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Implement new physics model for scroll.

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This commit is contained in:
Jason Sams
2009-09-18 13:55:55 -07:00
parent e82140fe20
commit 86c87ed0a8
2 changed files with 197 additions and 148 deletions
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res/raw/rollo.c
+162 -127
View File
@@ -5,13 +5,82 @@
#define PI 3.14159f
float deceleration;
// Attraction to center values from page edge to page center.
float g_AttractionTable[9];
float g_FrictionTable[9];
float g_PhysicsTableSize;
float g_PosPage;
float g_PosVelocity;
float g_LastPositionX;
int g_LastTouchDown;
float g_DT;
int g_LastTime;
int g_Rendering;
int g_PageCount;
// Drawing constants, should be parameters ======
#define VIEW_ANGLE 1.28700222f
void init() {
deceleration = 0;
g_AttractionTable[0] = 4.5f;
g_AttractionTable[1] = 4.5f;
g_AttractionTable[2] = 5.0f;
g_AttractionTable[3] = 4.0f;
g_AttractionTable[4] = -4.0f;
g_AttractionTable[5] = -5.0f;
g_AttractionTable[6] = -4.5f;
g_AttractionTable[7] = -4.5f;
g_AttractionTable[8] = -4.5f; // dup 7 to avoid a clamp later
g_FrictionTable[0] = 3.5f;
g_FrictionTable[1] = 3.6f;
g_FrictionTable[2] = 3.7f;
g_FrictionTable[3] = 3.8f;
g_FrictionTable[4] = 3.8f;
g_FrictionTable[5] = 3.7f;
g_FrictionTable[6] = 3.6f;
g_FrictionTable[7] = 3.5f;
g_FrictionTable[8] = 3.5f; // dup 7 to avoid a clamp later
g_PhysicsTableSize = 7;
g_PosVelocity = 0;
g_PosPage = 0;
g_LastTouchDown = 0;
g_LastPositionX = 0;
}
void clampPosition() {
if (g_PosPage < 0) {
g_PosPage = 0;
g_PosVelocity = 0;
}
if (g_PosPage > (g_PageCount - 1)) {
g_PosPage = (g_PageCount - 1);
g_PosVelocity = 0;
}
}
void move() {
if (g_LastTouchDown) {
float dx = -(state->newPositionX - g_LastPositionX);
g_PosVelocity = 0;
g_PosPage += dx;
}
g_LastTouchDown = state->newTouchDown;
g_LastPositionX = state->newPositionX;
clampPosition();
}
void fling() {
g_LastTouchDown = 0;
g_PosVelocity = -state->flingVelocityX;
if (g_PosPage <= 0) {
g_PosVelocity = maxf(0, g_PosVelocity);
}
if (g_PosPage > (g_PageCount - 1)) {
g_PosVelocity = minf(0, (g_PageCount - 1) - g_PosPage);
}
}
int g_lastFrameTime = 0;
@@ -41,6 +110,76 @@ modf(float x, float y)
return x-(y*floorf(x/y));
}
void updatePos() {
if (g_LastTouchDown) {
return;
}
//debugF("g_PosPage", g_PosPage);
//debugF(" g_PosVelocity", g_PosVelocity);
float tablePosNorm = fracf(g_PosPage + 0.5f);
float tablePosF = tablePosNorm * g_PhysicsTableSize;
int tablePosI = tablePosF;
float tablePosFrac = tablePosF - tablePosI;
//debugF("tablePosNorm", tablePosNorm);
//debugF("tablePosF", tablePosF);
//debugF("tablePosI", tablePosI);
//debugF("tablePosFrac", tablePosFrac);
float accel = lerpf(g_AttractionTable[tablePosI],
g_AttractionTable[tablePosI + 1],
tablePosFrac) * g_DT;
float friction = lerpf(g_FrictionTable[tablePosI],
g_FrictionTable[tablePosI + 1],
tablePosFrac) * g_DT;
//debugF(" accel", accel);
//debugF(" friction", friction);
g_PosVelocity += accel;
if ((friction > fabsf(g_PosVelocity)) && (friction > fabsf(accel))) {
// Special get back to center and overcome friction physics.
float t = tablePosNorm - 0.5f;
if (fabsf(t) < (friction * g_DT)) {
// really close, just snap
g_PosPage = roundf(g_PosPage);
g_PosVelocity = 0;
} else {
if (t > 0) {
g_PosVelocity = -friction;
} else {
g_PosVelocity = friction;
}
}
} else {
// Normal physics
if (g_PosVelocity > 0) {
g_PosVelocity -= friction;
if (g_PosVelocity < 0) {
g_PosVelocity = 0;
}
} else {
g_PosVelocity += friction;
if (g_PosVelocity > 0) {
g_PosVelocity = 0;
}
}
}
g_PosPage += g_PosVelocity * g_DT;
// Check for out of boundry conditions.
if (g_PosPage < 0 && g_PosVelocity < 0) {
float damp = 1.0 + (g_PosPage * 3);
damp = clampf(damp, 0.f, 0.9f);
g_PosVelocity *= damp;
}
if (g_PosPage > (g_PageCount-1) && g_PosVelocity > 0) {
float damp = 1.0 - ((g_PosPage - g_PageCount + 1) * 3);
damp = clampf(damp, 0.f, 0.9f);
g_PosVelocity *= damp;
}
}
float
far_size(float sizeAt0)
{
@@ -53,6 +192,7 @@ draw_page(int icon, int lastIcon, float centerAngle)
int row;
int col;
//debugF("center angle", centerAngle);
float scale = 1.0f - state->zoom;
float iconTextureWidth = ICON_WIDTH_PX / (float)ICON_TEXTURE_WIDTH_PX;
@@ -142,6 +282,11 @@ main(int launchID)
// Clear to transparent
pfClearColor(0.0f, 0.0f, 0.0f, 0.0f);
int newTime = uptimeMillis();
g_DT = (newTime - g_LastTime) / 1000.f;
g_LastTime = newTime;
//debugF("*** dt ", g_DT);
// If we're not supposed to be showing, don't do anything.
if (!state->visible) {
return 0;
@@ -149,128 +294,13 @@ main(int launchID)
// icons & labels
int iconCount = state->iconCount;
int pageCount = count_pages(iconCount);
g_PageCount = count_pages(iconCount);
float scrollXPx = state->scrollX;
float maxScrollXPx = -(pageCount-1) * SCREEN_WIDTH_PX;
int done = 0;
updatePos(0.1f);
state->readPosX = g_PosPage;
state->readVel = g_PosVelocity;
// Clamp -- because java doesn't know how big the icons are
if (scrollXPx > 0) {
scrollXPx = 0;
}
if (scrollXPx < maxScrollXPx) {
scrollXPx = maxScrollXPx;
}
// If we've been given a velocity, start a fling
float flingVelocityPxMs = state->flingVelocityX;
if (flingVelocityPxMs != 0) {
// how many screens will this velocity do? TODO: use long
// G * ppi * friction // why G? // friction = 0.015
float flingDurationMs;
if (deceleration == 0) {
// On the first frame, calculate which animation we're going to do. If it's
// going to end up less than halfway into a page, we'll bounce back the previous
// page. Otherwise, we'll adjust the deceleration so it just makes it to the
// page boundary.
if (flingVelocityPxMs > 0) {
deceleration = -1000;
} else {
deceleration = 1000;
}
// minimum velocity
if (flingVelocityPxMs < 0) {
if (flingVelocityPxMs > -500) {
flingVelocityPxMs = -500;
}
} else {
if (flingVelocityPxMs < 500) {
flingVelocityPxMs = 500;
}
}
// v' = v + at --> t = -v / a
// x' = x + vt + .5 a t^2
flingDurationMs = - flingVelocityPxMs / deceleration;
float endPos = scrollXPx + (flingVelocityPxMs*flingDurationMs)
+ ((deceleration*flingDurationMs*flingDurationMs)/2);
if (endPos > 0) {
endPos = 0;
}
if (endPos < maxScrollXPx) {
endPos = maxScrollXPx;
}
float scrollOnPage = modf(endPos, SCREEN_WIDTH_PX);
int endPage = -endPos/SCREEN_WIDTH_PX;
if (flingVelocityPxMs < 0) {
if (scrollOnPage < (SCREEN_WIDTH_PX/2)) {
// adjust the deceleration so we align on the page boundary
// a = 2(x-x0-v0t)/t^2
endPos = -(endPage+1) * SCREEN_WIDTH_PX;
debugI32("endPos case 1", endPos);
} else {
// TODO: bounce
endPos = -(endPage+1) * SCREEN_WIDTH_PX;
debugI32("endPos case 2", endPos);
}
} else {
if (scrollOnPage >= (SCREEN_WIDTH_PX/2)) {
// adjust the deceleration so we align on the page boundary
endPos = -endPage * SCREEN_WIDTH_PX;
debugI32("endPos case 3", endPos);
} else {
// TODO: bounce
endPos = -endPage * SCREEN_WIDTH_PX;
debugI32("endPos case 4", endPos);
}
}
// v = v0 + at --> (v - v0) / t
deceleration = 2*(endPos-scrollXPx-(flingVelocityPxMs*flingDurationMs))
/ (flingDurationMs*flingDurationMs);
endPos = scrollXPx + (flingVelocityPxMs*flingDurationMs)
+ ((deceleration*flingDurationMs*flingDurationMs)/2);
state->flingDuration = flingDurationMs;
state->flingEndPos = endPos;
} else {
flingDurationMs = state->flingDuration;
}
// adjust the deceleration so we always hit a page boundary
int now = uptimeMillis();
float elapsedTime = (now - state->flingTimeMs) / 1000.0f;
int animEndTime = -flingVelocityPxMs / deceleration;
int flingOffsetPx = (flingVelocityPxMs * elapsedTime)
+ (deceleration * elapsedTime * elapsedTime / 2.0f);
scrollXPx += flingOffsetPx;
if (elapsedTime > flingDurationMs) {
scrollXPx = state->flingEndPos;
done = 1;
}
} else {
done = 1;
}
// Clamp
if (scrollXPx > 0) {
scrollXPx = 0;
}
if (scrollXPx < maxScrollXPx) {
scrollXPx = maxScrollXPx;
}
state->currentScrollX = scrollXPx;
if (done) {
state->scrollX = scrollXPx;
state->flingVelocityX = 0;
deceleration = 0.f;
}
//debugF(" draw g_PosPage", g_PosPage);
// Draw the icons ========================================
bindProgramVertex(NAMED_PV);
@@ -282,9 +312,8 @@ main(int launchID)
int lastIcon = iconCount-1;
float currentPage = -scrollXPx / (float)SCREEN_WIDTH_PX;
int page = currentPage;
float currentPagePosition = currentPage - page;
int page = g_PosPage;
float currentPagePosition = g_PosPage - page;
int iconsPerPage = COLUMNS_PER_PAGE * ROWS_PER_PAGE;
int icon = clamp(iconsPerPage * page, 0, lastIcon);
@@ -292,6 +321,7 @@ main(int launchID)
draw_page(icon, lastIcon, -VIEW_ANGLE*currentPagePosition);
draw_page(icon+iconsPerPage, lastIcon, (-VIEW_ANGLE*currentPagePosition)+VIEW_ANGLE);
// Draw the border lines for debugging ========================================
/*
bindProgramVertex(NAMED_PVOrtho);
@@ -320,8 +350,13 @@ main(int launchID)
drawRect(handleLeft, handleTop, handleLeft+handleWidth, handleTop+handleHeight, 0.0f);
*/
print_frame_rate();
//print_frame_rate();
return !done;
// Bug workaround where the last frame is not always displayed
// So we render the last frame twice.
int rendering = g_Rendering;
g_Rendering = (g_PosVelocity != 0) || fracf(g_PosPage);
rendering |= g_Rendering;
return rendering;
}
src/com/android/launcher2/AllAppsView.java
+35 -21
View File
@@ -85,11 +85,11 @@ public class AllAppsView extends RSSurfaceView
private int mPageCount;
private boolean mStartedScrolling;
private VelocityTracker mVelocity;
private int mLastScrollX;
private int mLastMotionX;
private int mMotionDownRawX;
private int mMotionDownRawY;
private int mScrollHandleTop;
private long mTouchTime;
static class Defines {
private static float farSize(float sizeAt0) {
@@ -191,16 +191,17 @@ public class AllAppsView extends RSSurfaceView
mMotionDownRawY = (int)ev.getRawY();
mLastMotionX = x;
mRollo.mState.read();
mRollo.mState.startScrollX = mRollo.mState.scrollX = mLastScrollX
= mRollo.mState.currentScrollX;
if (mRollo.mState.flingVelocityX != 0) {
mRollo.mState.newPositionX = ev.getRawX() / Defines.SCREEN_WIDTH_PX;
mRollo.mState.newTouchDown = 1;
if (mRollo.mState.readVel != 0) {
mRollo.clearSelectedIcon();
} else {
mRollo.selectIcon(x, (int)ev.getY(), mRollo.mState.startScrollX,
(-mRollo.mState.startScrollX / Defines.SCREEN_WIDTH_PX));
mRollo.selectIcon(x, (int)ev.getY(), mRollo.mState.readPosX);
}
mRollo.mState.flingVelocityX = 0;
mRollo.mState.save();
mRollo.mInvokeMove.execute();
mVelocity = VelocityTracker.obtain();
mVelocity.addMovement(ev);
mStartedScrolling = false;
@@ -212,25 +213,31 @@ public class AllAppsView extends RSSurfaceView
// don't update mLastMotionX so slop is right and when we do start scrolling
// below, we get the right delta.
} else {
mRollo.mState.newPositionX = ev.getRawX() / Defines.SCREEN_WIDTH_PX;
mRollo.mState.newTouchDown = 1;
mRollo.mInvokeMove.execute();
mStartedScrolling = true;
mRollo.clearSelectedIcon();
deltaX = x - mLastMotionX;
mVelocity.addMovement(ev);
mRollo.mState.currentScrollX = mLastScrollX;
mLastScrollX += deltaX;
mRollo.mState.scrollX = mLastScrollX;
mRollo.mState.save();
mLastMotionX = x;
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
mRollo.mState.newPositionX = ev.getRawX() / Defines.SCREEN_WIDTH_PX;
mRollo.mState.newTouchDown = 0;
mVelocity.computeCurrentVelocity(1000 /* px/sec */,
mConfig.getScaledMaximumFlingVelocity());
mRollo.mState.flingTimeMs = (int)SystemClock.uptimeMillis(); // TODO: use long
mRollo.mState.flingVelocityX = (int)mVelocity.getXVelocity();
mRollo.mState.flingVelocityX = mVelocity.getXVelocity() / Defines.SCREEN_WIDTH_PX;
mRollo.clearSelectedIcon();
mRollo.mState.save();
mRollo.mInvokeFling.execute();
mLastMotionX = -10000;
mVelocity.recycle();
mVelocity = null;
@@ -354,6 +361,10 @@ public class AllAppsView extends RSSurfaceView
private Resources mRes;
private Script mScript;
private Script.Invokable mInvokeMove;
private Script.Invokable mInvokeFling;
private Sampler mSampler;
private Sampler mSamplerText;
private ProgramStore mPSBackground;
@@ -417,14 +428,13 @@ public class AllAppsView extends RSSurfaceView
}
class State extends BaseAlloc {
public float newPositionX;
public int newTouchDown;
public float readPosX;
public float readVel;
public float flingVelocityX;
public int iconCount;
public int scrollX;
public int flingTimeMs;
public float flingVelocityX;
public int currentScrollX;
public int flingDuration;
public int flingEndPos;
public int startScrollX;
public int selectedIconIndex = -1;
public int selectedIconTexture;
public int visible;
@@ -564,6 +574,8 @@ public class AllAppsView extends RSSurfaceView
sb.addDefines(Defines.class);
sb.setType(mParams.mType, "params", Defines.ALLOC_PARAMS);
sb.setType(mState.mType, "state", Defines.ALLOC_STATE);
mInvokeMove = sb.addInvokable("move");
mInvokeFling = sb.addInvokable("fling");
mScript = sb.create();
mScript.setClearColor(0.0f, 0.0f, 0.0f, 0.0f);
@@ -653,7 +665,9 @@ public class AllAppsView extends RSSurfaceView
mAllocTouchXBorders.data(mTouchXBorders);
}
int chooseTappedIcon(int x, int y, int scrollX, int currentPage) {
int chooseTappedIcon(int x, int y, float page) {
int currentPage = (int)page;
int col = -1;
int row = -1;
@@ -681,8 +695,8 @@ public class AllAppsView extends RSSurfaceView
/**
* You need to call save() on mState on your own after calling this.
*/
void selectIcon(int x, int y, int scrollX, int currentPage) {
int index = chooseTappedIcon(x, y, scrollX, currentPage);
void selectIcon(int x, int y, float pos) {
int index = chooseTappedIcon(x, y, pos);
selectIcon(index);
}