DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (d8847129d134)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335

/*
 * Copyright 2006 The Android Open Source Project
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */


#include "SkNinePatch.h"
#include "SkCanvas.h"
#include "SkShader.h"

static const uint16_t g3x3Indices[] = {
    0, 5, 1,    0, 4, 5,
    1, 6, 2,    1, 5, 6,
    2, 7, 3,    2, 6, 7,

    4, 9, 5,    4, 8, 9,
    5, 10, 6,   5, 9, 10,
    6, 11, 7,   6, 10, 11,

    8, 13, 9,   8, 12, 13,
    9, 14, 10,  9, 13, 14,
    10, 15, 11, 10, 14, 15
};

static int fillIndices(uint16_t indices[], int xCount, int yCount) {
    uint16_t* startIndices = indices;

    int n = 0;
    for (int y = 0; y < yCount; y++) {
        for (int x = 0; x < xCount; x++) {
            *indices++ = n;
            *indices++ = n + xCount + 2;
            *indices++ = n + 1;

            *indices++ = n;
            *indices++ = n + xCount + 1;
            *indices++ = n + xCount + 2;

            n += 1;
        }
        n += 1;
    }
    return static_cast<int>(indices - startIndices);
}

// Computes the delta between vertices along a single axis
static SkScalar computeVertexDelta(bool isStretchyVertex,
                                   SkScalar currentVertex,
                                   SkScalar prevVertex,
                                   SkScalar stretchFactor) {
    // the standard delta between vertices if no stretching is required
    SkScalar delta = currentVertex - prevVertex;

    // if the stretch factor is negative or zero we need to shrink the 9-patch
    // to fit within the target bounds.  This means that we will eliminate all
    // stretchy areas and scale the fixed areas to fit within the target bounds.
    if (stretchFactor <= 0) {
        if (isStretchyVertex)
            delta = 0; // collapse stretchable areas
        else
            delta = SkScalarMul(delta, -stretchFactor); // scale fixed areas
    // if the stretch factor is positive then we use the standard delta for
    // fixed and scale the stretchable areas to fill the target bounds.
    } else if (isStretchyVertex) {
        delta = SkScalarMul(delta, stretchFactor);
    }

    return delta;
}

static void fillRow(SkPoint verts[], SkPoint texs[],
                    const SkScalar vy, const SkScalar ty,
                    const SkRect& bounds, const int32_t xDivs[], int numXDivs,
                    const SkScalar stretchX, int width) {
    SkScalar vx = bounds.fLeft;
    verts->set(vx, vy); verts++;
    texs->set(0, ty); texs++;

    SkScalar prev = 0;
    for (int x = 0; x < numXDivs; x++) {

        const SkScalar tx = SkIntToScalar(xDivs[x]);
        vx += computeVertexDelta(x & 1, tx, prev, stretchX);
        prev = tx;

        verts->set(vx, vy); verts++;
        texs->set(tx, ty); texs++;
    }
    verts->set(bounds.fRight, vy); verts++;
    texs->set(SkIntToScalar(width), ty); texs++;
}

struct Mesh {
    const SkPoint*  fVerts;
    const SkPoint*  fTexs;
    const SkColor*  fColors;
    const uint16_t* fIndices;
};

void SkNinePatch::DrawMesh(SkCanvas* canvas, const SkRect& bounds,
                           const SkBitmap& bitmap,
                           const int32_t xDivs[], int numXDivs,
                           const int32_t yDivs[], int numYDivs,
                           const SkPaint* paint) {
    if (bounds.isEmpty() || bitmap.width() == 0 || bitmap.height() == 0) {
        return;
    }

    // should try a quick-reject test before calling lockPixels
    SkAutoLockPixels alp(bitmap);
    // after the lock, it is valid to check
    if (!bitmap.readyToDraw()) {
        return;
    }

    // check for degenerate divs (just an optimization, not required)
    {
        int i;
        int zeros = 0;
        for (i = 0; i < numYDivs && yDivs[i] == 0; i++) {
            zeros += 1;
        }
        numYDivs -= zeros;
        yDivs += zeros;
        for (i = numYDivs - 1; i >= 0 && yDivs[i] == bitmap.height(); --i) {
            numYDivs -= 1;
        }
    }

    Mesh mesh;

    const int numXStretch = (numXDivs + 1) >> 1;
    const int numYStretch = (numYDivs + 1) >> 1;

    if (numXStretch < 1 && numYStretch < 1) {
        canvas->drawBitmapRect(bitmap, NULL, bounds, paint);
        return;
    }

    if (false) {
        int i;
        for (i = 0; i < numXDivs; i++) {
            SkDebugf("--- xdivs[%d] %d\n", i, xDivs[i]);
        }
        for (i = 0; i < numYDivs; i++) {
            SkDebugf("--- ydivs[%d] %d\n", i, yDivs[i]);
        }
    }

    SkScalar stretchX = 0, stretchY = 0;

    if (numXStretch > 0) {
        int stretchSize = 0;
        for (int i = 1; i < numXDivs; i += 2) {
            stretchSize += xDivs[i] - xDivs[i-1];
        }
        const SkScalar fixed = SkIntToScalar(bitmap.width() - stretchSize);
        if (bounds.width() >= fixed)
            stretchX = (bounds.width() - fixed) / stretchSize;
        else // reuse stretchX, but keep it negative as a signal
            stretchX = SkScalarDiv(-bounds.width(), fixed);
    }

    if (numYStretch > 0) {
        int stretchSize = 0;
        for (int i = 1; i < numYDivs; i += 2) {
            stretchSize += yDivs[i] - yDivs[i-1];
        }
        const SkScalar fixed = SkIntToScalar(bitmap.height() - stretchSize);
        if (bounds.height() >= fixed)
            stretchY = (bounds.height() - fixed) / stretchSize;
        else // reuse stretchX, but keep it negative as a signal
            stretchY = SkScalarDiv(-bounds.height(), fixed);
    }

#if 0
    SkDebugf("---- drawasamesh [%d %d] -> [%g %g] <%d %d> (%g %g)\n",
             bitmap.width(), bitmap.height(),
             SkScalarToFloat(bounds.width()), SkScalarToFloat(bounds.height()),
             numXDivs + 1, numYDivs + 1,
             SkScalarToFloat(stretchX), SkScalarToFloat(stretchY));
#endif

    const int vCount = (numXDivs + 2) * (numYDivs + 2);
    // number of celss * 2 (tris per cell) * 3 (verts per tri)
    const int indexCount = (numXDivs + 1) * (numYDivs + 1) * 2 * 3;
    // allocate 2 times, one for verts, one for texs, plus indices
    SkAutoMalloc storage(vCount * sizeof(SkPoint) * 2 +
                         indexCount * sizeof(uint16_t));
    SkPoint* verts = (SkPoint*)storage.get();
    SkPoint* texs = verts + vCount;
    uint16_t* indices = (uint16_t*)(texs + vCount);

    mesh.fVerts = verts;
    mesh.fTexs = texs;
    mesh.fColors = NULL;
    mesh.fIndices = NULL;

    // we use <= for YDivs, since the prebuild indices work for 3x2 and 3x1 too
    if (numXDivs == 2 && numYDivs <= 2) {
        mesh.fIndices = g3x3Indices;
    } else {
        SkDEBUGCODE(int n =) fillIndices(indices, numXDivs + 1, numYDivs + 1);
        SkASSERT(n == indexCount);
        mesh.fIndices = indices;
    }

    SkScalar vy = bounds.fTop;
    fillRow(verts, texs, vy, 0, bounds, xDivs, numXDivs,
            stretchX, bitmap.width());
    verts += numXDivs + 2;
    texs += numXDivs + 2;
    for (int y = 0; y < numYDivs; y++) {
        const SkScalar ty = SkIntToScalar(yDivs[y]);
        if (stretchY >= 0) {
            if (y & 1) {
                vy += stretchY;
            } else {
                vy += ty;
            }
        } else {    // shrink fixed sections, and collaps stretchy sections
            if (y & 1) {
                ;// do nothing
            } else {
                vy += SkScalarMul(ty, -stretchY);
            }
        }
        fillRow(verts, texs, vy, ty, bounds, xDivs, numXDivs,
                stretchX, bitmap.width());
        verts += numXDivs + 2;
        texs += numXDivs + 2;
    }
    fillRow(verts, texs, bounds.fBottom, SkIntToScalar(bitmap.height()),
            bounds, xDivs, numXDivs, stretchX, bitmap.width());

    SkShader* shader = SkShader::CreateBitmapShader(bitmap,
                                                    SkShader::kClamp_TileMode,
                                                    SkShader::kClamp_TileMode);
    SkPaint p;
    if (paint) {
        p = *paint;
    }
    p.setShader(shader)->unref();
    canvas->drawVertices(SkCanvas::kTriangles_VertexMode, vCount,
                         mesh.fVerts, mesh.fTexs, mesh.fColors, NULL,
                         mesh.fIndices, indexCount, p);
}

///////////////////////////////////////////////////////////////////////////////

static void drawNineViaRects(SkCanvas* canvas, const SkRect& dst,
                             const SkBitmap& bitmap, const SkIRect& margins,
                             const SkPaint* paint) {
    const int32_t srcX[4] = {
        0, margins.fLeft, bitmap.width() - margins.fRight, bitmap.width()
    };
    const int32_t srcY[4] = {
        0, margins.fTop, bitmap.height() - margins.fBottom, bitmap.height()
    };
    SkScalar dstX[4] = {
        dst.fLeft, dst.fLeft + SkIntToScalar(margins.fLeft),
        dst.fRight - SkIntToScalar(margins.fRight), dst.fRight
    };
    SkScalar dstY[4] = {
        dst.fTop, dst.fTop + SkIntToScalar(margins.fTop),
        dst.fBottom - SkIntToScalar(margins.fBottom), dst.fBottom
    };

    if (dstX[1] > dstX[2]) {
        dstX[1] = dstX[0] + (dstX[3] - dstX[0]) * SkIntToScalar(margins.fLeft) /
            (SkIntToScalar(margins.fLeft) + SkIntToScalar(margins.fRight));
        dstX[2] = dstX[1];
    }

    if (dstY[1] > dstY[2]) {
        dstY[1] = dstY[0] + (dstY[3] - dstY[0]) * SkIntToScalar(margins.fTop) /
            (SkIntToScalar(margins.fTop) + SkIntToScalar(margins.fBottom));
        dstY[2] = dstY[1];
    }

    SkIRect s;
    SkRect  d;
    for (int y = 0; y < 3; y++) {
        s.fTop = srcY[y];
        s.fBottom = srcY[y+1];
        d.fTop = dstY[y];
        d.fBottom = dstY[y+1];
        for (int x = 0; x < 3; x++) {
            s.fLeft = srcX[x];
            s.fRight = srcX[x+1];
            d.fLeft = dstX[x];
            d.fRight = dstX[x+1];
            canvas->drawBitmapRect(bitmap, &s, d, paint);
        }
    }
}

void SkNinePatch::DrawNine(SkCanvas* canvas, const SkRect& bounds,
                           const SkBitmap& bitmap, const SkIRect& margins,
                           const SkPaint* paint) {
    /** Our vertices code has numerical precision problems if the transformed
     coordinates land directly on a 1/2 pixel boundary. To work around that
     for now, we only take the vertices case if we are in opengl. Also,
     when not in GL, the vertices impl is slower (more math) than calling
     the viaRects code.
     */
    if (false /* is our canvas backed by a gpu?*/) {
        int32_t xDivs[2];
        int32_t yDivs[2];

        xDivs[0] = margins.fLeft;
        xDivs[1] = bitmap.width() - margins.fRight;
        yDivs[0] = margins.fTop;
        yDivs[1] = bitmap.height() - margins.fBottom;

        if (xDivs[0] > xDivs[1]) {
            xDivs[0] = bitmap.width() * margins.fLeft /
                (margins.fLeft + margins.fRight);
            xDivs[1] = xDivs[0];
        }
        if (yDivs[0] > yDivs[1]) {
            yDivs[0] = bitmap.height() * margins.fTop /
                (margins.fTop + margins.fBottom);
            yDivs[1] = yDivs[0];
        }

        SkNinePatch::DrawMesh(canvas, bounds, bitmap,
                              xDivs, 2, yDivs, 2, paint);
    } else {
        drawNineViaRects(canvas, bounds, bitmap, margins, paint);
    }
}