ImageFilterDAGSlide.cpp File Reference

#include "include/core/SkCanvas.h"
#include "include/core/SkColor.h"
#include "include/core/SkColorFilter.h"
#include "include/core/SkFont.h"
#include "include/core/SkImage.h"
#include "include/core/SkImageFilter.h"
#include "include/core/SkImageInfo.h"
#include "include/core/SkPaint.h"
#include "include/core/SkPathEffect.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRect.h"
#include "include/core/SkSurface.h"
#include "include/effects/SkDashPathEffect.h"
#include "include/effects/SkGradientShader.h"
#include "include/effects/SkImageFilters.h"
#include "src/core/SkImageFilter_Base.h"
#include "src/core/SkSpecialImage.h"
#include "tools/ToolUtils.h"
#include "tools/fonts/FontToolUtils.h"
#include "tools/viewer/Slide.h"

Go to the source code of this file.

Classes
class	ImageFilterDAGSlide

Functions
static FilterNode	build_dag (const SkMatrix &ctm, const SkRect &rect, const SkImageFilter *rootFilter)
static void	draw_node (SkCanvas *canvas, const FilterNode &node)
static float	print_matrix (SkCanvas *canvas, const char *prefix, const SkMatrix &matrix, float x, float y, const SkFont &font, const SkPaint &paint)
static float	print_size (SkCanvas *canvas, const char *prefix, const SkIRect &rect, float x, float y, const SkFont &font, const SkPaint &paint)
static float	print_info (SkCanvas *canvas, const FilterNode &node)
static float	draw_dag (SkCanvas *canvas, SkSurface *nodeSurface, const FilterNode &node)
static void	draw_dag (SkCanvas *canvas, SkImageFilter *filter, const SkRect &rect, const SkISize &surfaceSize)

Variables
static constexpr float	kLineHeight = 16.f
static constexpr float	kLineInset = 8.f

Function Documentation

build_dag()

static FilterNode build_dag ( const SkMatrix &  ctm, const SkRect &  rect, const SkImageFilter *  rootFilter  )

static

Definition at line 123 of file ImageFilterDAGSlide.cpp.

                                                             {
    // Emulate SkCanvas::internalSaveLayer's decomposition of the CTM.
    skif::ParameterSpace<SkRect> content(rect);
    skif::ParameterSpace<SkPoint> center({rect.centerX(), rect.centerY()});
    skif::Mapping mapping;
    SkAssertResult(mapping.decomposeCTM(ctm, rootFilter, center));
    return FilterNode(rootFilter, mapping, content, 0);
}

draw_dag() [1/2]

static void draw_dag ( SkCanvas *  canvas, SkImageFilter *  filter, const SkRect &  rect, const SkISize &  surfaceSize  )

static

Definition at line 293 of file ImageFilterDAGSlide.cpp.

                                                                     {
    // Get the current CTM, which includes all the viewer's UI modifications, which we want to
    // pass into our mock canvases for each DAG node.
    SkMatrix ctm = canvas->getTotalMatrix();
 
    canvas->save();
    // Reset the matrix so that the DAG layout and instructional text is fixed to the window.
    canvas->resetMatrix();
 
    // Process the image filter DAG to display intermediate results later on, which will apply the
    // provided CTM during draw_node calls.
    FilterNode dag = build_dag(ctm, rect, filter);
 
    sk_sp<SkSurface> nodeSurface =
            canvas->makeSurface(canvas->imageInfo().makeDimensions(surfaceSize));
    draw_dag(canvas, nodeSurface.get(), dag);
 
    canvas->restore();
}

draw_dag() [2/2]

static float draw_dag ( SkCanvas *  canvas, SkSurface *  nodeSurface, const FilterNode &  node  )

static

Definition at line 249 of file ImageFilterDAGSlide.cpp.

                                                                                        {
    // First capture the results of the node, into nodeSurface
    draw_node(nodeSurface->getCanvas(), node);
    sk_sp<SkImage> nodeResults = nodeSurface->makeImageSnapshot();
 
    // Fill in background of the filter node with a checkerboard
    canvas->save();
    canvas->clipRect(SkRect::MakeWH(nodeResults->width(), nodeResults->height()));
    ToolUtils::draw_checkerboard(canvas, SK_ColorGRAY, SK_ColorLTGRAY, 10);
    canvas->restore();
 
    // Display filtered results in current canvas' location (assumed CTM is set for this node)
    canvas->drawImage(nodeResults, 0, 0);
 
    SkPaint line;
    line.setAntiAlias(true);
    line.setStyle(SkPaint::kStroke_Style);
    line.setStrokeWidth(3.f);
 
    // Text info
    canvas->save();
    canvas->translate(0, nodeResults->height());
    float textHeight = print_info(canvas, node);
    canvas->restore();
 
    // Border around filtered results + text info
    canvas->drawRect(SkRect::MakeWH(nodeResults->width(), nodeResults->height() + textHeight),
                     line);
 
    static const float kPad = 20.f;
    float x = nodeResults->width() + kPad;
    float y = 0;
    for (size_t i = 0; i < node.fInputNodes.size(); ++i) {
        // Line connecting this node to its child
        canvas->drawLine(nodeResults->width(), 0.5f * nodeResults->height(), // right of node
                         x, y + 0.5f * nodeResults->height(), line);         // left of child
        canvas->save();
        canvas->translate(x, y);
        y += draw_dag(canvas, nodeSurface, node.fInputNodes[i]);
        canvas->restore();
    }
    return std::max(y, nodeResults->height() + textHeight + kPad);
}

draw_node()

static void draw_node ( SkCanvas *  canvas, const FilterNode &  node  )

static

Definition at line 133 of file ImageFilterDAGSlide.cpp.

                                                                {
    canvas->clear(SK_ColorTRANSPARENT);
 
    SkPaint filterPaint;
    filterPaint.setImageFilter(node.fFilter);
 
    SkRect content = SkRect(node.fContent);
    SkPaint paint;
    static const SkColor kColors[2] = {SK_ColorGREEN, SK_ColorWHITE};
    SkPoint points[2] = { {content.fLeft + 15.f, content.fTop + 15.f},
                          {content.fRight - 15.f, content.fBottom - 15.f} };
    paint.setShader(SkGradientShader::MakeLinear(points, kColors, nullptr, std::size(kColors),
                                                 SkTileMode::kRepeat));
 
    SkPaint line;
    line.setStrokeWidth(0.f);
    line.setStyle(SkPaint::kStroke_Style);
 
    canvas->save();
    canvas->concat(node.fMapping.layerToDevice());
    canvas->save();
    canvas->concat(node.fMapping.layerMatrix());
 
    canvas->saveLayer(&content, &filterPaint);
    canvas->drawRect(content, paint);
    canvas->restore(); // Completes the image filter
 
    // Draw content-rect bounds
    line.setColor(SK_ColorBLACK);
    canvas->drawRect(content, line);
 
    // Bounding boxes have all been mapped by the layer matrix from local to layer space, so undo
    // the layer matrix, leaving just the device matrix.
    canvas->restore();
 
    // The hinted bounds of the layer saved for the filtering
    line.setColor(SK_ColorRED);
    canvas->drawRect(SkRect::Make(SkIRect(node.fHintedLayerBounds)).makeOutset(3.f, 3.f), line);
    // The bounds of the layer if there was no local content hint
    line.setColor(SK_ColorGREEN);
    canvas->drawRect(SkRect::Make(SkIRect(node.fUnhintedLayerBounds)).makeOutset(2.f, 2.f), line);
 
    // The output bounds in layer space
    line.setColor(SK_ColorBLUE);
    canvas->drawRect(SkRect::Make(SkIRect(node.fOutputBounds)).makeOutset(1.f, 1.f), line);
    // Device-space bounding box of the output bounds (e.g. what legacy DAG manipulation via
    // MatrixTransform would produce).
    static const SkScalar kDashParams[] = {6.f, 12.f};
    line.setPathEffect(SkDashPathEffect::Make(kDashParams, 2, 0.f));
    SkRect devOutputBounds = SkRect::Make(SkIRect(node.fMapping.layerToDevice(node.fOutputBounds)));
    canvas->restore(); // undoes device matrix
    canvas->drawRect(devOutputBounds, line);
}

print_info()

static float print_info ( SkCanvas *  canvas, const FilterNode &  node  )

static

Definition at line 214 of file ImageFilterDAGSlide.cpp.

                                                                  {
    SkFont font(ToolUtils::DefaultTypeface(), 12);
    SkPaint text;
    text.setAntiAlias(true);
 
    float y = kLineHeight;
    if (node.fFilter) {
        canvas->drawString(node.fFilter->getTypeName(), kLineInset, y, font, text);
        y += kLineHeight;
        if (node.fDepth == 0) {
            // The mapping is the same for all nodes, so only print at the root
            y = print_matrix(canvas, "Param->Layer", node.fMapping.layerMatrix(),
                        kLineInset, y, font, text);
            y = print_matrix(canvas,
                             "Layer->Device",
                             node.fMapping.layerToDevice(),
                             kLineInset,
                             y,
                             font,
                             text);
        }
 
        y = print_size(canvas, "Layer Size", SkIRect(node.fUnhintedLayerBounds),
                       kLineInset, y, font, text);
        y = print_size(canvas, "Layer Size (hinted)", SkIRect(node.fHintedLayerBounds),
                       kLineInset, y, font, text);
    } else {
        canvas->drawString("Source Input", kLineInset, y, font, text);
        y += kLineHeight;
    }
 
    return y;
}

print_matrix()

static float print_matrix ( SkCanvas *  canvas, const char *  prefix, const SkMatrix &  matrix, float  x, float  y, const SkFont &  font, const SkPaint &  paint  )

static

Definition at line 190 of file ImageFilterDAGSlide.cpp.

                                                                                     {
    canvas->drawString(prefix, x, y, font, paint);
    y += kLineHeight;
    for (int i = 0; i < 3; ++i) {
        SkString row;
        row.appendf("[%.2f %.2f %.2f]",
                    matrix.get(i * 3), matrix.get(i * 3 + 1), matrix.get(i * 3 + 2));
        canvas->drawString(row, x, y, font, paint);
        y += kLineHeight;
    }
    return y;
}

print_size()

static float print_size ( SkCanvas *  canvas, const char *  prefix, const SkIRect &  rect, float  x, float  y, const SkFont &  font, const SkPaint &  paint  )

static

Definition at line 204 of file ImageFilterDAGSlide.cpp.

                                                                                   {
    canvas->drawString(prefix, x, y, font, paint);
    y += kLineHeight;
    SkString sz;
    sz.appendf("%d x %d", rect.width(), rect.height());
    canvas->drawString(sz, x, y, font, paint);
    return y + kLineHeight;
}

Variable Documentation

kLineHeight

constexpr float kLineHeight = 16.f

staticconstexpr

Definition at line 187 of file ImageFilterDAGSlide.cpp.

kLineInset

constexpr float kLineInset = 8.f

staticconstexpr

Definition at line 188 of file ImageFilterDAGSlide.cpp.