Changeset 47529 in webkit

Timestamp:

Aug 19, 2009 3:33:54 PM (15 years ago)

Author:

eric@webkit.org

Message:

2009-08-19 Dirk Schulze <​krit@webkit.org>

Reviewed by Oliver Hunt.

SVG feComponentTransfer needs to be implemented
​https://bugs.webkit.org/show_bug.cgi?id=27768

Implementation of SVG Filter feComponentTransfer.

There is already a test case
Test: svg/W3C-SVG-1.1/filters-comptran-01-b.svg

• platform/graphics/filters/FEComponentTransfer.cpp: (WebCore::identity): (WebCore::table): (WebCore::discrete): (WebCore::linear): (WebCore::gamma): (WebCore::FEComponentTransfer::apply):

Location:

trunk/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/graphics/filters/FEComponentTransfer.cpp (modified) (3 diffs)

trunk/WebCore/ChangeLog

@@ +1 @@
+2009-08-19  Dirk Schulze  <krit@webkit.org>
+
+        Reviewed by Oliver Hunt.
+
+        SVG feComponentTransfer needs to be implemented
+        [https://bugs.webkit.org/show_bug.cgi?id=27768]
+
+        Implementation of SVG Filter feComponentTransfer.
+
+        There is already a test case
+        Test: svg/W3C-SVG-1.1/filters-comptran-01-b.svg
+
+        * platform/graphics/filters/FEComponentTransfer.cpp:
+        (WebCore::identity):
+        (WebCore::table):
+        (WebCore::discrete):
+        (WebCore::linear):
+        (WebCore::gamma):
+        (WebCore::FEComponentTransfer::apply):
+
 2009-08-19  Dan Bernstein  <mitz@apple.com>
 

trunk/WebCore/platform/graphics/filters/FEComponentTransfer.cpp

@@ -3 +3 @@
                   2004, 2005 Rob Buis <buis@kde.org>
                   2005 Eric Seidel <eric@webkit.org>
+                  2009 Dirk Schulze <krit@webkit.org>
 
     This library is free software; you can redistribute it and/or
@@ -25 +26 @@
 #include "FEComponentTransfer.h"
 
+#include "CanvasPixelArray.h"
 #include "Filter.h"
+#include "GraphicsContext.h"
+#include "ImageData.h"
+#include <math.h>
 
 namespace WebCore {
+
+typedef void (*TransferType)(unsigned char*, const ComponentTransferFunction&);
 
 FEComponentTransfer::FEComponentTransfer(FilterEffect* in, const ComponentTransferFunction& redFunc, 
@@ -86 +93 @@
 }
 
-void FEComponentTransfer::apply(Filter*)
+void identity(unsigned char*, const ComponentTransferFunction&)
 {
+}
+
+void table(unsigned char* values, const ComponentTransferFunction& transferFunction)
+{
+    const Vector<float>& tableValues = transferFunction.tableValues;
+    unsigned n = tableValues.size();
+    if (n < 1)
+        return;            
+    for (unsigned i = 0; i < 256; ++i) {
+        double c = i / 255.0;                
+        unsigned k = static_cast<unsigned>(c * (n - 1));
+        double v1 = tableValues[k];
+        double v2 = tableValues[std::min((k + 1), (n - 1))];
+        double val = 255.0 * (v1 + (c * (n - 1) - k) * (v2 - v1));
+        val = std::max(0.0, std::min(255.0, val));
+        values[i] = static_cast<unsigned char>(val);
+    }
+}
+
+void discrete(unsigned char* values, const ComponentTransferFunction& transferFunction)
+{
+    const Vector<float>& tableValues = transferFunction.tableValues;
+    unsigned n = tableValues.size();
+    if (n < 1)
+        return;
+    for (unsigned i = 0; i < 256; ++i) {
+        unsigned k = static_cast<unsigned>((i * n) / 255.0);
+        k = std::min(k, n - 1);
+        double val = 255 * tableValues[k];
+        val = std::max(0.0, std::min(255.0, val));
+        values[i] = static_cast<unsigned char>(val);
+    }
+}
+
+void linear(unsigned char* values, const ComponentTransferFunction& transferFunction)
+{
+    for (unsigned i = 0; i < 256; ++i) {
+        double val = transferFunction.slope * i + 255 * transferFunction.intercept;
+        val = std::max(0.0, std::min(255.0, val));
+        values[i] = static_cast<unsigned char>(val);
+    }
+}
+
+void gamma(unsigned char* values, const ComponentTransferFunction& transferFunction)
+{
+    for (unsigned i = 0; i < 256; ++i) {
+        double val = 255.0 * (transferFunction.amplitude * pow((i / 255.0), transferFunction.exponent) + transferFunction.offset);
+        val = std::max(0.0, std::min(255.0, val));
+        values[i] = static_cast<unsigned char>(val);
+    }
+}
+
+void FEComponentTransfer::apply(Filter* filter)
+{
+    m_in->apply(filter);
+    if (!m_in->resultImage())
+        return;
+
+    if (!getEffectContext())
+        return;
+
+    unsigned char rValues[256], gValues[256], bValues[256], aValues[256];
+    for (unsigned i = 0; i < 256; ++i)
+        rValues[i] = gValues[i] = bValues[i] = aValues[i] = i;
+    unsigned char* tables[] = { rValues, gValues, bValues, aValues };
+    ComponentTransferFunction transferFunction[] = {m_redFunc, m_greenFunc, m_blueFunc, m_alphaFunc};
+    TransferType callEffect[] = {identity, identity, table, discrete, linear, gamma};
+
+    for (unsigned channel = 0; channel < 4; channel++)
+        (*callEffect[transferFunction[channel].type])(tables[channel], transferFunction[channel]);
+
+    IntRect drawingRect = calculateDrawingIntRect(m_in->subRegion());
+    RefPtr<ImageData> imageData(m_in->resultImage()->getUnmultipliedImageData(drawingRect));
+    CanvasPixelArray* srcPixelArray(imageData->data());
+
+    for (unsigned pixelOffset = 0; pixelOffset < srcPixelArray->length(); pixelOffset += 4) {
+        for (unsigned channel = 0; channel < 4; ++channel) {
+            unsigned char c = srcPixelArray->get(pixelOffset + channel);
+            imageData->data()->set(pixelOffset + channel, tables[channel][c]);
+        }
+    }
+
+    resultImage()->putUnmultipliedImageData(imageData.get(), IntRect(IntPoint(), resultImage()->size()), IntPoint());
 }