TexturePropertyAccessor.java

/*
 * Copyright (C) 2012 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 com.android.ide.eclipse.gltrace.state.transforms;

import com.android.ide.eclipse.gltrace.state.GLIntegerProperty;
import com.android.ide.eclipse.gltrace.state.GLStateType;
import com.android.ide.eclipse.gltrace.state.IGLProperty;

/**
 * The {@link TexturePropertyAccessor} provides the ability to access a
 * texture property. Texture properties are accessed by first identifying the active
 * texture unit ({@link GLStateType#ACTIVE_TEXTURE_UNIT}), and then identifying the texture
 * that is bound to that unit.
 */
public class TexturePropertyAccessor implements IGLPropertyAccessor {
    private final int mContextId;
    private final GLStateType mTargetUnitType;
    private final int mMipmapLevel;
    private final GLStateType mTextureType;
    private TextureUnitPropertyAccessor mTextureUnitPropertyAccessor;

    public TexturePropertyAccessor(int contextId, GLStateType textureUnitTarget, int level,
            GLStateType textureTargetName) {
        mContextId = contextId;
        mTargetUnitType = textureUnitTarget;
        mMipmapLevel = level;
        mTextureType = textureTargetName;
        mTextureUnitPropertyAccessor = new TextureUnitPropertyAccessor(mContextId,
                mTargetUnitType);
    }

    public TexturePropertyAccessor(int contextId, GLStateType textureUnitTarget,
            GLStateType textureTargetName) {
        this(contextId, textureUnitTarget, -1, textureTargetName);
    }

    @Override
    public IGLProperty getProperty(IGLProperty state) {
        // identify the texture that is bound in the current active texture unit
        IGLProperty targetTexture = mTextureUnitPropertyAccessor.getProperty(state);
        if (!(targetTexture instanceof GLIntegerProperty)) {
            return null;
        }
        Integer textureId = (Integer) targetTexture.getValue();

        // now extract the required property from the selected texture
        IGLPropertyAccessor textureAccessor;
        if (mMipmapLevel >= 0) {
            textureAccessor = GLPropertyAccessor.makeAccessor(mContextId,
                    GLStateType.TEXTURE_STATE,
                    GLStateType.TEXTURES,
                    textureId,
                    GLStateType.TEXTURE_MIPMAPS,
                    Integer.valueOf(mMipmapLevel),
                    mTextureType);
        } else {
            textureAccessor = GLPropertyAccessor.makeAccessor(mContextId,
                    GLStateType.TEXTURE_STATE,
                    GLStateType.TEXTURES,
                    textureId,
                    mTextureType);
        }

        return textureAccessor.getProperty(state);
    }

    @Override
    public String getPath() {
        return String.format("TEXTURE_STATE/TEXTURES/${activeTexture}/%s", mTextureType);
    }

}