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| -rw-r--r-- | samplecode/SampleWarp.cpp | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/samplecode/SampleWarp.cpp b/samplecode/SampleWarp.cpp new file mode 100644 index 0000000000..5e189099be --- /dev/null +++ b/samplecode/SampleWarp.cpp @@ -0,0 +1,211 @@ +#include "SampleCode.h" +#include "SkView.h" +#include "SkCanvas.h" +#include "SkGradientShader.h" +#include "SkPath.h" +#include "SkRegion.h" +#include "SkShader.h" +#include "SkUtils.h" +#include "SkImageDecoder.h" + +class Mesh { +public: + Mesh(); + ~Mesh(); + + Mesh& operator=(const Mesh& src); + + void init(const SkRect& bounds, int rows, int cols, + const SkRect& texture); + + int rows() const { return fRows; } + int cols() const { return fCols; } + SkPoint& pt(int row, int col) { + return fPts[row * (fRows + 1) + col]; + } + + void draw(SkCanvas*, const SkPaint&); + void drawWireframe(SkCanvas* canvas, const SkPaint& paint); + +private: + int fRows, fCols; + SkPoint* fPts; + SkPoint* fTex; // just points into fPts, not separately allocated + int fCount; + uint16_t* fIndices; + int fIndexCount; +}; + +Mesh::Mesh() : fPts(NULL), fCount(0), fIndices(NULL), fIndexCount(0) {} + +Mesh::~Mesh() { + delete[] fPts; + delete[] fIndices; +} + +Mesh& Mesh::operator=(const Mesh& src) { + delete[] fPts; + delete[] fIndices; + + fRows = src.fRows; + fCols = src.fCols; + + fCount = src.fCount; + fPts = new SkPoint[fCount * 2]; + fTex = fPts + fCount; + memcpy(fPts, src.fPts, fCount * 2 * sizeof(SkPoint)); + + delete[] fIndices; + fIndexCount = src.fIndexCount; + fIndices = new uint16_t[fIndexCount]; + memcpy(fIndices, src.fIndices, fIndexCount * sizeof(uint16_t)); + + return *this; +} + +void Mesh::init(const SkRect& bounds, int rows, int cols, + const SkRect& texture) { + SkASSERT(rows > 0 && cols > 0); + + fRows = rows; + fCols = cols; + + delete[] fPts; + fCount = (rows + 1) * (cols + 1); + fPts = new SkPoint[fCount * 2]; + fTex = fPts + fCount; + + delete[] fIndices; + fIndexCount = rows * cols * 6; + fIndices = new uint16_t[fIndexCount]; + + SkPoint* pts = fPts; + const SkScalar dx = bounds.width() / rows; + const SkScalar dy = bounds.height() / cols; + SkPoint* tex = fTex; + const SkScalar dtx = texture.width() / rows; + const SkScalar dty = texture.height() / cols; + uint16_t* idx = fIndices; + int index = 0; + for (int y = 0; y <= cols; y++) { + for (int x = 0; x <= rows; x++) { + pts->set(bounds.fLeft + x*dx, bounds.fTop + y*dy); + pts += 1; + tex->set(texture.fLeft + x*dtx, texture.fTop + y*dty); + tex += 1; + + if (y < cols && x < rows) { + *idx++ = index; + *idx++ = index + rows + 1; + *idx++ = index + 1; + + *idx++ = index + 1; + *idx++ = index + rows + 1; + *idx++ = index + rows + 2; + + index += 1; + } + } + index += 1; + } +} + +void Mesh::draw(SkCanvas* canvas, const SkPaint& paint) { + canvas->drawVertices(SkCanvas::kTriangles_VertexMode, fCount, + fPts, fTex, NULL, NULL, fIndices, fIndexCount, + paint); +} + +void Mesh::drawWireframe(SkCanvas* canvas, const SkPaint& paint) { + canvas->drawVertices(SkCanvas::kTriangles_VertexMode, fCount, + fPts, NULL, NULL, NULL, fIndices, fIndexCount, + paint); +} + +/////////////////////////////////////////////////////////////////////////////// + +class WarpView : public SkView { + Mesh fMesh, fOrig; + SkBitmap fBitmap; +public: + WarpView() { + SkBitmap bm; + SkImageDecoder::DecodeFile("/skimages/nytimes.png", &bm); + SkIRect subset = { 0, 0, 420, 420 }; + bm.extractSubset(&fBitmap, subset); + + SkRect bounds, texture; + texture.set(0, 0, SkIntToScalar(fBitmap.width()), + SkIntToScalar(fBitmap.height())); + bounds = texture; + +// fMesh.init(bounds, fBitmap.width() / 40, fBitmap.height() / 40, texture); + fMesh.init(bounds, 10, 10, texture); + fOrig = fMesh; + } + +protected: + // overrides from SkEventSink + virtual bool onQuery(SkEvent* evt) { + if (SampleCode::TitleQ(*evt)) { + SampleCode::TitleR(evt, "Warp"); + return true; + } + return this->INHERITED::onQuery(evt); + } + + void warp(const SkPoint& p0, const SkPoint& p1) { + int rows = fMesh.rows(); + int cols = fMesh.cols(); + + const SkVector delta = p1 - p0; + for (int y = 1; y < cols; y++) { + for (int x = 1; x < rows; x++) { + const SkPoint& orig = fOrig.pt(x, y); + SkScalar dist = SkPoint::Distance(p0, orig); + dist += SkIntToScalar(1); + // dist = SkScalarSqrt(dist); + SkScalar dx = SkScalarDiv(delta.fX, dist); + SkScalar dy = SkScalarDiv(delta.fY, dist); + fMesh.pt(x, y).set(orig.fX + dx, orig.fY + dy); +// SkDebugf("[%g %g] -> [%d %d %g] <%g %g>\n", delta.fX, delta.fY, x, y, dist, dx, dy); + } + } + } + + virtual void onDraw(SkCanvas* canvas) { + canvas->drawColor(SK_ColorGRAY); + + SkPaint paint; + paint.setFilterBitmap(true); + paint.setShader(SkShader::CreateBitmapShader(fBitmap, + SkShader::kClamp_TileMode, + SkShader::kClamp_TileMode))->unref(); + fMesh.draw(canvas, paint); + + paint.setShader(NULL); + paint.setColor(SK_ColorRED); + fMesh.draw(canvas, paint); + } + + virtual SkView::Click* onFindClickHandler(SkScalar x, SkScalar y) { + return new Click(this); + } + + virtual bool onClick(Click* click) { + this->warp(click->fOrig, click->fCurr); + this->inval(NULL); + return true; + } + +private: + SkIRect fBase, fRect; + + typedef SkView INHERITED; +}; + +////////////////////////////////////////////////////////////////////////////// + +static SkView* MyFactory() { return new WarpView; } +static SkViewRegister reg(MyFactory); + |