mirror of
https://gitlab.winehq.org/wine/wine-gecko.git
synced 2024-09-13 09:24:08 -07:00
750 lines
42 KiB
Java
750 lines
42 KiB
Java
/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
|
|
* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
|
|
* You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
package org.mozilla.gecko.gfx;
|
|
|
|
import java.util.Map;
|
|
import android.graphics.PointF;
|
|
import android.graphics.RectF;
|
|
import android.util.FloatMath;
|
|
import android.util.Log;
|
|
import org.json.JSONArray;
|
|
import org.mozilla.gecko.FloatUtils;
|
|
import org.mozilla.gecko.GeckoAppShell;
|
|
|
|
final class DisplayPortCalculator {
|
|
private static final String LOGTAG = "GeckoDisplayPortCalculator";
|
|
private static final PointF ZERO_VELOCITY = new PointF(0, 0);
|
|
|
|
// Keep this in sync with the TILEDLAYERBUFFER_TILE_SIZE defined in gfx/layers/TiledLayerBuffer.h
|
|
private static final int TILE_SIZE = 256;
|
|
|
|
private static final String PREF_DISPLAYPORT_STRATEGY = "gfx.displayport.strategy";
|
|
private static final String PREF_DISPLAYPORT_FM_MULTIPLIER = "gfx.displayport.strategy_fm.multiplier";
|
|
private static final String PREF_DISPLAYPORT_FM_DANGER_X = "gfx.displayport.strategy_fm.danger_x";
|
|
private static final String PREF_DISPLAYPORT_FM_DANGER_Y = "gfx.displayport.strategy_fm.danger_y";
|
|
private static final String PREF_DISPLAYPORT_VB_MULTIPLIER = "gfx.displayport.strategy_vb.multiplier";
|
|
private static final String PREF_DISPLAYPORT_VB_VELOCITY_THRESHOLD = "gfx.displayport.strategy_vb.threshold";
|
|
private static final String PREF_DISPLAYPORT_VB_REVERSE_BUFFER = "gfx.displayport.strategy_vb.reverse_buffer";
|
|
private static final String PREF_DISPLAYPORT_VB_DANGER_X_BASE = "gfx.displayport.strategy_vb.danger_x_base";
|
|
private static final String PREF_DISPLAYPORT_VB_DANGER_Y_BASE = "gfx.displayport.strategy_vb.danger_y_base";
|
|
private static final String PREF_DISPLAYPORT_VB_DANGER_X_INCR = "gfx.displayport.strategy_vb.danger_x_incr";
|
|
private static final String PREF_DISPLAYPORT_VB_DANGER_Y_INCR = "gfx.displayport.strategy_vb.danger_y_incr";
|
|
private static final String PREF_DISPLAYPORT_PB_VELOCITY_THRESHOLD = "gfx.displayport.strategy_pb.threshold";
|
|
|
|
private static DisplayPortStrategy sStrategy = new VelocityBiasStrategy(null);
|
|
|
|
static DisplayPortMetrics calculate(ImmutableViewportMetrics metrics, PointF velocity) {
|
|
return sStrategy.calculate(metrics, (velocity == null ? ZERO_VELOCITY : velocity));
|
|
}
|
|
|
|
static boolean aboutToCheckerboard(ImmutableViewportMetrics metrics, PointF velocity, DisplayPortMetrics displayPort) {
|
|
if (displayPort == null) {
|
|
return true;
|
|
}
|
|
return sStrategy.aboutToCheckerboard(metrics, (velocity == null ? ZERO_VELOCITY : velocity), displayPort);
|
|
}
|
|
|
|
static boolean drawTimeUpdate(long millis, int pixels) {
|
|
return sStrategy.drawTimeUpdate(millis, pixels);
|
|
}
|
|
|
|
static void resetPageState() {
|
|
sStrategy.resetPageState();
|
|
}
|
|
|
|
static void addPrefNames(JSONArray prefs) {
|
|
prefs.put(PREF_DISPLAYPORT_STRATEGY);
|
|
prefs.put(PREF_DISPLAYPORT_FM_MULTIPLIER);
|
|
prefs.put(PREF_DISPLAYPORT_FM_DANGER_X);
|
|
prefs.put(PREF_DISPLAYPORT_FM_DANGER_Y);
|
|
prefs.put(PREF_DISPLAYPORT_VB_MULTIPLIER);
|
|
prefs.put(PREF_DISPLAYPORT_VB_VELOCITY_THRESHOLD);
|
|
prefs.put(PREF_DISPLAYPORT_VB_REVERSE_BUFFER);
|
|
prefs.put(PREF_DISPLAYPORT_VB_DANGER_X_BASE);
|
|
prefs.put(PREF_DISPLAYPORT_VB_DANGER_Y_BASE);
|
|
prefs.put(PREF_DISPLAYPORT_VB_DANGER_X_INCR);
|
|
prefs.put(PREF_DISPLAYPORT_VB_DANGER_Y_INCR);
|
|
prefs.put(PREF_DISPLAYPORT_PB_VELOCITY_THRESHOLD);
|
|
}
|
|
|
|
/**
|
|
* Set the active strategy to use.
|
|
* See the gfx.displayport.strategy pref in mobile/android/app/mobile.js to see the
|
|
* mapping between ints and strategies.
|
|
*/
|
|
static boolean setStrategy(Map<String, Integer> prefs) {
|
|
Integer strategy = prefs.get(PREF_DISPLAYPORT_STRATEGY);
|
|
if (strategy == null) {
|
|
return false;
|
|
}
|
|
|
|
switch (strategy) {
|
|
case 0:
|
|
sStrategy = new FixedMarginStrategy(prefs);
|
|
break;
|
|
case 1:
|
|
sStrategy = new VelocityBiasStrategy(prefs);
|
|
break;
|
|
case 2:
|
|
sStrategy = new DynamicResolutionStrategy(prefs);
|
|
break;
|
|
case 3:
|
|
sStrategy = new NoMarginStrategy(prefs);
|
|
break;
|
|
case 4:
|
|
sStrategy = new PredictionBiasStrategy(prefs);
|
|
break;
|
|
default:
|
|
Log.e(LOGTAG, "Invalid strategy index specified");
|
|
return false;
|
|
}
|
|
Log.i(LOGTAG, "Set strategy " + sStrategy.toString());
|
|
return true;
|
|
}
|
|
|
|
private static float getFloatPref(Map<String, Integer> prefs, String prefName, int defaultValue) {
|
|
Integer value = (prefs == null ? null : prefs.get(prefName));
|
|
return (float)(value == null || value < 0 ? defaultValue : value) / 1000f;
|
|
}
|
|
|
|
private static abstract class DisplayPortStrategy {
|
|
/** Calculates a displayport given a viewport and panning velocity. */
|
|
public abstract DisplayPortMetrics calculate(ImmutableViewportMetrics metrics, PointF velocity);
|
|
/** Returns true if a checkerboard is about to be visible and we should not throttle drawing. */
|
|
public abstract boolean aboutToCheckerboard(ImmutableViewportMetrics metrics, PointF velocity, DisplayPortMetrics displayPort);
|
|
/** Notify the strategy of a new recorded draw time. Return false to turn off draw time recording. */
|
|
public boolean drawTimeUpdate(long millis, int pixels) { return false; }
|
|
/** Reset any page-specific state stored, as the page being displayed has changed. */
|
|
public void resetPageState() {}
|
|
}
|
|
|
|
/**
|
|
* Return the dimensions for a rect that has area (width*height) that does not exceed the page size in the
|
|
* given metrics object. The area in the returned FloatSize may be less than width*height if the page is
|
|
* small, but it will never be larger than width*height.
|
|
* Note that this process may change the relative aspect ratio of the given dimensions.
|
|
*/
|
|
private static FloatSize reshapeForPage(float width, float height, ImmutableViewportMetrics metrics) {
|
|
// figure out how much of the desired buffer amount we can actually use on the horizontal axis
|
|
float usableWidth = Math.min(width, metrics.getPageWidth());
|
|
// if we reduced the buffer amount on the horizontal axis, we should take that saved memory and
|
|
// use it on the vertical axis
|
|
float extraUsableHeight = (float)Math.floor(((width - usableWidth) * height) / usableWidth);
|
|
float usableHeight = Math.min(height + extraUsableHeight, metrics.getPageHeight());
|
|
if (usableHeight < height && usableWidth == width) {
|
|
// and the reverse - if we shrunk the buffer on the vertical axis we can add it to the horizontal
|
|
float extraUsableWidth = (float)Math.floor(((height - usableHeight) * width) / usableHeight);
|
|
usableWidth = Math.min(width + extraUsableWidth, metrics.getPageWidth());
|
|
}
|
|
return new FloatSize(usableWidth, usableHeight);
|
|
}
|
|
|
|
/**
|
|
* Expand the given rect in all directions by a "danger zone". The size of the danger zone on an axis
|
|
* is the size of the view on that axis multiplied by the given multiplier. The expanded rect is then
|
|
* clamped to page bounds and returned.
|
|
*/
|
|
private static RectF expandByDangerZone(RectF rect, float dangerZoneXMultiplier, float dangerZoneYMultiplier, ImmutableViewportMetrics metrics) {
|
|
// calculate the danger zone amounts in pixels
|
|
float dangerZoneX = metrics.getWidth() * dangerZoneXMultiplier;
|
|
float dangerZoneY = metrics.getHeight() * dangerZoneYMultiplier;
|
|
rect = RectUtils.expand(rect, dangerZoneX, dangerZoneY);
|
|
// clamp to page bounds
|
|
return clampToPageBounds(rect, metrics);
|
|
}
|
|
|
|
/**
|
|
* Expand the given margins such that when they are applied on the viewport, the resulting rect
|
|
* does not have any partial tiles, except when it is clipped by the page bounds. This assumes
|
|
* the tiles are TILE_SIZE by TILE_SIZE and start at the origin, such that there will always be
|
|
* a tile at (0,0)-(TILE_SIZE,TILE_SIZE)).
|
|
*/
|
|
private static DisplayPortMetrics getTileAlignedDisplayPortMetrics(RectF margins, float zoom, ImmutableViewportMetrics metrics) {
|
|
float left = metrics.viewportRectLeft - margins.left;
|
|
float top = metrics.viewportRectTop - margins.top;
|
|
float right = metrics.viewportRectRight + margins.right;
|
|
float bottom = metrics.viewportRectBottom + margins.bottom;
|
|
left = Math.max(metrics.pageRectLeft, TILE_SIZE * FloatMath.floor(left / TILE_SIZE));
|
|
top = Math.max(metrics.pageRectTop, TILE_SIZE * FloatMath.floor(top / TILE_SIZE));
|
|
right = Math.min(metrics.pageRectRight, TILE_SIZE * FloatMath.ceil(right / TILE_SIZE));
|
|
bottom = Math.min(metrics.pageRectBottom, TILE_SIZE * FloatMath.ceil(bottom / TILE_SIZE));
|
|
return new DisplayPortMetrics(left, top, right, bottom, zoom);
|
|
}
|
|
|
|
/**
|
|
* Adjust the given margins so if they are applied on the viewport in the metrics, the resulting rect
|
|
* does not exceed the page bounds. This code will maintain the total margin amount for a given axis;
|
|
* it assumes that margins.left + metrics.getWidth() + margins.right is less than or equal to
|
|
* metrics.getPageWidth(); and the same for the y axis.
|
|
*/
|
|
private static RectF shiftMarginsForPageBounds(RectF margins, ImmutableViewportMetrics metrics) {
|
|
// check how much we're overflowing in each direction. note that at most one of leftOverflow
|
|
// and rightOverflow can be greater than zero, and at most one of topOverflow and bottomOverflow
|
|
// can be greater than zero, because of the assumption described in the method javadoc.
|
|
float leftOverflow = metrics.pageRectLeft - (metrics.viewportRectLeft - margins.left);
|
|
float rightOverflow = (metrics.viewportRectRight + margins.right) - metrics.pageRectRight;
|
|
float topOverflow = metrics.pageRectTop - (metrics.viewportRectTop - margins.top);
|
|
float bottomOverflow = (metrics.viewportRectBottom + margins.bottom) - metrics.pageRectBottom;
|
|
|
|
// if the margins overflow the page bounds, shift them to other side on the same axis
|
|
if (leftOverflow > 0) {
|
|
margins.left -= leftOverflow;
|
|
margins.right += leftOverflow;
|
|
} else if (rightOverflow > 0) {
|
|
margins.right -= rightOverflow;
|
|
margins.left += rightOverflow;
|
|
}
|
|
if (topOverflow > 0) {
|
|
margins.top -= topOverflow;
|
|
margins.bottom += topOverflow;
|
|
} else if (bottomOverflow > 0) {
|
|
margins.bottom -= bottomOverflow;
|
|
margins.top += bottomOverflow;
|
|
}
|
|
return margins;
|
|
}
|
|
|
|
/**
|
|
* Clamp the given rect to the page bounds and return it.
|
|
*/
|
|
private static RectF clampToPageBounds(RectF rect, ImmutableViewportMetrics metrics) {
|
|
if (rect.top < metrics.pageRectTop) rect.top = metrics.pageRectTop;
|
|
if (rect.left < metrics.pageRectLeft) rect.left = metrics.pageRectLeft;
|
|
if (rect.right > metrics.pageRectRight) rect.right = metrics.pageRectRight;
|
|
if (rect.bottom > metrics.pageRectBottom) rect.bottom = metrics.pageRectBottom;
|
|
return rect;
|
|
}
|
|
|
|
/**
|
|
* This class implements the variation where we basically don't bother with a a display port.
|
|
*/
|
|
private static class NoMarginStrategy extends DisplayPortStrategy {
|
|
NoMarginStrategy(Map<String, Integer> prefs) {
|
|
// no prefs in this strategy
|
|
}
|
|
|
|
public DisplayPortMetrics calculate(ImmutableViewportMetrics metrics, PointF velocity) {
|
|
return new DisplayPortMetrics(metrics.viewportRectLeft,
|
|
metrics.viewportRectTop,
|
|
metrics.viewportRectRight,
|
|
metrics.viewportRectBottom,
|
|
metrics.zoomFactor);
|
|
}
|
|
|
|
public boolean aboutToCheckerboard(ImmutableViewportMetrics metrics, PointF velocity, DisplayPortMetrics displayPort) {
|
|
return true;
|
|
}
|
|
|
|
@Override
|
|
public String toString() {
|
|
return "NoMarginStrategy";
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This class implements the variation where we use a fixed-size margin on the display port.
|
|
* The margin is always 300 pixels in all directions, except when we are (a) approaching a page
|
|
* boundary, and/or (b) if we are limited by the page size. In these cases we try to maintain
|
|
* the area of the display port by (a) shifting the buffer to the other side on the same axis,
|
|
* and/or (b) increasing the buffer on the other axis to compensate for the reduced buffer on
|
|
* one axis.
|
|
*/
|
|
private static class FixedMarginStrategy extends DisplayPortStrategy {
|
|
// The length of each axis of the display port will be the corresponding view length
|
|
// multiplied by this factor.
|
|
private final float SIZE_MULTIPLIER;
|
|
|
|
// If the visible rect is within the danger zone (measured as a fraction of the view size
|
|
// from the edge of the displayport) we start redrawing to minimize checkerboarding.
|
|
private final float DANGER_ZONE_X_MULTIPLIER;
|
|
private final float DANGER_ZONE_Y_MULTIPLIER;
|
|
|
|
FixedMarginStrategy(Map<String, Integer> prefs) {
|
|
SIZE_MULTIPLIER = getFloatPref(prefs, PREF_DISPLAYPORT_FM_MULTIPLIER, 2000);
|
|
DANGER_ZONE_X_MULTIPLIER = getFloatPref(prefs, PREF_DISPLAYPORT_FM_DANGER_X, 100);
|
|
DANGER_ZONE_Y_MULTIPLIER = getFloatPref(prefs, PREF_DISPLAYPORT_FM_DANGER_Y, 200);
|
|
}
|
|
|
|
public DisplayPortMetrics calculate(ImmutableViewportMetrics metrics, PointF velocity) {
|
|
float displayPortWidth = metrics.getWidth() * SIZE_MULTIPLIER;
|
|
float displayPortHeight = metrics.getHeight() * SIZE_MULTIPLIER;
|
|
|
|
// we need to avoid having a display port that is larger than the page, or we will end up
|
|
// painting things outside the page bounds (bug 729169). we simultaneously need to make
|
|
// the display port as large as possible so that we redraw less. reshape the display
|
|
// port dimensions to accomplish this.
|
|
FloatSize usableSize = reshapeForPage(displayPortWidth, displayPortHeight, metrics);
|
|
float horizontalBuffer = usableSize.width - metrics.getWidth();
|
|
float verticalBuffer = usableSize.height - metrics.getHeight();
|
|
|
|
// and now calculate the display port margins based on how much buffer we've decided to use and
|
|
// the page bounds, ensuring we use all of the available buffer amounts on one side or the other
|
|
// on any given axis. (i.e. if we're scrolled to the top of the page, the vertical buffer is
|
|
// entirely below the visible viewport, but if we're halfway down the page, the vertical buffer
|
|
// is split).
|
|
RectF margins = new RectF();
|
|
margins.left = horizontalBuffer / 2.0f;
|
|
margins.right = horizontalBuffer - margins.left;
|
|
margins.top = verticalBuffer / 2.0f;
|
|
margins.bottom = verticalBuffer - margins.top;
|
|
margins = shiftMarginsForPageBounds(margins, metrics);
|
|
|
|
return getTileAlignedDisplayPortMetrics(margins, metrics.zoomFactor, metrics);
|
|
}
|
|
|
|
public boolean aboutToCheckerboard(ImmutableViewportMetrics metrics, PointF velocity, DisplayPortMetrics displayPort) {
|
|
// Increase the size of the viewport based on the danger zone multiplier (and clamp to page
|
|
// boundaries), and intersect it with the current displayport to determine whether we're
|
|
// close to checkerboarding.
|
|
RectF adjustedViewport = expandByDangerZone(metrics.getViewport(), DANGER_ZONE_X_MULTIPLIER, DANGER_ZONE_Y_MULTIPLIER, metrics);
|
|
return !displayPort.contains(adjustedViewport);
|
|
}
|
|
|
|
@Override
|
|
public String toString() {
|
|
return "FixedMarginStrategy mult=" + SIZE_MULTIPLIER + ", dangerX=" + DANGER_ZONE_X_MULTIPLIER + ", dangerY=" + DANGER_ZONE_Y_MULTIPLIER;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This class implements the variation with a small fixed-size margin with velocity bias.
|
|
* In this variation, the default margins are pretty small relative to the view size, but
|
|
* they are affected by the panning velocity. Specifically, if we are panning on one axis,
|
|
* we remove the margins on the other axis because we are likely axis-locked. Also once
|
|
* we are panning in one direction above a certain threshold velocity, we shift the buffer
|
|
* so that it is almost entirely in the direction of the pan, with a little bit in the
|
|
* reverse direction.
|
|
*/
|
|
private static class VelocityBiasStrategy extends DisplayPortStrategy {
|
|
// The length of each axis of the display port will be the corresponding view length
|
|
// multiplied by this factor.
|
|
private final float SIZE_MULTIPLIER;
|
|
// The velocity above which we apply the velocity bias
|
|
private final float VELOCITY_THRESHOLD;
|
|
// How much of the buffer to keep in the reverse direction of the velocity
|
|
private final float REVERSE_BUFFER;
|
|
// If the visible rect is within the danger zone we start redrawing to minimize
|
|
// checkerboarding. the danger zone amount is a linear function of the form:
|
|
// viewportsize * (base + velocity * incr)
|
|
// where base and incr are configurable values.
|
|
private final float DANGER_ZONE_BASE_X_MULTIPLIER;
|
|
private final float DANGER_ZONE_BASE_Y_MULTIPLIER;
|
|
private final float DANGER_ZONE_INCR_X_MULTIPLIER;
|
|
private final float DANGER_ZONE_INCR_Y_MULTIPLIER;
|
|
|
|
VelocityBiasStrategy(Map<String, Integer> prefs) {
|
|
SIZE_MULTIPLIER = getFloatPref(prefs, PREF_DISPLAYPORT_VB_MULTIPLIER, 2000);
|
|
VELOCITY_THRESHOLD = GeckoAppShell.getDpi() * getFloatPref(prefs, PREF_DISPLAYPORT_VB_VELOCITY_THRESHOLD, 32);
|
|
REVERSE_BUFFER = getFloatPref(prefs, PREF_DISPLAYPORT_VB_REVERSE_BUFFER, 200);
|
|
DANGER_ZONE_BASE_X_MULTIPLIER = getFloatPref(prefs, PREF_DISPLAYPORT_VB_DANGER_X_BASE, 1000);
|
|
DANGER_ZONE_BASE_Y_MULTIPLIER = getFloatPref(prefs, PREF_DISPLAYPORT_VB_DANGER_Y_BASE, 1000);
|
|
DANGER_ZONE_INCR_X_MULTIPLIER = getFloatPref(prefs, PREF_DISPLAYPORT_VB_DANGER_X_INCR, 0);
|
|
DANGER_ZONE_INCR_Y_MULTIPLIER = getFloatPref(prefs, PREF_DISPLAYPORT_VB_DANGER_Y_INCR, 0);
|
|
}
|
|
|
|
/**
|
|
* Split the given amounts into margins based on the VELOCITY_THRESHOLD and REVERSE_BUFFER values.
|
|
* If the velocity is above the VELOCITY_THRESHOLD on an axis, split the amount into REVERSE_BUFFER
|
|
* and 1.0 - REVERSE_BUFFER fractions. The REVERSE_BUFFER fraction is set as the margin in the
|
|
* direction opposite to the velocity, and the remaining fraction is set as the margin in the direction
|
|
* of the velocity. If the velocity is lower than VELOCITY_THRESHOLD, split the amount evenly into the
|
|
* two margins on that axis.
|
|
*/
|
|
private RectF velocityBiasedMargins(float xAmount, float yAmount, PointF velocity) {
|
|
RectF margins = new RectF();
|
|
|
|
if (velocity.x > VELOCITY_THRESHOLD) {
|
|
margins.left = xAmount * REVERSE_BUFFER;
|
|
} else if (velocity.x < -VELOCITY_THRESHOLD) {
|
|
margins.left = xAmount * (1.0f - REVERSE_BUFFER);
|
|
} else {
|
|
margins.left = xAmount / 2.0f;
|
|
}
|
|
margins.right = xAmount - margins.left;
|
|
|
|
if (velocity.y > VELOCITY_THRESHOLD) {
|
|
margins.top = yAmount * REVERSE_BUFFER;
|
|
} else if (velocity.y < -VELOCITY_THRESHOLD) {
|
|
margins.top = yAmount * (1.0f - REVERSE_BUFFER);
|
|
} else {
|
|
margins.top = yAmount / 2.0f;
|
|
}
|
|
margins.bottom = yAmount - margins.top;
|
|
|
|
return margins;
|
|
}
|
|
|
|
public DisplayPortMetrics calculate(ImmutableViewportMetrics metrics, PointF velocity) {
|
|
float displayPortWidth = metrics.getWidth() * SIZE_MULTIPLIER;
|
|
float displayPortHeight = metrics.getHeight() * SIZE_MULTIPLIER;
|
|
|
|
// but if we're panning on one axis, set the margins for the other axis to zero since we are likely
|
|
// axis locked and won't be displaying that extra area.
|
|
if (Math.abs(velocity.x) > VELOCITY_THRESHOLD && FloatUtils.fuzzyEquals(velocity.y, 0)) {
|
|
displayPortHeight = metrics.getHeight();
|
|
} else if (Math.abs(velocity.y) > VELOCITY_THRESHOLD && FloatUtils.fuzzyEquals(velocity.x, 0)) {
|
|
displayPortWidth = metrics.getWidth();
|
|
}
|
|
|
|
// we need to avoid having a display port that is larger than the page, or we will end up
|
|
// painting things outside the page bounds (bug 729169).
|
|
displayPortWidth = Math.min(displayPortWidth, metrics.getPageWidth());
|
|
displayPortHeight = Math.min(displayPortHeight, metrics.getPageHeight());
|
|
float horizontalBuffer = displayPortWidth - metrics.getWidth();
|
|
float verticalBuffer = displayPortHeight - metrics.getHeight();
|
|
|
|
// split the buffer amounts into margins based on velocity, and shift it to
|
|
// take into account the page bounds
|
|
RectF margins = velocityBiasedMargins(horizontalBuffer, verticalBuffer, velocity);
|
|
margins = shiftMarginsForPageBounds(margins, metrics);
|
|
|
|
return getTileAlignedDisplayPortMetrics(margins, metrics.zoomFactor, metrics);
|
|
}
|
|
|
|
public boolean aboutToCheckerboard(ImmutableViewportMetrics metrics, PointF velocity, DisplayPortMetrics displayPort) {
|
|
// calculate the danger zone amounts based on the prefs
|
|
float dangerZoneX = metrics.getWidth() * (DANGER_ZONE_BASE_X_MULTIPLIER + (velocity.x * DANGER_ZONE_INCR_X_MULTIPLIER));
|
|
float dangerZoneY = metrics.getHeight() * (DANGER_ZONE_BASE_Y_MULTIPLIER + (velocity.y * DANGER_ZONE_INCR_Y_MULTIPLIER));
|
|
// clamp it such that when added to the viewport, they don't exceed page size.
|
|
// this is a prerequisite to calling shiftMarginsForPageBounds as we do below.
|
|
dangerZoneX = Math.min(dangerZoneX, metrics.getPageWidth() - metrics.getWidth());
|
|
dangerZoneY = Math.min(dangerZoneY, metrics.getPageHeight() - metrics.getHeight());
|
|
|
|
// split the danger zone into margins based on velocity, and ensure it doesn't exceed
|
|
// page bounds.
|
|
RectF dangerMargins = velocityBiasedMargins(dangerZoneX, dangerZoneY, velocity);
|
|
dangerMargins = shiftMarginsForPageBounds(dangerMargins, metrics);
|
|
|
|
// we're about to checkerboard if the current viewport area + the danger zone margins
|
|
// fall out of the current displayport anywhere.
|
|
RectF adjustedViewport = new RectF(
|
|
metrics.viewportRectLeft - dangerMargins.left,
|
|
metrics.viewportRectTop - dangerMargins.top,
|
|
metrics.viewportRectRight + dangerMargins.right,
|
|
metrics.viewportRectBottom + dangerMargins.bottom);
|
|
return !displayPort.contains(adjustedViewport);
|
|
}
|
|
|
|
@Override
|
|
public String toString() {
|
|
return "VelocityBiasStrategy mult=" + SIZE_MULTIPLIER + ", threshold=" + VELOCITY_THRESHOLD + ", reverse=" + REVERSE_BUFFER
|
|
+ ", dangerBaseX=" + DANGER_ZONE_BASE_X_MULTIPLIER + ", dangerBaseY=" + DANGER_ZONE_BASE_Y_MULTIPLIER
|
|
+ ", dangerIncrX=" + DANGER_ZONE_INCR_Y_MULTIPLIER + ", dangerIncrY=" + DANGER_ZONE_INCR_Y_MULTIPLIER;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This class implements the variation where we draw more of the page at low resolution while panning.
|
|
* In this variation, as we pan faster, we increase the page area we are drawing, but reduce the draw
|
|
* resolution to compensate. This results in the same device-pixel area drawn; the compositor then
|
|
* scales this up to the viewport zoom level. This results in a large area of the page drawn but it
|
|
* looks blurry. The assumption is that drawing extra that we never display is better than checkerboarding,
|
|
* where we draw less but never even show it on the screen.
|
|
*/
|
|
private static class DynamicResolutionStrategy extends DisplayPortStrategy {
|
|
// The length of each axis of the display port will be the corresponding view length
|
|
// multiplied by this factor.
|
|
private static final float SIZE_MULTIPLIER = 1.5f;
|
|
|
|
// The velocity above which we start zooming out the display port to keep up
|
|
// with the panning.
|
|
private static final float VELOCITY_EXPANSION_THRESHOLD = GeckoAppShell.getDpi() / 16f;
|
|
|
|
// How much we increase the display port based on velocity. Assuming no friction and
|
|
// splitting (see below), this should be be the number of frames (@60fps) between us
|
|
// calculating the display port and the draw of the *next* display port getting composited
|
|
// and displayed on the screen. This is because the timeline looks like this:
|
|
// Java: pan pan pan pan pan pan ! pan pan pan pan pan pan !
|
|
// Gecko: \-> draw -> composite / \-> draw -> composite /
|
|
// The display port calculated on the first "pan" gets composited to the screen at the
|
|
// first exclamation mark, and remains on the screen until the second exclamation mark.
|
|
// In order to avoid checkerboarding, that display port must be able to contain all of
|
|
// the panning until the second exclamation mark, which encompasses two entire draw/composite
|
|
// cycles.
|
|
// If we take into account friction, our velocity multiplier should be reduced as the
|
|
// amount of pan will decrease each time. If we take into account display port splitting,
|
|
// it should be increased as the splitting means some of the display port will be used to
|
|
// draw in the opposite direction of the velocity. For now I'm assuming these two cancel
|
|
// each other out.
|
|
private static final float VELOCITY_MULTIPLIER = 60.0f;
|
|
|
|
// The following constants adjust how biased the display port is in the direction of panning.
|
|
// When panning fast (above the FAST_THRESHOLD) we use the fast split factor to split the
|
|
// display port "buffer" area, otherwise we use the slow split factor. This is based on the
|
|
// assumption that if the user is panning fast, they are less likely to reverse directions
|
|
// and go backwards, so we should spend more of our display port buffer in the direction of
|
|
// panning.
|
|
private static final float VELOCITY_FAST_THRESHOLD = VELOCITY_EXPANSION_THRESHOLD * 2.0f;
|
|
private static final float FAST_SPLIT_FACTOR = 0.95f;
|
|
private static final float SLOW_SPLIT_FACTOR = 0.8f;
|
|
|
|
// The following constants are used for viewport prediction; we use them to estimate where
|
|
// the viewport will be soon and whether or not we should trigger a draw right now. "soon"
|
|
// in the previous sentence really refers to the amount of time it would take to draw and
|
|
// composite from the point at which we do the calculation, and that is not really a known
|
|
// quantity. The velocity multiplier is how much we multiply the velocity by; it has the
|
|
// same caveats as the VELOCITY_MULTIPLIER above except that it only needs to take into account
|
|
// one draw/composite cycle instead of two. The danger zone multiplier is a multiplier of the
|
|
// viewport size that we use as an extra "danger zone" around the viewport; if this danger
|
|
// zone falls outside the display port then we are approaching the point at which we will
|
|
// checkerboard, and hence should start drawing. Note that if DANGER_ZONE_MULTIPLIER is
|
|
// greater than (SIZE_MULTIPLIER - 1.0f), then at zero velocity we will always be in the
|
|
// danger zone, and thus will be constantly drawing.
|
|
private static final float PREDICTION_VELOCITY_MULTIPLIER = 30.0f;
|
|
private static final float DANGER_ZONE_MULTIPLIER = 0.20f; // must be less than (SIZE_MULTIPLIER - 1.0f)
|
|
|
|
DynamicResolutionStrategy(Map<String, Integer> prefs) {
|
|
// ignore prefs for now
|
|
}
|
|
|
|
public DisplayPortMetrics calculate(ImmutableViewportMetrics metrics, PointF velocity) {
|
|
float displayPortWidth = metrics.getWidth() * SIZE_MULTIPLIER;
|
|
float displayPortHeight = metrics.getHeight() * SIZE_MULTIPLIER;
|
|
|
|
// for resolution calculation purposes, we need to know what the adjusted display port dimensions
|
|
// would be if we had zero velocity, so calculate that here before we increase the display port
|
|
// based on velocity.
|
|
FloatSize reshapedSize = reshapeForPage(displayPortWidth, displayPortHeight, metrics);
|
|
|
|
// increase displayPortWidth and displayPortHeight based on the velocity, but maintaining their
|
|
// relative aspect ratio.
|
|
if (velocity.length() > VELOCITY_EXPANSION_THRESHOLD) {
|
|
float velocityFactor = Math.max(Math.abs(velocity.x) / displayPortWidth,
|
|
Math.abs(velocity.y) / displayPortHeight);
|
|
velocityFactor *= VELOCITY_MULTIPLIER;
|
|
|
|
displayPortWidth += (displayPortWidth * velocityFactor);
|
|
displayPortHeight += (displayPortHeight * velocityFactor);
|
|
}
|
|
|
|
// at this point, displayPortWidth and displayPortHeight are how much of the page (in device pixels)
|
|
// we want to be rendered by Gecko. Note here "device pixels" is equivalent to CSS pixels multiplied
|
|
// by metrics.zoomFactor
|
|
|
|
// we need to avoid having a display port that is larger than the page, or we will end up
|
|
// painting things outside the page bounds (bug 729169). we simultaneously need to make
|
|
// the display port as large as possible so that we redraw less. reshape the display
|
|
// port dimensions to accomplish this. this may change the aspect ratio of the display port,
|
|
// but we are assuming that this is desirable because the advantages from pre-drawing will
|
|
// outweigh the disadvantages from any buffer reallocations that might occur.
|
|
FloatSize usableSize = reshapeForPage(displayPortWidth, displayPortHeight, metrics);
|
|
float horizontalBuffer = usableSize.width - metrics.getWidth();
|
|
float verticalBuffer = usableSize.height - metrics.getHeight();
|
|
|
|
// at this point, horizontalBuffer and verticalBuffer are the dimensions of the buffer area we have.
|
|
// the buffer area is the off-screen area that is part of the display port and will be pre-drawn in case
|
|
// the user scrolls there. we now need to split the buffer area on each axis so that we know
|
|
// what the exact margins on each side will be. first we split the buffer amount based on the direction
|
|
// we're moving, so that we have a larger buffer in the direction of travel.
|
|
RectF margins = new RectF();
|
|
margins.left = splitBufferByVelocity(horizontalBuffer, velocity.x);
|
|
margins.right = horizontalBuffer - margins.left;
|
|
margins.top = splitBufferByVelocity(verticalBuffer, velocity.y);
|
|
margins.bottom = verticalBuffer - margins.top;
|
|
|
|
// then, we account for running into the page bounds - so that if we hit the top of the page, we need
|
|
// to drop the top margin and move that amount to the bottom margin.
|
|
margins = shiftMarginsForPageBounds(margins, metrics);
|
|
|
|
// finally, we calculate the resolution we want to render the display port area at. We do this
|
|
// so that as we expand the display port area (because of velocity), we reduce the resolution of
|
|
// the painted area so as to maintain the size of the buffer Gecko is painting into. we calculate
|
|
// the reduction in resolution by comparing the display port size with and without the velocity
|
|
// changes applied.
|
|
// this effectively means that as we pan faster and faster, the display port grows, but we paint
|
|
// at lower resolutions. this paints more area to reduce checkerboard at the cost of increasing
|
|
// compositor-scaling and blurriness. Once we stop panning, the blurriness must be entirely gone.
|
|
// Note that usable* could be less than base* if we are pinch-zoomed out into overscroll, so we
|
|
// clamp it to make sure this doesn't increase our display resolution past metrics.zoomFactor.
|
|
float scaleFactor = Math.min(reshapedSize.width / usableSize.width, reshapedSize.height / usableSize.height);
|
|
float displayResolution = metrics.zoomFactor * Math.min(1.0f, scaleFactor);
|
|
|
|
DisplayPortMetrics dpMetrics = new DisplayPortMetrics(
|
|
metrics.viewportRectLeft - margins.left,
|
|
metrics.viewportRectTop - margins.top,
|
|
metrics.viewportRectRight + margins.right,
|
|
metrics.viewportRectBottom + margins.bottom,
|
|
displayResolution);
|
|
return dpMetrics;
|
|
}
|
|
|
|
/**
|
|
* Split the given buffer amount into two based on the velocity.
|
|
* Given an amount of total usable buffer on an axis, this will
|
|
* return the amount that should be used on the left/top side of
|
|
* the axis (the side which a negative velocity vector corresponds
|
|
* to).
|
|
*/
|
|
private float splitBufferByVelocity(float amount, float velocity) {
|
|
// if no velocity, so split evenly
|
|
if (FloatUtils.fuzzyEquals(velocity, 0)) {
|
|
return amount / 2.0f;
|
|
}
|
|
// if we're moving quickly, assign more of the amount in that direction
|
|
// since is is less likely that we will reverse direction immediately
|
|
if (velocity < -VELOCITY_FAST_THRESHOLD) {
|
|
return amount * FAST_SPLIT_FACTOR;
|
|
}
|
|
if (velocity > VELOCITY_FAST_THRESHOLD) {
|
|
return amount * (1.0f - FAST_SPLIT_FACTOR);
|
|
}
|
|
// if we're moving slowly, then assign less of the amount in that direction
|
|
if (velocity < 0) {
|
|
return amount * SLOW_SPLIT_FACTOR;
|
|
} else {
|
|
return amount * (1.0f - SLOW_SPLIT_FACTOR);
|
|
}
|
|
}
|
|
|
|
public boolean aboutToCheckerboard(ImmutableViewportMetrics metrics, PointF velocity, DisplayPortMetrics displayPort) {
|
|
// Expand the viewport based on our velocity (and clamp it to page boundaries).
|
|
// Then intersect it with the last-requested displayport to determine whether we're
|
|
// close to checkerboarding.
|
|
|
|
RectF predictedViewport = metrics.getViewport();
|
|
|
|
// first we expand the viewport in the direction we're moving based on some
|
|
// multiple of the current velocity.
|
|
if (velocity.length() > 0) {
|
|
if (velocity.x < 0) {
|
|
predictedViewport.left += velocity.x * PREDICTION_VELOCITY_MULTIPLIER;
|
|
} else if (velocity.x > 0) {
|
|
predictedViewport.right += velocity.x * PREDICTION_VELOCITY_MULTIPLIER;
|
|
}
|
|
|
|
if (velocity.y < 0) {
|
|
predictedViewport.top += velocity.y * PREDICTION_VELOCITY_MULTIPLIER;
|
|
} else if (velocity.y > 0) {
|
|
predictedViewport.bottom += velocity.y * PREDICTION_VELOCITY_MULTIPLIER;
|
|
}
|
|
}
|
|
|
|
// then we expand the viewport evenly in all directions just to have an extra
|
|
// safety zone. this also clamps it to page bounds.
|
|
predictedViewport = expandByDangerZone(predictedViewport, DANGER_ZONE_MULTIPLIER, DANGER_ZONE_MULTIPLIER, metrics);
|
|
return !displayPort.contains(predictedViewport);
|
|
}
|
|
|
|
@Override
|
|
public String toString() {
|
|
return "DynamicResolutionStrategy";
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This class implements the variation where we use the draw time to predict where we will be when
|
|
* a draw completes, and draw that instead of where we are now. In this variation, when our panning
|
|
* speed drops below a certain threshold, we draw 9 viewports' worth of content so that the user can
|
|
* pan in any direction without encountering checkerboarding.
|
|
* Once the user is panning, we modify the displayport to encompass an area range of where we think
|
|
* the user will be when the draw completes. This heuristic relies on both the estimated draw time
|
|
* the panning velocity; unexpected changes in either of these values will cause the heuristic to
|
|
* fail and show checkerboard.
|
|
*/
|
|
private static class PredictionBiasStrategy extends DisplayPortStrategy {
|
|
private static float VELOCITY_THRESHOLD;
|
|
|
|
private int mPixelArea; // area of the viewport, used in draw time calculations
|
|
private int mMinFramesToDraw; // minimum number of frames we take to draw
|
|
private int mMaxFramesToDraw; // maximum number of frames we take to draw
|
|
|
|
PredictionBiasStrategy(Map<String, Integer> prefs) {
|
|
VELOCITY_THRESHOLD = GeckoAppShell.getDpi() * getFloatPref(prefs, PREF_DISPLAYPORT_PB_VELOCITY_THRESHOLD, 16);
|
|
resetPageState();
|
|
}
|
|
|
|
public DisplayPortMetrics calculate(ImmutableViewportMetrics metrics, PointF velocity) {
|
|
float width = metrics.getWidth();
|
|
float height = metrics.getHeight();
|
|
mPixelArea = (int)(width * height);
|
|
|
|
if (velocity.length() < VELOCITY_THRESHOLD) {
|
|
// if we're going slow, expand the displayport to 9x viewport size
|
|
RectF margins = new RectF(width, height, width, height);
|
|
return getTileAlignedDisplayPortMetrics(margins, metrics.zoomFactor, metrics);
|
|
}
|
|
|
|
// figure out how far we expect to be
|
|
float minDx = velocity.x * mMinFramesToDraw;
|
|
float minDy = velocity.y * mMinFramesToDraw;
|
|
float maxDx = velocity.x * mMaxFramesToDraw;
|
|
float maxDy = velocity.y * mMaxFramesToDraw;
|
|
|
|
// figure out how many pixels we will be drawing when we draw the above-calculated range.
|
|
// this will be larger than the viewport area.
|
|
float pixelsToDraw = (width + Math.abs(maxDx - minDx)) * (height + Math.abs(maxDy - minDy));
|
|
// adjust how far we will get because of the time spent drawing all these extra pixels. this
|
|
// will again increase the number of pixels drawn so really we could keep iterating this over
|
|
// and over, but once seems enough for now.
|
|
maxDx = maxDx * pixelsToDraw / mPixelArea;
|
|
maxDy = maxDy * pixelsToDraw / mPixelArea;
|
|
|
|
// and finally generate the displayport. the min/max stuff takes care of
|
|
// negative velocities as well as positive.
|
|
RectF margins = new RectF(
|
|
-Math.min(minDx, maxDx),
|
|
-Math.min(minDy, maxDy),
|
|
Math.max(minDx, maxDx),
|
|
Math.max(minDy, maxDy));
|
|
return getTileAlignedDisplayPortMetrics(margins, metrics.zoomFactor, metrics);
|
|
}
|
|
|
|
public boolean aboutToCheckerboard(ImmutableViewportMetrics metrics, PointF velocity, DisplayPortMetrics displayPort) {
|
|
// the code below is the same as in calculate() but is awkward to refactor since it has multiple outputs.
|
|
// refer to the comments in calculate() to understand what this is doing.
|
|
float minDx = velocity.x * mMinFramesToDraw;
|
|
float minDy = velocity.y * mMinFramesToDraw;
|
|
float maxDx = velocity.x * mMaxFramesToDraw;
|
|
float maxDy = velocity.y * mMaxFramesToDraw;
|
|
float pixelsToDraw = (metrics.getWidth() + Math.abs(maxDx - minDx)) * (metrics.getHeight() + Math.abs(maxDy - minDy));
|
|
maxDx = maxDx * pixelsToDraw / mPixelArea;
|
|
maxDy = maxDy * pixelsToDraw / mPixelArea;
|
|
|
|
// now that we have an idea of how far we will be when the draw completes, take the farthest
|
|
// end of that range and see if it falls outside the displayport bounds. if it does, allow
|
|
// the draw to go through
|
|
RectF predictedViewport = metrics.getViewport();
|
|
predictedViewport.left += maxDx;
|
|
predictedViewport.top += maxDy;
|
|
predictedViewport.right += maxDx;
|
|
predictedViewport.bottom += maxDy;
|
|
|
|
predictedViewport = clampToPageBounds(predictedViewport, metrics);
|
|
return !displayPort.contains(predictedViewport);
|
|
}
|
|
|
|
@Override
|
|
public boolean drawTimeUpdate(long millis, int pixels) {
|
|
// calculate the number of frames it took to draw a viewport-sized area
|
|
float normalizedTime = (float)mPixelArea * (float)millis / (float)pixels;
|
|
int normalizedFrames = (int)FloatMath.ceil(normalizedTime * 60f / 1000f);
|
|
// broaden our range on how long it takes to draw if the draw falls outside
|
|
// the range. this allows it to grow gradually. this heuristic may need to
|
|
// be tweaked into more of a floating window average or something.
|
|
if (normalizedFrames <= mMinFramesToDraw) {
|
|
mMinFramesToDraw--;
|
|
} else if (normalizedFrames > mMaxFramesToDraw) {
|
|
mMaxFramesToDraw++;
|
|
} else {
|
|
return true;
|
|
}
|
|
Log.d(LOGTAG, "Widened draw range to [" + mMinFramesToDraw + ", " + mMaxFramesToDraw + "]");
|
|
return true;
|
|
}
|
|
|
|
@Override
|
|
public void resetPageState() {
|
|
mMinFramesToDraw = 0;
|
|
mMaxFramesToDraw = 2;
|
|
}
|
|
|
|
@Override
|
|
public String toString() {
|
|
return "PredictionBiasStrategy threshold=" + VELOCITY_THRESHOLD;
|
|
}
|
|
}
|
|
}
|