SkLatticeIter.cpp File Reference

#include "src/core/SkLatticeIter.h"
#include "include/core/SkMatrix.h"
#include "include/core/SkRect.h"
#include "include/private/base/SkAssert.h"
#include "include/private/base/SkTo.h"
#include <cstdint>

Go to the source code of this file.

Functions
static bool	valid_divs (const int *divs, int count, int start, int end)
static int	count_scalable_pixels (const int32_t *divs, int numDivs, bool firstIsScalable, int start, int end)
static void	set_points (float *dst, int *src, const int *divs, int divCount, int srcFixed, int srcScalable, int srcStart, int srcEnd, float dstStart, float dstEnd, bool isScalable)

Function Documentation

count_scalable_pixels()

static int count_scalable_pixels ( const int32_t *  divs, int  numDivs, bool  firstIsScalable, int  start, int  end  )

static

Count the number of pixels that are in "scalable" patches.

Definition at line 55 of file SkLatticeIter.cpp.

                                                     {
    if (0 == numDivs) {
        return firstIsScalable ? end - start : 0;
    }
 
    int i;
    int count;
    if (firstIsScalable) {
        count = divs[0] - start;
        i = 1;
    } else {
        count = 0;
        i = 0;
    }
 
    for (; i < numDivs; i += 2) {
        // Alternatively, we could use |top| and |bottom| as variable names, instead of
        // |left| and |right|.
        int left = divs[i];
        int right = (i + 1 < numDivs) ? divs[i + 1] : end;
        count += right - left;
    }
 
    return count;
}

set_points()

static void set_points ( float *  dst, int *  src, const int *  divs, int  divCount, int  srcFixed, int  srcScalable, int  srcStart, int  srcEnd, float  dstStart, float  dstEnd, bool  isScalable  )

static

Set points for the src and dst rects on subsequent draw calls.

Definition at line 85 of file SkLatticeIter.cpp.

                                        {
    float dstLen = dstEnd - dstStart;
    float scale;
    if (srcFixed <= dstLen) {
        // This is the "normal" case, where we scale the "scalable" patches and leave
        // the other patches fixed.
        scale = (dstLen - ((float) srcFixed)) / ((float) srcScalable);
    } else {
        // In this case, we eliminate the "scalable" patches and scale the "fixed" patches.
        scale = dstLen / ((float) srcFixed);
    }
 
    src[0] = srcStart;
    dst[0] = dstStart;
    for (int i = 0; i < divCount; i++) {
        src[i + 1] = divs[i];
        int srcDelta = src[i + 1] - src[i];
        float dstDelta;
        if (srcFixed <= dstLen) {
            dstDelta = isScalable ? scale * srcDelta : srcDelta;
        } else {
            dstDelta = isScalable ? 0.0f : scale * srcDelta;
        }
        dst[i + 1] = dst[i] + dstDelta;
 
        // Alternate between "scalable" and "fixed" patches.
        isScalable = !isScalable;
    }
 
    src[divCount + 1] = srcEnd;
    dst[divCount + 1] = dstEnd;
}

valid_divs()

static bool valid_divs ( const int *  divs, int  count, int  start, int  end  )

static

Divs must be in increasing order with no duplicates.

Definition at line 20 of file SkLatticeIter.cpp.

                                                                       {
    int prev = start - 1;
    for (int i = 0; i < count; i++) {
        if (prev >= divs[i] || divs[i] >= end) {
            return false;
        }
        prev = divs[i];
    }
 
    return true;
}