/*
 * Copyright (C) 2009 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.
 */

package android.renderscript;

import java.lang.Math;
import android.util.Log;


public class ProgramVertexAlloc {
    public static final int MODELVIEW_OFFSET = 0;
    public static final int PROJECTION_OFFSET = 16;
    public static final int TEXTURE_OFFSET = 32;

    Matrix mModel;
    Matrix mProjection;
    Matrix mTexture;

    public RenderScript.Allocation mAlloc;

    public ProgramVertexAlloc(RenderScript rs) {
        mModel = new Matrix();
        mProjection = new Matrix();
        mTexture = new Matrix();

        mAlloc = rs.allocationCreatePredefSized(
            RenderScript.ElementPredefined.USER_FLOAT, 
            48);

        mAlloc.subData1D(MODELVIEW_OFFSET, 16, mModel.mMat);
        mAlloc.subData1D(PROJECTION_OFFSET, 16, mProjection.mMat);
        mAlloc.subData1D(TEXTURE_OFFSET, 16, mTexture.mMat);
    }

    public void loadModelview(Matrix m) {
        mModel = m;
        mAlloc.subData1D(MODELVIEW_OFFSET, 16, m.mMat);
    }

    public void loadProjection(Matrix m) {
        mProjection = m;
        mAlloc.subData1D(PROJECTION_OFFSET, 16, m.mMat);
    }

    public void loadTexture(Matrix m) {
        mTexture = m;
        mAlloc.subData1D(TEXTURE_OFFSET, 16, m.mMat);
    }

    public void setupOrthoWindow(int w, int h) {
        mProjection.loadOrtho(0,w, h,0, -1,1);
        mAlloc.subData1D(PROJECTION_OFFSET, 16, mProjection.mMat);
    }

    public void setupOrthoNormalized(int w, int h) {
        // range -1,1 in the narrow axis.
        if(w > h) {
            float aspect = ((float)w) / h;
            mProjection.loadOrtho(-aspect,aspect,  -1,1,  -1,1);
        } else {
            float aspect = ((float)h) / w;
            mProjection.loadOrtho(-1,1, -aspect,aspect,  -1,1);
        }
        mAlloc.subData1D(PROJECTION_OFFSET, 16, mProjection.mMat);
    }

    public void setupProjectionNormalized(int w, int h) {
        // range -1,1 in the narrow axis at z = 0.
        Matrix m1 = new Matrix();
        Matrix m2 = new Matrix();

        if(w > h) {
            float aspect = ((float)w) / h;
            m1.loadFrustum(-aspect,aspect,  -1,1,  1,100);
        } else {
            float aspect = ((float)h) / w;
            m1.loadFrustum(-1,1, -aspect,aspect, 1,100);
        }

        m2.loadRotate(180, 0, 1, 0);
        m1.loadMultiply(m1, m2);

        m2.loadScale(-2, 2, 1);
        m1.loadMultiply(m1, m2);

        m2.loadTranslate(0, 0, 2);
        m1.loadMultiply(m1, m2);

        mProjection = m1;
        mAlloc.subData1D(PROJECTION_OFFSET, 16, mProjection.mMat);
    }

}