libs/hwui/Matrix.cpp

/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#define LOG_TAG "OpenGLRenderer"

#include <math.h>
#include <stdlib.h>
#include <string.h>

#include <utils/Log.h>

#include <SkMatrix.h>

#include "Matrix.h"

namespace android {
namespace uirenderer {

void Matrix4::loadIdentity() {
    data[kScaleX]       = 1.0f;
    data[kSkewY]        = 0.0f;
    data[2]             = 0.0f;
    data[kPerspective0] = 0.0f;

    data[kSkewX]        = 0.0f;
    data[kScaleY]       = 1.0f;
    data[6]             = 0.0f;
    data[kPerspective1] = 0.0f;

    data[8]             = 0.0f;
    data[9]             = 0.0f;
    data[kScaleZ]       = 1.0f;
    data[11]            = 0.0f;

    data[kTranslateX]   = 0.0f;
    data[kTranslateY]   = 0.0f;
    data[kTranslateZ]   = 0.0f;
    data[kPerspective2] = 1.0f;

    mSimpleMatrix = true;
}

#define EPSILON 0.00001f
#define almost(u, v) (fabs((u) - (v)) < EPSILON)

bool Matrix4::changesBounds() {
    return !(almost(data[0], 1.0f) && almost(data[1], 0.0f) && almost(data[2], 0.0f) &&
             almost(data[4], 0.0f) && almost(data[5], 1.0f) && almost(data[6], 0.0f) &&
             almost(data[8], 0.0f) && almost(data[9], 0.0f) && almost(data[10], 1.0f));
}

void Matrix4::load(const float* v) {
    memcpy(data, v, sizeof(data));
    mSimpleMatrix = false;
}

void Matrix4::load(const Matrix4& v) {
    memcpy(data, v.data, sizeof(data));
    mSimpleMatrix = v.mSimpleMatrix;
}

void Matrix4::load(const SkMatrix& v) {
    memset(data, 0, sizeof(data));

    data[kScaleX]     = v[SkMatrix::kMScaleX];
    data[kSkewX]      = v[SkMatrix::kMSkewX];
    data[kTranslateX] = v[SkMatrix::kMTransX];

    data[kSkewY]      = v[SkMatrix::kMSkewY];
    data[kScaleY]     = v[SkMatrix::kMScaleY];
    data[kTranslateY] = v[SkMatrix::kMTransY];

    data[kPerspective0]  = v[SkMatrix::kMPersp0];
    data[kPerspective1]  = v[SkMatrix::kMPersp1];
    data[kPerspective2]  = v[SkMatrix::kMPersp2];

    data[kScaleZ] = 1.0f;

    mSimpleMatrix = (v.getType() <= SkMatrix::kScale_Mask);
}

void Matrix4::copyTo(SkMatrix& v) const {
    v.reset();

    v.set(SkMatrix::kMScaleX, data[kScaleX]);
    v.set(SkMatrix::kMSkewX,  data[kSkewX]);
    v.set(SkMatrix::kMTransX, data[kTranslateX]);

    v.set(SkMatrix::kMSkewY,  data[kSkewY]);
    v.set(SkMatrix::kMScaleY, data[kScaleY]);
    v.set(SkMatrix::kMTransY, data[kTranslateY]);

    v.set(SkMatrix::kMPersp0, data[kPerspective0]);
    v.set(SkMatrix::kMPersp1, data[kPerspective1]);
    v.set(SkMatrix::kMPersp2, data[kPerspective2]);
}

void Matrix4::loadInverse(const Matrix4& v) {
    double scale = 1.0 /
            (v.data[kScaleX] * ((double) v.data[kScaleY]  * v.data[kPerspective2] -
                    (double) v.data[kTranslateY] * v.data[kPerspective1]) +
             v.data[kSkewX] * ((double) v.data[kTranslateY] * v.data[kPerspective0] -
                     (double) v.data[kSkewY] * v.data[kPerspective2]) +
             v.data[kTranslateX] * ((double) v.data[kSkewY] * v.data[kPerspective1] -
                     (double) v.data[kScaleY] * v.data[kPerspective0]));

    data[kScaleX] = (v.data[kScaleY] * v.data[kPerspective2] -
            v.data[kTranslateY] * v.data[kPerspective1])  * scale;
    data[kSkewX] = (v.data[kTranslateX] * v.data[kPerspective1] -
            v.data[kSkewX]  * v.data[kPerspective2]) * scale;
    data[kTranslateX] = (v.data[kSkewX] * v.data[kTranslateY] -
            v.data[kTranslateX] * v.data[kScaleY])  * scale;

    data[kSkewY] = (v.data[kTranslateY] * v.data[kPerspective0] -
            v.data[kSkewY]  * v.data[kPerspective2]) * scale;
    data[kScaleY] = (v.data[kScaleX] * v.data[kPerspective2] -
            v.data[kTranslateX] * v.data[kPerspective0])  * scale;
    data[kTranslateY] = (v.data[kTranslateX] * v.data[kSkewY] -
            v.data[kScaleX]  * v.data[kTranslateY]) * scale;

    data[kPerspective0] = (v.data[kSkewY] * v.data[kPerspective1] -
            v.data[kScaleY] * v.data[kPerspective0]) * scale;
    data[kPerspective1] = (v.data[kSkewX] * v.data[kPerspective0] -
            v.data[kScaleX] * v.data[kPerspective1]) * scale;
    data[kPerspective2] = (v.data[kScaleX] * v.data[kScaleY] -
            v.data[kSkewX] * v.data[kSkewY]) * scale;

    mSimpleMatrix = v.mSimpleMatrix;
}

void Matrix4::copyTo(float* v) const {
    memcpy(v, data, sizeof(data));
}

float Matrix4::getTranslateX() {
    return data[kTranslateX];
}

float Matrix4::getTranslateY() {
    return data[kTranslateY];
}

void Matrix4::multiply(float v) {
    for (int i = 0; i < 16; i++) {
        data[i] *= v;
    }
}

void Matrix4::loadTranslate(float x, float y, float z) {
    loadIdentity();
    data[kTranslateX] = x;
    data[kTranslateY] = y;
    data[kTranslateZ] = z;
}

void Matrix4::loadScale(float sx, float sy, float sz) {
    loadIdentity();
    data[kScaleX] = sx;
    data[kScaleY] = sy;
    data[kScaleZ] = sz;
}

void Matrix4::loadRotate(float angle, float x, float y, float z) {
    data[kPerspective0]  = 0.0f;
    data[kPerspective1]  = 0.0f;
    data[11]             = 0.0f;
    data[kTranslateX]    = 0.0f;
    data[kTranslateY]    = 0.0f;
    data[kTranslateZ]    = 0.0f;
    data[kPerspective2]  = 1.0f;

    angle *= float(M_PI / 180.0f);
    float c = cosf(angle);
    float s = sinf(angle);

    const float length = sqrtf(x * x + y * y + z * z);
    float recipLen = 1.0f / length;
    x *= recipLen;
    y *= recipLen;
    z *= recipLen;

    const float nc = 1.0f - c;
    const float xy = x * y;
    const float yz = y * z;
    const float zx = z * x;
    const float xs = x * s;
    const float ys = y * s;
    const float zs = z * s;

    data[kScaleX] = x * x * nc +  c;
    data[kSkewX]  =    xy * nc - zs;
    data[8]       =    zx * nc + ys;
    data[kSkewY]  =    xy * nc + zs;
    data[kScaleY] = y * y * nc +  c;
    data[9]       =    yz * nc - xs;
    data[2]       =    zx * nc - ys;
    data[6]       =    yz * nc + xs;
    data[kScaleZ] = z * z * nc +  c;

    mSimpleMatrix = false;
}

void Matrix4::loadMultiply(const Matrix4& u, const Matrix4& v) {
    for (int i = 0 ; i < 4 ; i++) {
        float x = 0;
        float y = 0;
        float z = 0;
        float w = 0;

        for (int j = 0 ; j < 4 ; j++) {
            const float e = v.get(i, j);
            x += u.get(j, 0) * e;
            y += u.get(j, 1) * e;
            z += u.get(j, 2) * e;
            w += u.get(j, 3) * e;
        }

        set(i, 0, x);
        set(i, 1, y);
        set(i, 2, z);
        set(i, 3, w);
    }

    mSimpleMatrix = u.mSimpleMatrix && v.mSimpleMatrix;
}

void Matrix4::loadOrtho(float left, float right, float bottom, float top, float near, float far) {
    loadIdentity();
    data[kScaleX] = 2.0f / (right - left);
    data[kScaleY] = 2.0f / (top - bottom);
    data[kScaleZ] = -2.0f / (far - near);
    data[kTranslateX] = -(right + left) / (right - left);
    data[kTranslateY] = -(top + bottom) / (top - bottom);
    data[kTranslateZ] = -(far + near) / (far - near);
}

#define MUL_ADD_STORE(a, b, c) a = (a) * (b) + (c)

void Matrix4::mapPoint(float& x, float& y) const {
    if (mSimpleMatrix) {
        MUL_ADD_STORE(x, data[kScaleX], data[kTranslateX]);
        MUL_ADD_STORE(y, data[kScaleY], data[kTranslateY]);
        return;
    }

    float dx = x * data[kScaleX] + y * data[kSkewX] + data[kTranslateX];
    float dy = x * data[kSkewY] + y * data[kScaleY] + data[kTranslateY];
    float dz = x * data[kPerspective0] + y * data[kPerspective1] + data[kPerspective2];
    if (dz) dz = 1.0f / dz;

    x = dx * dz;
    y = dy * dz;
}

void Matrix4::mapRect(Rect& r) const {
    if (mSimpleMatrix) {
        MUL_ADD_STORE(r.left, data[kScaleX], data[kTranslateX]);
        MUL_ADD_STORE(r.right, data[kScaleX], data[kTranslateX]);
        MUL_ADD_STORE(r.top, data[kScaleY], data[kTranslateY]);
        MUL_ADD_STORE(r.bottom, data[kScaleY], data[kTranslateY]);
        return;
    }

    float vertices[] = {
        r.left, r.top,
        r.right, r.top,
        r.right, r.bottom,
        r.left, r.bottom
    };

    float x, y, z;

    for (int i = 0; i < 8; i+= 2) {
        float px = vertices[i];
        float py = vertices[i + 1];

        x = px * data[kScaleX] + py * data[kSkewX] + data[kTranslateX];
        y = px * data[kSkewY] + py * data[kScaleY] + data[kTranslateY];
        z = px * data[kPerspective0] + py * data[kPerspective1] + data[kPerspective2];
        if (z) z = 1.0f / z;

        vertices[i] = x * z;
        vertices[i + 1] = y * z;
    }

    r.left = r.right = vertices[0];
    r.top = r.bottom = vertices[1];

    for (int i = 2; i < 8; i += 2) {
        x = vertices[i];
        y = vertices[i + 1];

        if (x < r.left) r.left = x;
        else if (x > r.right) r.right = x;
        if (y < r.top) r.top = y;
        else if (y > r.bottom) r.bottom = y;
    }
}

void Matrix4::dump() const {
    LOGD("Matrix4[simple=%d", mSimpleMatrix);
    LOGD("  %f %f %f %f", data[kScaleX], data[kSkewX], data[8], data[kTranslateX]);
    LOGD("  %f %f %f %f", data[kSkewY], data[kScaleY], data[9], data[kTranslateY]);
    LOGD("  %f %f %f %f", data[2], data[6], data[kScaleZ], data[kTranslateZ]);
    LOGD("  %f %f %f %f", data[kPerspective0], data[kPerspective1], data[11], data[kPerspective2]);
    LOGD("]");
}

}; // namespace uirenderer
}; // namespace android