1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/src/nsRenderingContext.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,581 @@
1.4 +/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#include "nsRenderingContext.h"
1.10 +#include <string.h> // for strlen
1.11 +#include <algorithm> // for min
1.12 +#include "gfxColor.h" // for gfxRGBA
1.13 +#include "gfxMatrix.h" // for gfxMatrix
1.14 +#include "gfxPoint.h" // for gfxPoint, gfxSize
1.15 +#include "gfxRect.h" // for gfxRect
1.16 +#include "gfxTypes.h" // for gfxFloat
1.17 +#include "mozilla/gfx/BasePoint.h" // for BasePoint
1.18 +#include "mozilla/mozalloc.h" // for operator delete[], etc
1.19 +#include "nsBoundingMetrics.h" // for nsBoundingMetrics
1.20 +#include "nsCharTraits.h" // for NS_IS_LOW_SURROGATE
1.21 +#include "nsDebug.h" // for NS_ERROR
1.22 +#include "nsPoint.h" // for nsPoint
1.23 +#include "nsRect.h" // for nsRect, nsIntRect
1.24 +#include "nsRegion.h" // for nsIntRegionRectIterator, etc
1.25 +
1.26 +class gfxASurface;
1.27 +
1.28 +// XXXTodo: rename FORM_TWIPS to FROM_APPUNITS
1.29 +#define FROM_TWIPS(_x) ((gfxFloat)((_x)/(mP2A)))
1.30 +#define FROM_TWIPS_INT(_x) (NSToIntRound((gfxFloat)((_x)/(mP2A))))
1.31 +#define TO_TWIPS(_x) ((nscoord)((_x)*(mP2A)))
1.32 +#define GFX_RECT_FROM_TWIPS_RECT(_r) (gfxRect(FROM_TWIPS((_r).x), FROM_TWIPS((_r).y), FROM_TWIPS((_r).width), FROM_TWIPS((_r).height)))
1.33 +
1.34 +// Hard limit substring lengths to 8000 characters ... this lets us statically
1.35 +// size the cluster buffer array in FindSafeLength
1.36 +#define MAX_GFX_TEXT_BUF_SIZE 8000
1.37 +
1.38 +static int32_t FindSafeLength(const char16_t *aString, uint32_t aLength,
1.39 + uint32_t aMaxChunkLength)
1.40 +{
1.41 + if (aLength <= aMaxChunkLength)
1.42 + return aLength;
1.43 +
1.44 + int32_t len = aMaxChunkLength;
1.45 +
1.46 + // Ensure that we don't break inside a surrogate pair
1.47 + while (len > 0 && NS_IS_LOW_SURROGATE(aString[len])) {
1.48 + len--;
1.49 + }
1.50 + if (len == 0) {
1.51 + // We don't want our caller to go into an infinite loop, so don't
1.52 + // return zero. It's hard to imagine how we could actually get here
1.53 + // unless there are languages that allow clusters of arbitrary size.
1.54 + // If there are and someone feeds us a 500+ character cluster, too
1.55 + // bad.
1.56 + return aMaxChunkLength;
1.57 + }
1.58 + return len;
1.59 +}
1.60 +
1.61 +static int32_t FindSafeLength(const char *aString, uint32_t aLength,
1.62 + uint32_t aMaxChunkLength)
1.63 +{
1.64 + // Since it's ASCII, we don't need to worry about clusters or RTL
1.65 + return std::min(aLength, aMaxChunkLength);
1.66 +}
1.67 +
1.68 +//////////////////////////////////////////////////////////////////////
1.69 +//// nsRenderingContext
1.70 +
1.71 +void
1.72 +nsRenderingContext::Init(nsDeviceContext* aContext,
1.73 + gfxASurface *aThebesSurface)
1.74 +{
1.75 + Init(aContext, new gfxContext(aThebesSurface));
1.76 +}
1.77 +
1.78 +void
1.79 +nsRenderingContext::Init(nsDeviceContext* aContext,
1.80 + gfxContext *aThebesContext)
1.81 +{
1.82 + mDeviceContext = aContext;
1.83 + mThebes = aThebesContext;
1.84 +
1.85 + mThebes->SetLineWidth(1.0);
1.86 + mP2A = mDeviceContext->AppUnitsPerDevPixel();
1.87 +}
1.88 +
1.89 +void
1.90 +nsRenderingContext::Init(nsDeviceContext* aContext,
1.91 + DrawTarget *aDrawTarget)
1.92 +{
1.93 + Init(aContext, new gfxContext(aDrawTarget));
1.94 +}
1.95 +
1.96 +//
1.97 +// graphics state
1.98 +//
1.99 +
1.100 +void
1.101 +nsRenderingContext::PushState()
1.102 +{
1.103 + mThebes->Save();
1.104 +}
1.105 +
1.106 +void
1.107 +nsRenderingContext::PopState()
1.108 +{
1.109 + mThebes->Restore();
1.110 +}
1.111 +
1.112 +void
1.113 +nsRenderingContext::IntersectClip(const nsRect& aRect)
1.114 +{
1.115 + mThebes->NewPath();
1.116 + gfxRect clipRect(GFX_RECT_FROM_TWIPS_RECT(aRect));
1.117 + if (mThebes->UserToDevicePixelSnapped(clipRect, true)) {
1.118 + gfxMatrix mat(mThebes->CurrentMatrix());
1.119 + mat.Invert();
1.120 + clipRect = mat.Transform(clipRect);
1.121 + mThebes->Rectangle(clipRect);
1.122 + } else {
1.123 + mThebes->Rectangle(clipRect);
1.124 + }
1.125 +
1.126 + mThebes->Clip();
1.127 +}
1.128 +
1.129 +void
1.130 +nsRenderingContext::SetClip(const nsIntRegion& aRegion)
1.131 +{
1.132 + // Region is in device coords, no transformation. This should
1.133 + // only be called when there is no transform in place, when we we
1.134 + // just start painting a widget. The region is set by the platform
1.135 + // paint routine. Therefore, there is no option to intersect with
1.136 + // an existing clip.
1.137 +
1.138 + gfxMatrix mat = mThebes->CurrentMatrix();
1.139 + mThebes->IdentityMatrix();
1.140 +
1.141 + mThebes->ResetClip();
1.142 +
1.143 + mThebes->NewPath();
1.144 + nsIntRegionRectIterator iter(aRegion);
1.145 + const nsIntRect* rect;
1.146 + while ((rect = iter.Next())) {
1.147 + mThebes->Rectangle(gfxRect(rect->x, rect->y, rect->width, rect->height),
1.148 + true);
1.149 + }
1.150 + mThebes->Clip();
1.151 + mThebes->SetMatrix(mat);
1.152 +}
1.153 +
1.154 +void
1.155 +nsRenderingContext::SetLineStyle(nsLineStyle aLineStyle)
1.156 +{
1.157 + switch (aLineStyle) {
1.158 + case nsLineStyle_kSolid:
1.159 + mThebes->SetDash(gfxContext::gfxLineSolid);
1.160 + break;
1.161 + case nsLineStyle_kDashed:
1.162 + mThebes->SetDash(gfxContext::gfxLineDashed);
1.163 + break;
1.164 + case nsLineStyle_kDotted:
1.165 + mThebes->SetDash(gfxContext::gfxLineDotted);
1.166 + break;
1.167 + case nsLineStyle_kNone:
1.168 + default:
1.169 + // nothing uses kNone
1.170 + NS_ERROR("SetLineStyle: Invalid line style");
1.171 + break;
1.172 + }
1.173 +}
1.174 +
1.175 +
1.176 +void
1.177 +nsRenderingContext::SetColor(nscolor aColor)
1.178 +{
1.179 + /* This sets the color assuming the sRGB color space, since that's
1.180 + * what all CSS colors are defined to be in by the spec.
1.181 + */
1.182 + mThebes->SetColor(gfxRGBA(aColor));
1.183 +}
1.184 +
1.185 +void
1.186 +nsRenderingContext::Translate(const nsPoint& aPt)
1.187 +{
1.188 + mThebes->Translate(gfxPoint(FROM_TWIPS(aPt.x), FROM_TWIPS(aPt.y)));
1.189 +}
1.190 +
1.191 +void
1.192 +nsRenderingContext::Scale(float aSx, float aSy)
1.193 +{
1.194 + mThebes->Scale(aSx, aSy);
1.195 +}
1.196 +
1.197 +//
1.198 +// shapes
1.199 +//
1.200 +
1.201 +void
1.202 +nsRenderingContext::DrawLine(const nsPoint& aStartPt, const nsPoint& aEndPt)
1.203 +{
1.204 + DrawLine(aStartPt.x, aStartPt.y, aEndPt.x, aEndPt.y);
1.205 +}
1.206 +
1.207 +void
1.208 +nsRenderingContext::DrawLine(nscoord aX0, nscoord aY0,
1.209 + nscoord aX1, nscoord aY1)
1.210 +{
1.211 + gfxPoint p0 = gfxPoint(FROM_TWIPS(aX0), FROM_TWIPS(aY0));
1.212 + gfxPoint p1 = gfxPoint(FROM_TWIPS(aX1), FROM_TWIPS(aY1));
1.213 +
1.214 + // we can't draw thick lines with gfx, so we always assume we want
1.215 + // pixel-aligned lines if the rendering context is at 1.0 scale
1.216 + gfxMatrix savedMatrix = mThebes->CurrentMatrix();
1.217 + if (!savedMatrix.HasNonTranslation()) {
1.218 + p0 = mThebes->UserToDevice(p0);
1.219 + p1 = mThebes->UserToDevice(p1);
1.220 +
1.221 + p0.Round();
1.222 + p1.Round();
1.223 +
1.224 + mThebes->IdentityMatrix();
1.225 +
1.226 + mThebes->NewPath();
1.227 +
1.228 + // snap straight lines
1.229 + if (p0.x == p1.x) {
1.230 + mThebes->Line(p0 + gfxPoint(0.5, 0),
1.231 + p1 + gfxPoint(0.5, 0));
1.232 + } else if (p0.y == p1.y) {
1.233 + mThebes->Line(p0 + gfxPoint(0, 0.5),
1.234 + p1 + gfxPoint(0, 0.5));
1.235 + } else {
1.236 + mThebes->Line(p0, p1);
1.237 + }
1.238 +
1.239 + mThebes->Stroke();
1.240 +
1.241 + mThebes->SetMatrix(savedMatrix);
1.242 + } else {
1.243 + mThebes->NewPath();
1.244 + mThebes->Line(p0, p1);
1.245 + mThebes->Stroke();
1.246 + }
1.247 +}
1.248 +
1.249 +void
1.250 +nsRenderingContext::DrawRect(const nsRect& aRect)
1.251 +{
1.252 + mThebes->NewPath();
1.253 + mThebes->Rectangle(GFX_RECT_FROM_TWIPS_RECT(aRect), true);
1.254 + mThebes->Stroke();
1.255 +}
1.256 +
1.257 +void
1.258 +nsRenderingContext::DrawRect(nscoord aX, nscoord aY,
1.259 + nscoord aWidth, nscoord aHeight)
1.260 +{
1.261 + DrawRect(nsRect(aX, aY, aWidth, aHeight));
1.262 +}
1.263 +
1.264 +
1.265 +/* Clamp r to (0,0) (2^23,2^23)
1.266 + * these are to be device coordinates.
1.267 + *
1.268 + * Returns false if the rectangle is completely out of bounds,
1.269 + * true otherwise.
1.270 + *
1.271 + * This function assumes that it will be called with a rectangle being
1.272 + * drawn into a surface with an identity transformation matrix; that
1.273 + * is, anything above or to the left of (0,0) will be offscreen.
1.274 + *
1.275 + * First it checks if the rectangle is entirely beyond
1.276 + * CAIRO_COORD_MAX; if so, it can't ever appear on the screen --
1.277 + * false is returned.
1.278 + *
1.279 + * Then it shifts any rectangles with x/y < 0 so that x and y are = 0,
1.280 + * and adjusts the width and height appropriately. For example, a
1.281 + * rectangle from (0,-5) with dimensions (5,10) will become a
1.282 + * rectangle from (0,0) with dimensions (5,5).
1.283 + *
1.284 + * If after negative x/y adjustment to 0, either the width or height
1.285 + * is negative, then the rectangle is completely offscreen, and
1.286 + * nothing is drawn -- false is returned.
1.287 + *
1.288 + * Finally, if x+width or y+height are greater than CAIRO_COORD_MAX,
1.289 + * the width and height are clamped such x+width or y+height are equal
1.290 + * to CAIRO_COORD_MAX, and true is returned.
1.291 + */
1.292 +#define CAIRO_COORD_MAX (double(0x7fffff))
1.293 +
1.294 +static bool
1.295 +ConditionRect(gfxRect& r) {
1.296 + // if either x or y is way out of bounds;
1.297 + // note that we don't handle negative w/h here
1.298 + if (r.X() > CAIRO_COORD_MAX || r.Y() > CAIRO_COORD_MAX)
1.299 + return false;
1.300 +
1.301 + if (r.X() < 0.0) {
1.302 + r.width += r.X();
1.303 + if (r.width < 0.0)
1.304 + return false;
1.305 + r.x = 0.0;
1.306 + }
1.307 +
1.308 + if (r.XMost() > CAIRO_COORD_MAX) {
1.309 + r.width = CAIRO_COORD_MAX - r.X();
1.310 + }
1.311 +
1.312 + if (r.Y() < 0.0) {
1.313 + r.height += r.Y();
1.314 + if (r.Height() < 0.0)
1.315 + return false;
1.316 +
1.317 + r.y = 0.0;
1.318 + }
1.319 +
1.320 + if (r.YMost() > CAIRO_COORD_MAX) {
1.321 + r.height = CAIRO_COORD_MAX - r.Y();
1.322 + }
1.323 + return true;
1.324 +}
1.325 +
1.326 +void
1.327 +nsRenderingContext::FillRect(const nsRect& aRect)
1.328 +{
1.329 + gfxRect r(GFX_RECT_FROM_TWIPS_RECT(aRect));
1.330 +
1.331 + /* Clamp coordinates to work around a design bug in cairo */
1.332 + nscoord bigval = (nscoord)(CAIRO_COORD_MAX*mP2A);
1.333 + if (aRect.width > bigval ||
1.334 + aRect.height > bigval ||
1.335 + aRect.x < -bigval ||
1.336 + aRect.x > bigval ||
1.337 + aRect.y < -bigval ||
1.338 + aRect.y > bigval)
1.339 + {
1.340 + gfxMatrix mat = mThebes->CurrentMatrix();
1.341 +
1.342 + r = mat.Transform(r);
1.343 +
1.344 + if (!ConditionRect(r))
1.345 + return;
1.346 +
1.347 + mThebes->IdentityMatrix();
1.348 + mThebes->NewPath();
1.349 +
1.350 + mThebes->Rectangle(r, true);
1.351 + mThebes->Fill();
1.352 + mThebes->SetMatrix(mat);
1.353 + }
1.354 +
1.355 + mThebes->NewPath();
1.356 + mThebes->Rectangle(r, true);
1.357 + mThebes->Fill();
1.358 +}
1.359 +
1.360 +void
1.361 +nsRenderingContext::FillRect(nscoord aX, nscoord aY,
1.362 + nscoord aWidth, nscoord aHeight)
1.363 +{
1.364 + FillRect(nsRect(aX, aY, aWidth, aHeight));
1.365 +}
1.366 +
1.367 +void
1.368 +nsRenderingContext::InvertRect(const nsRect& aRect)
1.369 +{
1.370 + gfxContext::GraphicsOperator lastOp = mThebes->CurrentOperator();
1.371 +
1.372 + mThebes->SetOperator(gfxContext::OPERATOR_XOR);
1.373 + FillRect(aRect);
1.374 + mThebes->SetOperator(lastOp);
1.375 +}
1.376 +
1.377 +void
1.378 +nsRenderingContext::DrawEllipse(nscoord aX, nscoord aY,
1.379 + nscoord aWidth, nscoord aHeight)
1.380 +{
1.381 + mThebes->NewPath();
1.382 + mThebes->Ellipse(gfxPoint(FROM_TWIPS(aX) + FROM_TWIPS(aWidth)/2.0,
1.383 + FROM_TWIPS(aY) + FROM_TWIPS(aHeight)/2.0),
1.384 + gfxSize(FROM_TWIPS(aWidth),
1.385 + FROM_TWIPS(aHeight)));
1.386 + mThebes->Stroke();
1.387 +}
1.388 +
1.389 +void
1.390 +nsRenderingContext::FillEllipse(const nsRect& aRect)
1.391 +{
1.392 + FillEllipse(aRect.x, aRect.y, aRect.width, aRect.height);
1.393 +}
1.394 +
1.395 +void
1.396 +nsRenderingContext::FillEllipse(nscoord aX, nscoord aY,
1.397 + nscoord aWidth, nscoord aHeight)
1.398 +{
1.399 + mThebes->NewPath();
1.400 + mThebes->Ellipse(gfxPoint(FROM_TWIPS(aX) + FROM_TWIPS(aWidth)/2.0,
1.401 + FROM_TWIPS(aY) + FROM_TWIPS(aHeight)/2.0),
1.402 + gfxSize(FROM_TWIPS(aWidth),
1.403 + FROM_TWIPS(aHeight)));
1.404 + mThebes->Fill();
1.405 +}
1.406 +
1.407 +void
1.408 +nsRenderingContext::FillPolygon(const nsPoint twPoints[], int32_t aNumPoints)
1.409 +{
1.410 + if (aNumPoints == 0)
1.411 + return;
1.412 +
1.413 + nsAutoArrayPtr<gfxPoint> pxPoints(new gfxPoint[aNumPoints]);
1.414 +
1.415 + for (int i = 0; i < aNumPoints; i++) {
1.416 + pxPoints[i].x = FROM_TWIPS(twPoints[i].x);
1.417 + pxPoints[i].y = FROM_TWIPS(twPoints[i].y);
1.418 + }
1.419 +
1.420 + mThebes->NewPath();
1.421 + mThebes->Polygon(pxPoints, aNumPoints);
1.422 + mThebes->Fill();
1.423 +}
1.424 +
1.425 +//
1.426 +// text
1.427 +//
1.428 +
1.429 +void
1.430 +nsRenderingContext::SetTextRunRTL(bool aIsRTL)
1.431 +{
1.432 + mFontMetrics->SetTextRunRTL(aIsRTL);
1.433 +}
1.434 +
1.435 +void
1.436 +nsRenderingContext::SetFont(nsFontMetrics *aFontMetrics)
1.437 +{
1.438 + mFontMetrics = aFontMetrics;
1.439 +}
1.440 +
1.441 +int32_t
1.442 +nsRenderingContext::GetMaxChunkLength()
1.443 +{
1.444 + if (!mFontMetrics)
1.445 + return 1;
1.446 + return std::min(mFontMetrics->GetMaxStringLength(), MAX_GFX_TEXT_BUF_SIZE);
1.447 +}
1.448 +
1.449 +nscoord
1.450 +nsRenderingContext::GetWidth(char aC)
1.451 +{
1.452 + if (aC == ' ' && mFontMetrics) {
1.453 + return mFontMetrics->SpaceWidth();
1.454 + }
1.455 +
1.456 + return GetWidth(&aC, 1);
1.457 +}
1.458 +
1.459 +nscoord
1.460 +nsRenderingContext::GetWidth(char16_t aC)
1.461 +{
1.462 + return GetWidth(&aC, 1);
1.463 +}
1.464 +
1.465 +nscoord
1.466 +nsRenderingContext::GetWidth(const nsString& aString)
1.467 +{
1.468 + return GetWidth(aString.get(), aString.Length());
1.469 +}
1.470 +
1.471 +nscoord
1.472 +nsRenderingContext::GetWidth(const char* aString)
1.473 +{
1.474 + return GetWidth(aString, strlen(aString));
1.475 +}
1.476 +
1.477 +nscoord
1.478 +nsRenderingContext::GetWidth(const char* aString, uint32_t aLength)
1.479 +{
1.480 + uint32_t maxChunkLength = GetMaxChunkLength();
1.481 + nscoord width = 0;
1.482 + while (aLength > 0) {
1.483 + int32_t len = FindSafeLength(aString, aLength, maxChunkLength);
1.484 + width += mFontMetrics->GetWidth(aString, len, this);
1.485 + aLength -= len;
1.486 + aString += len;
1.487 + }
1.488 + return width;
1.489 +}
1.490 +
1.491 +nscoord
1.492 +nsRenderingContext::GetWidth(const char16_t *aString, uint32_t aLength)
1.493 +{
1.494 + uint32_t maxChunkLength = GetMaxChunkLength();
1.495 + nscoord width = 0;
1.496 + while (aLength > 0) {
1.497 + int32_t len = FindSafeLength(aString, aLength, maxChunkLength);
1.498 + width += mFontMetrics->GetWidth(aString, len, this);
1.499 + aLength -= len;
1.500 + aString += len;
1.501 + }
1.502 + return width;
1.503 +}
1.504 +
1.505 +nsBoundingMetrics
1.506 +nsRenderingContext::GetBoundingMetrics(const char16_t* aString,
1.507 + uint32_t aLength)
1.508 +{
1.509 + uint32_t maxChunkLength = GetMaxChunkLength();
1.510 + int32_t len = FindSafeLength(aString, aLength, maxChunkLength);
1.511 + // Assign directly in the first iteration. This ensures that
1.512 + // negative ascent/descent can be returned and the left bearing
1.513 + // is properly initialized.
1.514 + nsBoundingMetrics totalMetrics
1.515 + = mFontMetrics->GetBoundingMetrics(aString, len, this);
1.516 + aLength -= len;
1.517 + aString += len;
1.518 +
1.519 + while (aLength > 0) {
1.520 + len = FindSafeLength(aString, aLength, maxChunkLength);
1.521 + nsBoundingMetrics metrics
1.522 + = mFontMetrics->GetBoundingMetrics(aString, len, this);
1.523 + totalMetrics += metrics;
1.524 + aLength -= len;
1.525 + aString += len;
1.526 + }
1.527 + return totalMetrics;
1.528 +}
1.529 +
1.530 +void
1.531 +nsRenderingContext::DrawString(const char *aString, uint32_t aLength,
1.532 + nscoord aX, nscoord aY)
1.533 +{
1.534 + uint32_t maxChunkLength = GetMaxChunkLength();
1.535 + while (aLength > 0) {
1.536 + int32_t len = FindSafeLength(aString, aLength, maxChunkLength);
1.537 + mFontMetrics->DrawString(aString, len, aX, aY, this);
1.538 + aLength -= len;
1.539 +
1.540 + if (aLength > 0) {
1.541 + nscoord width = mFontMetrics->GetWidth(aString, len, this);
1.542 + aX += width;
1.543 + aString += len;
1.544 + }
1.545 + }
1.546 +}
1.547 +
1.548 +void
1.549 +nsRenderingContext::DrawString(const nsString& aString, nscoord aX, nscoord aY)
1.550 +{
1.551 + DrawString(aString.get(), aString.Length(), aX, aY);
1.552 +}
1.553 +
1.554 +void
1.555 +nsRenderingContext::DrawString(const char16_t *aString, uint32_t aLength,
1.556 + nscoord aX, nscoord aY)
1.557 +{
1.558 + uint32_t maxChunkLength = GetMaxChunkLength();
1.559 + if (aLength <= maxChunkLength) {
1.560 + mFontMetrics->DrawString(aString, aLength, aX, aY, this, this);
1.561 + return;
1.562 + }
1.563 +
1.564 + bool isRTL = mFontMetrics->GetTextRunRTL();
1.565 +
1.566 + // If we're drawing right to left, we must start at the end.
1.567 + if (isRTL) {
1.568 + aX += GetWidth(aString, aLength);
1.569 + }
1.570 +
1.571 + while (aLength > 0) {
1.572 + int32_t len = FindSafeLength(aString, aLength, maxChunkLength);
1.573 + nscoord width = mFontMetrics->GetWidth(aString, len, this);
1.574 + if (isRTL) {
1.575 + aX -= width;
1.576 + }
1.577 + mFontMetrics->DrawString(aString, len, aX, aY, this, this);
1.578 + if (!isRTL) {
1.579 + aX += width;
1.580 + }
1.581 + aLength -= len;
1.582 + aString += len;
1.583 + }
1.584 +}
