N = normal.pixel4();
+
+    for (int y = 0; y < h; ++y) {
+        for (int x = 0; x < w; ++x) {
+            // Index into normal map pixel
+            int i = x + y * w;
+
+            // Index into bump map *byte*
+            int j = stride * i;
+
+            Vector3 delta;
+
+            // Get a value from B (with wrapping lookup) relative to (x, y)
+            // and divide by 255
+            #define height(DX, DY)  ((int)B[(((DX + x + w) % w) + \
+                                            ((DY + y + h) % h) * w) * stride])
+
+
+            // Sobel filter to compute the normal.  
+            //
+            // Y Filter (X filter is the transpose)
+            //  [ -1 -2 -1 ]
+            //  [  0  0  0 ]
+            //  [  1  2  1 ]
+
+            // Write the Y value directly into the x-component so we don't have
+            // to explicitly compute a cross product at the end.
+            delta.y = -(height(-1, -1) *  1 + height( 0, -1) *  2 + height( 1, -1) *  1 +
+                        height(-1,  1) * -1 + height( 0,  1) * -2 + height( 1,  1) * -1);
+
+            delta.x = -(height(-1, -1) * -1 + height( 1, -1) * 1 + 
+                        height(-1,  0) * -2 + height( 1,  0) * 2 + 
+                        height(-1,  1) * -1 + height( 1,  1) * 1);
+
+            // The scale of each filter row is 4, the filter width is two pixels,
+            // and the "normal" range is 0-255.
+            delta.z = 4 * 2 * (whiteHeightInPixels / 255.0f);
+
+            // Delta is now scaled in pixels; normalize 
+            delta = delta.direction();
+
+            // Copy over the bump value into the alpha channel.
+            float H = B[j] / 255.0;
+
+            if (lowPassBump) {
+                H = (height(-1, -1) + height( 0, -1) + height(1, -1) +
+                        height(-1,  0) + height( 0,  0) + height(1,  0) +
+                        height(-1,  1) + height( 0,  1) + height(1,  1)) / (255.0f * 9.0f);
+            }
+            #undef height
+
+            if (scaleHeightByNz) {
+                // delta.z can't possibly be negative, so we avoid actually
+                // computing the absolute value.
+                H *= delta.z;
+            }
+
+            N[i].a = iRound(H * 255.0);
+
+            // Pack into byte range
+            delta = delta * 127.5 + Vector3(127.5, 127.5, 127.5);
+            N[i].r = iClamp(iRound(delta.x), 0, 255);
+            N[i].g = iClamp(iRound(delta.y), 0, 255);
+            N[i].b = iClamp(iRound(delta.z), 0, 255);
+        }
+    }
+}
+
+
+/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+void GImage::convertToL8() {
+    switch(channels) {
+    case 1:
+        return;
+
+    case 3:
+        {            
+            // Average
+            Color3uint8* src = (Color3uint8*)_byte;
+            _byte = NULL;
+            resize(width, height, 1);
+            for (int i = width * height - 1; i >= 0; --i) {
+                const Color3uint8   s = src[i];
+                uint8&              d = _byte[i]; 
+                d = ((int)s.r + (int)s.g + (int)s.b) / 3;
+            }
+            System::free(src);
+        }
+        break;
+
+    case 4:
+        {            
+            // Average
+            Color4uint8* src = (Color4uint8*)_byte;
+            _byte = NULL;
+            resize(width, height, 1);
+            for (int i = width * height - 1; i >= 0; --i) {
+                const Color4uint8   s = src[i];
+                uint8&              d = _byte[i]; 
+                d = ((int)s.r + (int)s.g + (int)s.b) / 3;
+            }
+            System::free(src);
+        }
+        return;
+
+    default:
+        alwaysAssertM(false, "Bad number of channels in input image");
+    }
+}
+
+
+void GImage::convertToRGBA() {
+    switch(channels) {
+    case 1:
+        {            
+            // Spread
+            uint8* old = _byte;
+            _byte = NULL;
+            resize(width, height, 4);
+            for (int i = width * height - 1; i >= 0; --i) {
+                const uint8  s = old[i];
+                Color4uint8& d = ((Color4uint8*)_byte)[i]; 
+                d.r = d.g = d.b = s;
+                d.a = 255;
+            }
+            System::free(_byte);
+        }
+        break;
+
+    case 3:
+        {            
+            // Add alpha
+            Color3uint8* old = (Color3uint8*)_byte;
+            _byte = NULL;
+            resize(width, height, 4);
+            for (int i = width * height - 1; i >= 0; --i) {
+                const Color3uint8   s = old[i];
+                Color4uint8&        d = ((Color4uint8*)_byte)[i]; 
+                d.r = s.r;
+                d.g = s.g;
+                d.b = s.b;
+                d.a = 255;
+            }
+            System::free(old);
+        }
+        break;
+
+    case 4:
+        // Already RGBA
+        return;
+
+    default:
+        alwaysAssertM(false, "Bad number of channels in input image");
+    }
+}
+
+
+void GImage::convertToRGB() {
+    switch(channels) {
+    case 1:
+        {            
+            // Spread
+            uint8* old = _byte;
+            _byte = NULL;
+            resize(width, height, 3);
+            for (int i = width * height - 1; i >= 0; --i) {
+                const uint8  s = old[i];
+                Color3uint8& d = ((Color3uint8*)_byte)[i]; 
+                d.r = d.g = d.b = s;
+            }
+            System::free(old);
+        }
+        break;
+
+    case 3:
+		return;
+
+    case 4:
+		// Strip alpha
+        {            
+            Color4uint8* old = (Color4uint8*)_byte;
+            _byte = NULL;
+            resize(width, height, 3);
+            for (int i = width * height - 1; i >= 0; --i) {
+                const Color4uint8   s = old[i];
+                Color3uint8&        d = ((Color3uint8*)_byte)[i]; 
+                d.r = s.r;
+                d.g = s.g;
+                d.b = s.b;
+            }
+            System::free(old);
+        }
+        break;
+
+    default:
+        alwaysAssertM(false, "Bad number of channels in input image");
+    }
+}
+
+
+void GImage::R8G8B8_to_Y8U8V8(int width, int height, const uint8* _in, uint8* _out) {
+    const Color3uint8* in = reinterpret_cast<const Color3uint8*>(_in);
+    Color3uint8* out = reinterpret_cast<Color3uint8*>(_out);
+
+    Color3uint8 p;
+    for (int i = width * height - 1; i >= 0; --i) {
+        p.r = iClamp(iRound(in->r *  0.229 + in->g *  0.587 + in->b *  0.114), 0, 255);
+        p.g = iClamp(iRound(in->r * -0.147 + in->g * -0.289 + in->b *  0.436) + 127, 0, 255);
+        p.b = iClamp(iRound(in->r *  0.615 + in->g * -0.515 + in->b * -0.100) + 127, 0, 255);
+        *out = p;
+        ++in;
+        ++out;
+    }
+}
+
+
+
+void GImage::Y8U8V8_to_R8G8B8(int width, int height, const uint8* _in, uint8* _out) {
+    const Color3uint8* in = reinterpret_cast<const Color3uint8*>(_in);
+    Color3uint8* out = reinterpret_cast<Color3uint8*>(_out);
+
+    Color3uint8 p;
+    for (int i = width * height - 1; i >= 0; --i) {
+        p.r = iClamp(iRound(in->r *  1.0753 +                   (in->b - 127) *  1.2256), 0, 255);
+        p.g = iClamp(iRound(in->r *  1.0753 + (in->g - 127) * -0.3946 + (in->b - 127) * -0.4947), 0, 255);
+        p.b = iClamp(iRound(in->r *  1.0753 + (in->g - 127) *  2.0320 + (in->b - 127) *  0.0853), 0, 255);
+        *out = p;
+        ++in;
+        ++out;
+    }
+}
+
+
+void GImage::makeCheckerboard(GImage& im, int checkerSize, const Color4uint8& A, const Color4uint8& B) {
+    for (int y = 0; y < im.height; ++y) {
+        for (int x = 0; x < im.width; ++x) {
+            bool checker = isOdd((x / checkerSize) + (y / checkerSize));
+            const Color4uint8& color = checker ? A : B;
+            for (int c = 0; c < im.channels; ++c) {
+                uint8* v = im.byte() + (x + y * im.width) * im.channels + c;
+                *v = color[c];
+            }
+        }
+    }
+}
+
+}
+