add gpu backend (not hooked up yet)
git-svn-id: http://skia.googlecode.com/svn/trunk@649 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gpu/src/GrTouchGesture.cpp b/gpu/src/GrTouchGesture.cpp
new file mode 100644
index 0000000..0eaedc7
--- /dev/null
+++ b/gpu/src/GrTouchGesture.cpp
@@ -0,0 +1,243 @@
+#include "GrTouchGesture.h"
+#include "SkMatrix.h"
+#include "SkTime.h"
+
+#include <math.h>
+
+static const SkMSec MAX_DBL_TAP_INTERVAL = 300;
+static const float MAX_DBL_TAP_DISTANCE = 100;
+static const float MAX_JITTER_RADIUS = 2;
+
+// if true, then ignore the touch-move, 'cause its probably just jitter
+static bool close_enough_for_jitter(float x0, float y0, float x1, float y1) {
+ return sk_float_abs(x0 - x1) <= MAX_JITTER_RADIUS &&
+ sk_float_abs(y0 - y1) <= MAX_JITTER_RADIUS;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+GrTouchGesture::GrTouchGesture() {
+ this->reset();
+}
+
+GrTouchGesture::~GrTouchGesture() {
+}
+
+void GrTouchGesture::reset() {
+ fTouches.reset();
+ fState = kEmpty_State;
+ fLocalM.reset();
+ fGlobalM.reset();
+
+ fLastUpT = SkTime::GetMSecs() - 2*MAX_DBL_TAP_INTERVAL;
+ fLastUpP.set(0, 0);
+}
+
+void GrTouchGesture::flushLocalM() {
+ fGlobalM.postConcat(fLocalM);
+ fLocalM.reset();
+}
+
+const SkMatrix& GrTouchGesture::localM() {
+ if (fFlinger.isActive()) {
+ if (!fFlinger.evaluateMatrix(&fLocalM)) {
+ this->flushLocalM();
+ }
+ }
+ return fLocalM;
+}
+
+void GrTouchGesture::appendNewRec(void* owner, float x, float y) {
+ Rec* rec = fTouches.append();
+ rec->fOwner = owner;
+ rec->fStartX = rec->fPrevX = rec->fLastX = x;
+ rec->fStartY = rec->fPrevY = rec->fLastY = y;
+ rec->fLastT = rec->fPrevT = SkTime::GetMSecs();
+}
+
+void GrTouchGesture::touchBegin(void* owner, float x, float y) {
+// GrPrintf("--- %d touchBegin %p %g %g\n", fTouches.count(), owner, x, y);
+
+ int index = this->findRec(owner);
+ if (index >= 0) {
+ this->flushLocalM();
+ fTouches.removeShuffle(index);
+ GrPrintf("---- already exists, removing\n");
+ }
+
+ if (fTouches.count() == 2) {
+ return;
+ }
+
+ this->flushLocalM();
+ fFlinger.stop();
+
+ this->appendNewRec(owner, x, y);
+
+ switch (fTouches.count()) {
+ case 1:
+ fState = kTranslate_State;
+ break;
+ case 2:
+ fState = kZoom_State;
+ break;
+ default:
+ break;
+ }
+}
+
+int GrTouchGesture::findRec(void* owner) const {
+ for (int i = 0; i < fTouches.count(); i++) {
+ if (owner == fTouches[i].fOwner) {
+ return i;
+ }
+ }
+ return -1;
+}
+
+static float center(float pos0, float pos1) {
+ return (pos0 + pos1) * 0.5f;
+}
+
+static const float MAX_ZOOM_SCALE = 4;
+static const float MIN_ZOOM_SCALE = 0.25f;
+
+float GrTouchGesture::limitTotalZoom(float scale) const {
+ // this query works 'cause we know that we're square-scale w/ no skew/rotation
+ const float curr = fGlobalM[0];
+
+ if (scale > 1 && curr * scale > MAX_ZOOM_SCALE) {
+ scale = MAX_ZOOM_SCALE / curr;
+ } else if (scale < 1 && curr * scale < MIN_ZOOM_SCALE) {
+ scale = MIN_ZOOM_SCALE / curr;
+ }
+ return scale;
+}
+
+void GrTouchGesture::touchMoved(void* owner, float x, float y) {
+// GrPrintf("--- %d touchMoved %p %g %g\n", fTouches.count(), owner, x, y);
+
+ GrAssert(kEmpty_State != fState);
+
+ int index = this->findRec(owner);
+ if (index < 0) {
+ // not found, so I guess we should add it...
+ GrPrintf("---- add missing begin\n");
+ this->appendNewRec(owner, x, y);
+ index = fTouches.count() - 1;
+ }
+
+ Rec& rec = fTouches[index];
+
+ // not sure how valuable this is
+ if (fTouches.count() == 2) {
+ if (close_enough_for_jitter(rec.fLastX, rec.fLastY, x, y)) {
+// GrPrintf("--- drop touchMove, withing jitter tolerance %g %g\n", rec.fLastX - x, rec.fLastY - y);
+ return;
+ }
+ }
+
+ rec.fPrevX = rec.fLastX; rec.fLastX = x;
+ rec.fPrevY = rec.fLastY; rec.fLastY = y;
+ rec.fPrevT = rec.fLastT; rec.fLastT = SkTime::GetMSecs();
+
+ switch (fTouches.count()) {
+ case 1: {
+ float dx = rec.fLastX - rec.fStartX;
+ float dy = rec.fLastY - rec.fStartY;
+ dx = (float)sk_float_round2int(dx);
+ dy = (float)sk_float_round2int(dy);
+ fLocalM.setTranslate(dx, dy);
+ } break;
+ case 2: {
+ GrAssert(kZoom_State == fState);
+ const Rec& rec0 = fTouches[0];
+ const Rec& rec1 = fTouches[1];
+
+ float scale = this->computePinch(rec0, rec1);
+ scale = this->limitTotalZoom(scale);
+
+ fLocalM.setTranslate(-center(rec0.fStartX, rec1.fStartX),
+ -center(rec0.fStartY, rec1.fStartY));
+ fLocalM.postScale(scale, scale);
+ fLocalM.postTranslate(center(rec0.fLastX, rec1.fLastX),
+ center(rec0.fLastY, rec1.fLastY));
+ } break;
+ default:
+ break;
+ }
+}
+
+void GrTouchGesture::touchEnd(void* owner) {
+// GrPrintf("--- %d touchEnd %p\n", fTouches.count(), owner);
+
+ int index = this->findRec(owner);
+ if (index < 0) {
+ GrPrintf("--- not found\n");
+ return;
+ }
+
+ const Rec& rec = fTouches[index];
+ if (this->handleDblTap(rec.fLastX, rec.fLastY)) {
+ return;
+ }
+
+ // count() reflects the number before we removed the owner
+ switch (fTouches.count()) {
+ case 1: {
+ this->flushLocalM();
+ float dx = rec.fLastX - rec.fPrevX;
+ float dy = rec.fLastY - rec.fPrevY;
+ float dur = (rec.fLastT - rec.fPrevT) * 0.001f;
+ if (dur > 0) {
+ fFlinger.reset(dx / dur, dy / dur);
+ }
+ fState = kEmpty_State;
+ } break;
+ case 2:
+ this->flushLocalM();
+ GrAssert(kZoom_State == fState);
+ fState = kEmpty_State;
+ break;
+ default:
+ GrAssert(kZoom_State == fState);
+ break;
+ }
+
+ fTouches.removeShuffle(index);
+}
+
+float GrTouchGesture::computePinch(const Rec& rec0, const Rec& rec1) {
+ double dx = rec0.fStartX - rec1.fStartX;
+ double dy = rec0.fStartY - rec1.fStartY;
+ double dist0 = sqrt(dx*dx + dy*dy);
+
+ dx = rec0.fLastX - rec1.fLastX;
+ dy = rec0.fLastY - rec1.fLastY;
+ double dist1 = sqrt(dx*dx + dy*dy);
+
+ double scale = dist1 / dist0;
+ return (float)scale;
+}
+
+bool GrTouchGesture::handleDblTap(float x, float y) {
+ bool found = false;
+ SkMSec now = SkTime::GetMSecs();
+ if (now - fLastUpT <= MAX_DBL_TAP_INTERVAL) {
+ if (SkPoint::Length(fLastUpP.fX - x,
+ fLastUpP.fY - y) <= MAX_DBL_TAP_DISTANCE) {
+ fFlinger.stop();
+ fLocalM.reset();
+ fGlobalM.reset();
+ fTouches.reset();
+ fState = kEmpty_State;
+ found = true;
+ }
+ }
+
+ fLastUpT = now;
+ fLastUpP.set(x, y);
+ return found;
+}
+
+