nsStyleTransformMatrix.cpp
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */
/*
* A class used for intermediate representations of the -moz-transform property.
*/
#include "nsStyleTransformMatrix.h"
#include "nsAutoPtr.h"
#include "nsCSSValue.h"
#include "nsStyleContext.h"
#include "nsPresContext.h"
#include "nsRuleNode.h"
#include "nsCSSKeywords.h"
#include "nsMathUtils.h"
#include "CSSCalc.h"
#include "nsStyleAnimation.h"
namespace css = mozilla::css;
namespace nsStyleTransformMatrix {
/* Note on floating point precision: The transform matrix is an array
* of single precision 'float's, and so are most of the input values
* we get from the style system, but intermediate calculations
* involving angles need to be done in 'double'.
*/
/* Force small values to zero. We do this to avoid having sin(360deg)
* evaluate to a tiny but nonzero value.
*/
static double FlushToZero(double aVal)
{
if (-FLT_EPSILON < aVal && aVal < FLT_EPSILON)
return 0.0f;
else
return aVal;
}
/* Helper function to fill in an nscoord with the specified nsCSSValue. */
static nscoord CalcLength(const nsCSSValue &aValue,
nsStyleContext* aContext,
nsPresContext* aPresContext,
bool &aCanStoreInRuleTree)
{
if (aValue.GetUnit() == eCSSUnit_Pixel ||
aValue.GetUnit() == eCSSUnit_Number) {
// Handle this here (even though nsRuleNode::CalcLength handles it
// fine) so that callers are allowed to pass a null style context
// and pres context to SetToTransformFunction if they know (as
// nsStyleAnimation does) that all lengths within the transform
// function have already been computed to pixels and percents.
//
// Raw numbers are treated as being pixels.
return nsPresContext::CSSPixelsToAppUnits(aValue.GetFloatValue());
}
return nsRuleNode::CalcLength(aValue, aContext, aPresContext,
aCanStoreInRuleTree);
}
static float
ProcessTranslatePart(const nsCSSValue& aValue,
nsStyleContext* aContext,
nsPresContext* aPresContext,
bool& aCanStoreInRuleTree,
nscoord aSize, float aAppUnitsPerMatrixUnit)
{
nscoord offset = 0;
float percent = 0.0f;
if (aValue.GetUnit() == eCSSUnit_Percent) {
percent = aValue.GetPercentValue();
} else if (aValue.IsCalcUnit()) {
nsRuleNode::ComputedCalc result =
nsRuleNode::SpecifiedCalcToComputedCalc(aValue, aContext, aPresContext,
aCanStoreInRuleTree);
percent = result.mPercent;
offset = result.mLength;
} else {
offset = CalcLength(aValue, aContext, aPresContext,
aCanStoreInRuleTree);
}
return (percent * NSAppUnitsToFloatPixels(aSize, aAppUnitsPerMatrixUnit)) +
NSAppUnitsToFloatPixels(offset, aAppUnitsPerMatrixUnit);
}
/**
* Helper functions to process all the transformation function types.
*
* These take a matrix parameter to accumulate the current matrix.
*/
/* Helper function to process a matrix entry. */
static void
ProcessMatrix(gfx3DMatrix& aMatrix,
const nsCSSValue::Array* aData,
nsStyleContext* aContext,
nsPresContext* aPresContext,
bool& aCanStoreInRuleTree,
nsRect& aBounds, float aAppUnitsPerMatrixUnit)
{
NS_PRECONDITION(aData->Count() == 7, "Invalid array!");
gfxMatrix result;
/* Take the first four elements out of the array as floats and store
* them.
*/
result.xx = aData->Item(1).GetFloatValue();
result.yx = aData->Item(2).GetFloatValue();
result.xy = aData->Item(3).GetFloatValue();
result.yy = aData->Item(4).GetFloatValue();
/* The last two elements have their length parts stored in aDelta
* and their percent parts stored in aX[0] and aY[1].
*/
result.x0 = ProcessTranslatePart(aData->Item(5),
aContext, aPresContext, aCanStoreInRuleTree,
aBounds.Width(), aAppUnitsPerMatrixUnit);
result.y0 = ProcessTranslatePart(aData->Item(6),
aContext, aPresContext, aCanStoreInRuleTree,
aBounds.Height(), aAppUnitsPerMatrixUnit);
aMatrix.PreMultiply(result);
}
static void
ProcessMatrix3D(gfx3DMatrix& aMatrix,
const nsCSSValue::Array* aData,
nsStyleContext* aContext,
nsPresContext* aPresContext,
bool& aCanStoreInRuleTree,
nsRect& aBounds, float aAppUnitsPerMatrixUnit)
{
NS_PRECONDITION(aData->Count() == 17, "Invalid array!");
gfx3DMatrix temp;
temp._11 = aData->Item(1).GetFloatValue();
temp._12 = aData->Item(2).GetFloatValue();
temp._13 = aData->Item(3).GetFloatValue();
temp._14 = aData->Item(4).GetFloatValue();
temp._21 = aData->Item(5).GetFloatValue();
temp._22 = aData->Item(6).GetFloatValue();
temp._23 = aData->Item(7).GetFloatValue();
temp._24 = aData->Item(8).GetFloatValue();
temp._31 = aData->Item(9).GetFloatValue();
temp._32 = aData->Item(10).GetFloatValue();
temp._33 = aData->Item(11).GetFloatValue();
temp._34 = aData->Item(12).GetFloatValue();
temp._44 = aData->Item(16).GetFloatValue();
temp._41 = ProcessTranslatePart(aData->Item(13),
aContext, aPresContext, aCanStoreInRuleTree,
aBounds.Width(), aAppUnitsPerMatrixUnit);
temp._42 = ProcessTranslatePart(aData->Item(14),
aContext, aPresContext, aCanStoreInRuleTree,
aBounds.Height(), aAppUnitsPerMatrixUnit);
temp._43 = ProcessTranslatePart(aData->Item(15),
aContext, aPresContext, aCanStoreInRuleTree,
aBounds.Height(), aAppUnitsPerMatrixUnit);
aMatrix.PreMultiply(temp);
}
/* Helper function to process two matrices that we need to interpolate between */
static void
ProcessInterpolateMatrix(gfx3DMatrix& aMatrix,
const nsCSSValue::Array* aData,
nsStyleContext* aContext,
nsPresContext* aPresContext,
bool& aCanStoreInRuleTree,
nsRect& aBounds, float aAppUnitsPerMatrixUnit)
{
NS_PRECONDITION(aData->Count() == 4, "Invalid array!");
gfx3DMatrix matrix1, matrix2;
if (aData->Item(1).GetUnit() == eCSSUnit_List) {
matrix1 = nsStyleTransformMatrix::ReadTransforms(aData->Item(1).GetListValue(),
aContext, aPresContext,
aCanStoreInRuleTree,
aBounds, aAppUnitsPerMatrixUnit);
}
if (aData->Item(2).GetUnit() == eCSSUnit_List) {
matrix2 = ReadTransforms(aData->Item(2).GetListValue(),
aContext, aPresContext,
aCanStoreInRuleTree,
aBounds, aAppUnitsPerMatrixUnit);
}
double progress = aData->Item(3).GetPercentValue();
aMatrix = nsStyleAnimation::InterpolateTransformMatrix(matrix1, matrix2, progress) * aMatrix;
}
/* Helper function to process a translatex function. */
static void
ProcessTranslateX(gfx3DMatrix& aMatrix,
const nsCSSValue::Array* aData,
nsStyleContext* aContext,
nsPresContext* aPresContext,
bool& aCanStoreInRuleTree,
nsRect& aBounds, float aAppUnitsPerMatrixUnit)
{
NS_PRECONDITION(aData->Count() == 2, "Invalid array!");
gfxPoint3D temp;
temp.x = ProcessTranslatePart(aData->Item(1),
aContext, aPresContext, aCanStoreInRuleTree,
aBounds.Width(), aAppUnitsPerMatrixUnit);
aMatrix.Translate(temp);
}
/* Helper function to process a translatey function. */
static void
ProcessTranslateY(gfx3DMatrix& aMatrix,
const nsCSSValue::Array* aData,
nsStyleContext* aContext,
nsPresContext* aPresContext,
bool& aCanStoreInRuleTree,
nsRect& aBounds, float aAppUnitsPerMatrixUnit)
{
NS_PRECONDITION(aData->Count() == 2, "Invalid array!");
gfxPoint3D temp;
temp.y = ProcessTranslatePart(aData->Item(1),
aContext, aPresContext, aCanStoreInRuleTree,
aBounds.Height(), aAppUnitsPerMatrixUnit);
aMatrix.Translate(temp);
}
static void
ProcessTranslateZ(gfx3DMatrix& aMatrix,
const nsCSSValue::Array* aData,
nsStyleContext* aContext,
nsPresContext* aPresContext,
bool& aCanStoreInRuleTree,
float aAppUnitsPerMatrixUnit)
{
NS_PRECONDITION(aData->Count() == 2, "Invalid array!");
gfxPoint3D temp;
temp.z = ProcessTranslatePart(aData->Item(1),
aContext, aPresContext, aCanStoreInRuleTree,
0, aAppUnitsPerMatrixUnit);
aMatrix.Translate(temp);
}
/* Helper function to process a translate function. */
static void
ProcessTranslate(gfx3DMatrix& aMatrix,
const nsCSSValue::Array* aData,
nsStyleContext* aContext,
nsPresContext* aPresContext,
bool& aCanStoreInRuleTree,
nsRect& aBounds, float aAppUnitsPerMatrixUnit)
{
NS_PRECONDITION(aData->Count() == 2 || aData->Count() == 3, "Invalid array!");
gfxPoint3D temp;
temp.x = ProcessTranslatePart(aData->Item(1),
aContext, aPresContext, aCanStoreInRuleTree,
aBounds.Width(), aAppUnitsPerMatrixUnit);
/* If we read in a Y component, set it appropriately */
if (aData->Count() == 3) {
temp.y = ProcessTranslatePart(aData->Item(2),
aContext, aPresContext, aCanStoreInRuleTree,
aBounds.Height(), aAppUnitsPerMatrixUnit);
}
aMatrix.Translate(temp);
}
static void
ProcessTranslate3D(gfx3DMatrix& aMatrix,
const nsCSSValue::Array* aData,
nsStyleContext* aContext,
nsPresContext* aPresContext,
bool& aCanStoreInRuleTree,
nsRect& aBounds, float aAppUnitsPerMatrixUnit)
{
NS_PRECONDITION(aData->Count() == 4, "Invalid array!");
gfxPoint3D temp;
temp.x = ProcessTranslatePart(aData->Item(1),
aContext, aPresContext, aCanStoreInRuleTree,
aBounds.Width(), aAppUnitsPerMatrixUnit);
temp.y = ProcessTranslatePart(aData->Item(2),
aContext, aPresContext, aCanStoreInRuleTree,
aBounds.Height(), aAppUnitsPerMatrixUnit);
temp.z = ProcessTranslatePart(aData->Item(3),
aContext, aPresContext, aCanStoreInRuleTree,
0, aAppUnitsPerMatrixUnit);
aMatrix.Translate(temp);
}
/* Helper function to set up a scale matrix. */
static void
ProcessScaleHelper(gfx3DMatrix& aMatrix,
float aXScale,
float aYScale,
float aZScale)
{
aMatrix.Scale(aXScale, aYScale, aZScale);
}
/* Process a scalex function. */
static void
ProcessScaleX(gfx3DMatrix& aMatrix, const nsCSSValue::Array* aData)
{
NS_PRECONDITION(aData->Count() == 2, "Bad array!");
ProcessScaleHelper(aMatrix, aData->Item(1).GetFloatValue(), 1.0f, 1.0f);
}
/* Process a scaley function. */
static void
ProcessScaleY(gfx3DMatrix& aMatrix, const nsCSSValue::Array* aData)
{
NS_PRECONDITION(aData->Count() == 2, "Bad array!");
ProcessScaleHelper(aMatrix, 1.0f, aData->Item(1).GetFloatValue(), 1.0f);
}
static void
ProcessScaleZ(gfx3DMatrix& aMatrix, const nsCSSValue::Array* aData)
{
NS_PRECONDITION(aData->Count() == 2, "Bad array!");
ProcessScaleHelper(aMatrix, 1.0f, 1.0f, aData->Item(1).GetFloatValue());
}
static void
ProcessScale3D(gfx3DMatrix& aMatrix, const nsCSSValue::Array* aData)
{
NS_PRECONDITION(aData->Count() == 4, "Bad array!");
ProcessScaleHelper(aMatrix,
aData->Item(1).GetFloatValue(),
aData->Item(2).GetFloatValue(),
aData->Item(3).GetFloatValue());
}
/* Process a scale function. */
static void
ProcessScale(gfx3DMatrix& aMatrix, const nsCSSValue::Array* aData)
{
NS_PRECONDITION(aData->Count() == 2 || aData->Count() == 3, "Bad array!");
/* We either have one element or two. If we have one, it's for both X and Y.
* Otherwise it's one for each.
*/
const nsCSSValue& scaleX = aData->Item(1);
const nsCSSValue& scaleY = (aData->Count() == 2 ? scaleX :
aData->Item(2));
ProcessScaleHelper(aMatrix,
scaleX.GetFloatValue(),
scaleY.GetFloatValue(),
1.0f);
}
/* Helper function that, given a set of angles, constructs the appropriate
* skew matrix.
*/
static void
ProcessSkewHelper(gfx3DMatrix& aMatrix, double aXAngle, double aYAngle)
{
aMatrix.SkewXY(aXAngle, aYAngle);
}
/* Function that converts a skewx transform into a matrix. */
static void
ProcessSkewX(gfx3DMatrix& aMatrix, const nsCSSValue::Array* aData)
{
NS_ASSERTION(aData->Count() == 2, "Bad array!");
ProcessSkewHelper(aMatrix, aData->Item(1).GetAngleValueInRadians(), 0.0);
}
/* Function that converts a skewy transform into a matrix. */
static void
ProcessSkewY(gfx3DMatrix& aMatrix, const nsCSSValue::Array* aData)
{
NS_ASSERTION(aData->Count() == 2, "Bad array!");
ProcessSkewHelper(aMatrix, 0.0, aData->Item(1).GetAngleValueInRadians());
}
/* Function that converts a skew transform into a matrix. */
static void
ProcessSkew(gfx3DMatrix& aMatrix, const nsCSSValue::Array* aData)
{
NS_ASSERTION(aData->Count() == 2 || aData->Count() == 3, "Bad array!");
double xSkew = aData->Item(1).GetAngleValueInRadians();
double ySkew = (aData->Count() == 2
? 0.0 : aData->Item(2).GetAngleValueInRadians());
ProcessSkewHelper(aMatrix, xSkew, ySkew);
}
/* Function that converts a rotate transform into a matrix. */
static void
ProcessRotateZ(gfx3DMatrix& aMatrix, const nsCSSValue::Array* aData)
{
NS_PRECONDITION(aData->Count() == 2, "Invalid array!");
double theta = aData->Item(1).GetAngleValueInRadians();
aMatrix.RotateZ(theta);
}
static void
ProcessRotateX(gfx3DMatrix& aMatrix, const nsCSSValue::Array* aData)
{
NS_PRECONDITION(aData->Count() == 2, "Invalid array!");
double theta = aData->Item(1).GetAngleValueInRadians();
aMatrix.RotateX(theta);
}
static void
ProcessRotateY(gfx3DMatrix& aMatrix, const nsCSSValue::Array* aData)
{
NS_PRECONDITION(aData->Count() == 2, "Invalid array!");
double theta = aData->Item(1).GetAngleValueInRadians();
aMatrix.RotateY(theta);
}
static void
ProcessRotate3D(gfx3DMatrix& aMatrix, const nsCSSValue::Array* aData)
{
NS_PRECONDITION(aData->Count() == 5, "Invalid array!");
/* We want our matrix to look like this:
* | 1 + (1-cos(angle))*(x*x-1) -z*sin(angle)+(1-cos(angle))*x*y y*sin(angle)+(1-cos(angle))*x*z 0 |
* | z*sin(angle)+(1-cos(angle))*x*y 1 + (1-cos(angle))*(y*y-1) -x*sin(angle)+(1-cos(angle))*y*z 0 |
* | -y*sin(angle)+(1-cos(angle))*x*z x*sin(angle)+(1-cos(angle))*y*z 1 + (1-cos(angle))*(z*z-1) 0 |
* | 0 0 0 1 |
* (see http://www.w3.org/TR/css3-3d-transforms/#transform-functions)
*/
/* The current spec specifies a matrix that rotates in the wrong direction. For now we just negate
* the angle provided to get the correct rotation direction until the spec is updated.
* See bug 704468.
*/
double theta = -aData->Item(4).GetAngleValueInRadians();
float cosTheta = FlushToZero(cos(theta));
float sinTheta = FlushToZero(sin(theta));
float x = aData->Item(1).GetFloatValue();
float y = aData->Item(2).GetFloatValue();
float z = aData->Item(3).GetFloatValue();
/* Normalize [x,y,z] */
float length = sqrt(x*x + y*y + z*z);
if (length == 0.0) {
return;
}
x /= length;
y /= length;
z /= length;
gfx3DMatrix temp;
/* Create our matrix */
temp._11 = 1 + (1 - cosTheta) * (x * x - 1);
temp._12 = -z * sinTheta + (1 - cosTheta) * x * y;
temp._13 = y * sinTheta + (1 - cosTheta) * x * z;
temp._14 = 0.0f;
temp._21 = z * sinTheta + (1 - cosTheta) * x * y;
temp._22 = 1 + (1 - cosTheta) * (y * y - 1);
temp._23 = -x * sinTheta + (1 - cosTheta) * y * z;
temp._24 = 0.0f;
temp._31 = -y * sinTheta + (1 - cosTheta) * x * z;
temp._32 = x * sinTheta + (1 - cosTheta) * y * z;
temp._33 = 1 + (1 - cosTheta) * (z * z - 1);
temp._34 = 0.0f;
temp._41 = 0.0f;
temp._42 = 0.0f;
temp._43 = 0.0f;
temp._44 = 1.0f;
aMatrix = temp * aMatrix;
}
static void
ProcessPerspective(gfx3DMatrix& aMatrix,
const nsCSSValue::Array* aData,
nsStyleContext *aContext,
nsPresContext *aPresContext,
bool &aCanStoreInRuleTree,
float aAppUnitsPerMatrixUnit)
{
NS_PRECONDITION(aData->Count() == 2, "Invalid array!");
float depth = ProcessTranslatePart(aData->Item(1), aContext,
aPresContext, aCanStoreInRuleTree,
0, aAppUnitsPerMatrixUnit);
aMatrix.Perspective(depth);
}
/**
* SetToTransformFunction is essentially a giant switch statement that fans
* out to many smaller helper functions.
*/
static void
MatrixForTransformFunction(gfx3DMatrix& aMatrix,
const nsCSSValue::Array * aData,
nsStyleContext* aContext,
nsPresContext* aPresContext,
bool& aCanStoreInRuleTree,
nsRect& aBounds,
float aAppUnitsPerMatrixUnit)
{
NS_PRECONDITION(aData, "Why did you want to get data from a null array?");
// It's OK if aContext and aPresContext are null if the caller already
// knows that all length units have been converted to pixels (as
// nsStyleAnimation does).
/* Get the keyword for the transform. */
switch (TransformFunctionOf(aData)) {
case eCSSKeyword_translatex:
ProcessTranslateX(aMatrix, aData, aContext, aPresContext,
aCanStoreInRuleTree, aBounds, aAppUnitsPerMatrixUnit);
break;
case eCSSKeyword_translatey:
ProcessTranslateY(aMatrix, aData, aContext, aPresContext,
aCanStoreInRuleTree, aBounds, aAppUnitsPerMatrixUnit);
break;
case eCSSKeyword_translatez:
ProcessTranslateZ(aMatrix, aData, aContext, aPresContext,
aCanStoreInRuleTree, aAppUnitsPerMatrixUnit);
break;
case eCSSKeyword_translate:
ProcessTranslate(aMatrix, aData, aContext, aPresContext,
aCanStoreInRuleTree, aBounds, aAppUnitsPerMatrixUnit);
break;
case eCSSKeyword_translate3d:
ProcessTranslate3D(aMatrix, aData, aContext, aPresContext,
aCanStoreInRuleTree, aBounds, aAppUnitsPerMatrixUnit);
break;
case eCSSKeyword_scalex:
ProcessScaleX(aMatrix, aData);
break;
case eCSSKeyword_scaley:
ProcessScaleY(aMatrix, aData);
break;
case eCSSKeyword_scalez:
ProcessScaleZ(aMatrix, aData);
break;
case eCSSKeyword_scale:
ProcessScale(aMatrix, aData);
break;
case eCSSKeyword_scale3d:
ProcessScale3D(aMatrix, aData);
break;
case eCSSKeyword_skewx:
ProcessSkewX(aMatrix, aData);
break;
case eCSSKeyword_skewy:
ProcessSkewY(aMatrix, aData);
break;
case eCSSKeyword_skew:
ProcessSkew(aMatrix, aData);
break;
case eCSSKeyword_rotatex:
ProcessRotateX(aMatrix, aData);
break;
case eCSSKeyword_rotatey:
ProcessRotateY(aMatrix, aData);
break;
case eCSSKeyword_rotatez:
case eCSSKeyword_rotate:
ProcessRotateZ(aMatrix, aData);
break;
case eCSSKeyword_rotate3d:
ProcessRotate3D(aMatrix, aData);
break;
case eCSSKeyword_matrix:
ProcessMatrix(aMatrix, aData, aContext, aPresContext,
aCanStoreInRuleTree, aBounds, aAppUnitsPerMatrixUnit);
break;
case eCSSKeyword_matrix3d:
ProcessMatrix3D(aMatrix, aData, aContext, aPresContext,
aCanStoreInRuleTree, aBounds, aAppUnitsPerMatrixUnit);
break;
case eCSSKeyword_interpolatematrix:
ProcessInterpolateMatrix(aMatrix, aData, aContext, aPresContext,
aCanStoreInRuleTree, aBounds, aAppUnitsPerMatrixUnit);
break;
case eCSSKeyword_perspective:
ProcessPerspective(aMatrix, aData, aContext, aPresContext,
aCanStoreInRuleTree, aAppUnitsPerMatrixUnit);
break;
default:
NS_NOTREACHED("Unknown transform function!");
}
}
/**
* Return the transform function, as an nsCSSKeyword, for the given
* nsCSSValue::Array from a transform list.
*/
nsCSSKeyword
TransformFunctionOf(const nsCSSValue::Array* aData)
{
nsAutoString keyword;
aData->Item(0).GetStringValue(keyword);
return nsCSSKeywords::LookupKeyword(keyword);
}
gfx3DMatrix
ReadTransforms(const nsCSSValueList* aList,
nsStyleContext* aContext,
nsPresContext* aPresContext,
bool &aCanStoreInRuleTree,
nsRect& aBounds,
float aAppUnitsPerMatrixUnit)
{
gfx3DMatrix result;
for (const nsCSSValueList* curr = aList; curr != nsnull; curr = curr->mNext) {
const nsCSSValue &currElem = curr->mValue;
NS_ASSERTION(currElem.GetUnit() == eCSSUnit_Function,
"Stream should consist solely of functions!");
NS_ASSERTION(currElem.GetArrayValue()->Count() >= 1,
"Incoming function is too short!");
/* Read in a single transform matrix. */
MatrixForTransformFunction(result, currElem.GetArrayValue(), aContext,
aPresContext, aCanStoreInRuleTree,
aBounds, aAppUnitsPerMatrixUnit);
}
return result;
}
} // namespace nsStyleTransformMatrix
