OpenSpace/modules/webbrowser/src/webrenderhandler.cpp

/*****************************************************************************************
 *                                                                                       *
 * OpenSpace                                                                             *
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 * Copyright (c) 2014-2018                                                               *
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#include <modules/webbrowser/include/webrenderhandler.h>

#include <ghoul/glm.h>
#include <fmt/format.h>
#include <ghoul/logging/logmanager.h>

namespace openspace {

void WebRenderHandler::reshape(int w, int h) {
    if (w == _windowSize.x && h == _windowSize.y) {
        return;
    }
    _windowSize = glm::ivec2(w, h);
    _needsRepaint = true;
}

bool WebRenderHandler::GetViewRect(CefRefPtr<CefBrowser> browser, CefRect& rect) {
    rect = CefRect(0, 0, _windowSize.x, _windowSize.y);
    return true;
}

void WebRenderHandler::OnPaint(CefRefPtr<CefBrowser> browser,
                               CefRenderHandler::PaintElementType,
                               const CefRenderHandler::RectList& dirtyRects,
                               const void* buffer, int w, int h)
{
    const size_t bufferSize = static_cast<size_t>(w * h);

    glm::ivec2 upperUpdatingRectBound = glm::ivec2(0, 0);
    glm::ivec2 lowerUpdatingRectBound = glm::ivec2(w, h);

    if (_needsRepaint || _browserBuffer.size() != bufferSize) {
        _browserBufferSize = glm::ivec2(w, h);
        _browserBuffer.resize(w * h, Pixel(0));
        _textureSizeIsDirty = true;
        _upperDirtyRectBound = upperUpdatingRectBound = glm::ivec2(w, h);
        _lowerDirtyRectBound = lowerUpdatingRectBound = glm::ivec2(0, 0);
    }

    for (auto it = dirtyRects.begin(); it != dirtyRects.end(); ++it) {
        lowerUpdatingRectBound = glm::min(
            lowerUpdatingRectBound,
            glm::ivec2(it->x, it->y)
        );
        upperUpdatingRectBound = glm::max(
            upperUpdatingRectBound,
            glm::ivec2(it->x + it->width, it->y + it->height)
        );
    }
    const glm::ivec2 rectSize = upperUpdatingRectBound - lowerUpdatingRectBound;
    if (rectSize.x > 0 && rectSize.y > 0) {
        _textureIsDirty = true;
    } else {
        return;
    }

    // Copy the updated rectangle line by line.
    for (int y = lowerUpdatingRectBound.y; y < upperUpdatingRectBound.y; ++y) {
        int lineOffset = y * w + lowerUpdatingRectBound.x;
        int rectWidth = upperUpdatingRectBound.x - lowerUpdatingRectBound.x;
        std::copy(
            reinterpret_cast<const Pixel*>(buffer) + lineOffset,
            reinterpret_cast<const Pixel*>(buffer) + lineOffset + rectWidth,
            _browserBuffer.data() + lineOffset
        );
    }

    // Add the dirty rect bounds to the GPU texture dirty rect.
    _lowerDirtyRectBound = glm::min(lowerUpdatingRectBound, _lowerDirtyRectBound);
    _upperDirtyRectBound = glm::max(upperUpdatingRectBound, _upperDirtyRectBound);
    _needsRepaint = false;
}

void WebRenderHandler::updateTexture() {
    if (_needsRepaint) {
        return;
    }

    if (_textureSizeIsDirty) {
        glBindTexture(GL_TEXTURE_2D, _texture);
        glTexImage2D(
            GL_TEXTURE_2D,
            0,
            GL_RGBA,
            _browserBufferSize.x,
            _browserBufferSize.y,
            0,
            GL_BGRA_EXT,
            GL_UNSIGNED_BYTE,
            reinterpret_cast<char*>(_browserBuffer.data())
        );
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
        glBindTexture(GL_TEXTURE_2D, 0);
    } else if (_textureIsDirty) {
        glBindTexture(GL_TEXTURE_2D, _texture);
        glPixelStorei(GL_UNPACK_ROW_LENGTH, _browserBufferSize.x);

        glTexSubImage2D(
            GL_TEXTURE_2D,
            0,
            _lowerDirtyRectBound.x,
            _lowerDirtyRectBound.y,
            _upperDirtyRectBound.x - _lowerDirtyRectBound.x,
            _upperDirtyRectBound.y - _lowerDirtyRectBound.y,
            GL_BGRA_EXT,
            GL_UNSIGNED_BYTE,
            reinterpret_cast<char*>(
                _browserBuffer.data() +
                _lowerDirtyRectBound.y * _browserBufferSize.x + _lowerDirtyRectBound.x
            )
        );

        glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
        glBindTexture(GL_TEXTURE_2D, 0);
    }

    _upperDirtyRectBound = glm::ivec2(0, 0);
    _lowerDirtyRectBound = glm::ivec2(_browserBufferSize.x, _browserBufferSize.y);
    _textureSizeIsDirty = false;
    _textureIsDirty = false;
}

bool WebRenderHandler::hasContent(int x, int y) {
    if (_browserBuffer.empty()) {
        return false;
    }
    int index = x + (_browserBufferSize.x * y);
    index = glm::clamp(index, 0, static_cast<int>(_browserBuffer.size() - 1));
    return _browserBuffer[index].a;
}

bool WebRenderHandler::isTextureReady() const {
    return !_needsRepaint;
}

} // namespace openspace