Source/core/platform/graphics/filters/custom/CustomFilterGlobalContext.h

/*
 * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above
 *    copyright notice, this list of conditions and the following
 *    disclaimer.
 * 2. Redistributions in binary form must reproduce the above
 *    copyright notice, this list of conditions and the following
 *    disclaimer in the documentation and/or other materials
 *    provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER “AS IS” AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef CustomFilterGlobalContext_h
#define CustomFilterGlobalContext_h

#include "platform/graphics/angle/ANGLEPlatformBridge.h"
#include "platform/graphics/filters/custom/CustomFilterProgramInfo.h"
#include "wtf/HashMap.h"
#include "wtf/RefPtr.h"

namespace WebCore {

class CustomFilterValidatedProgram;
class GraphicsContext3D;

typedef HashMap<CustomFilterProgramInfo, CustomFilterValidatedProgram*> CustomFilterValidatedProgramsMap;

class CustomFilterGlobalContext {
public:
    CustomFilterGlobalContext();
    ~CustomFilterGlobalContext();

    GraphicsContext3D* context() const { return m_context.get(); }

    // CSS shaders not referenced from the CSS mix function should be validated just like regular WebGL shaders.
    // This ANGLE validator uses the SH_WEBGL_SPEC flag.
    ANGLEPlatformBridge* webglShaderValidator();

    // CSS shaders referenced from the CSS mix function should be validated slightly differently than WebGL shaders.
    // This ANGLE validator uses the SH_CSS_SHADERS_SPEC flag.
    // Under this flag, most notably:
    // - The "gl_FragColor" built-in is not available.
    // - Instead, the "css_MixColor" and "css_ColorMatrix" built-ins are available.
    // - The "css_" prefix is reserved.
    // - In the translated source that ANGLE returns, ANGLE renames the author's "main" function to "css_main".
    // The complete details are documented in ANGLE/ShaderLang.h.
    ANGLEPlatformBridge* mixShaderValidator();

    void prepareContextIfNeeded();

    PassRefPtr<CustomFilterValidatedProgram> getValidatedProgram(const CustomFilterProgramInfo&);
    void removeValidatedProgram(const CustomFilterValidatedProgram*);
private:
    static PassOwnPtr<ANGLEPlatformBridge> createShaderValidator(ShShaderSpec);

    RefPtr<GraphicsContext3D> m_context;
    OwnPtr<ANGLEPlatformBridge> m_webglShaderValidator;
    OwnPtr<ANGLEPlatformBridge> m_mixShaderValidator;
    CustomFilterValidatedProgramsMap m_programs;
};

} // namespace WebCore

#endif // CustomFilterGlobalContext_h