| /* |
| ** Copyright 2006, The Android Open Source Project |
| ** |
| ** Licensed under the Apache License, Version 2.0 (the "License"); |
| ** you may not use this file except in compliance with the License. |
| ** You may obtain a copy of the License at |
| ** |
| ** http://www.apache.org/licenses/LICENSE-2.0 |
| ** |
| ** Unless required by applicable law or agreed to in writing, software |
| ** distributed under the License is distributed on an "AS IS" BASIS, |
| ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| ** See the License for the specific language governing permissions and |
| ** limitations under the License. |
| */ |
| |
| #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 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; |
| |
| SkScalar prev = 0; |
| for (int y = 0; y < numYDivs; y++) { |
| const SkScalar ty = SkIntToScalar(yDivs[y]); |
| vy += computeVertexDelta(y & 1, ty, prev, stretchY); |
| prev = ty; |
| |
| 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); |
| } |
| } |