C++ GLTexture::setFilter方法代码示例

//.........这里部分代码省略.........
                    if (hardwareClipping) {
                        glDisable(GL_SCISSOR_TEST);
                    }
                    cachedTexture->unbind();
                    m_timer.start(5000, this);
                    return;
                } else {
                    // offscreen texture not matching - delete
                    delete cachedTexture;
                    cachedTexture = 0;
                    w->setData(LanczosCacheRole, QVariant());
                }
            }

            WindowPaintData thumbData = data;
            thumbData.setXScale(1.0);
            thumbData.setYScale(1.0);
            thumbData.setXTranslation(-w->x() - left);
            thumbData.setYTranslation(-w->y() - top);
            thumbData.setBrightness(1.0);
            thumbData.setOpacity(1.0);
            thumbData.setSaturation(1.0);

            // Bind the offscreen FBO and draw the window on it unscaled
            updateOffscreenSurfaces();
            GLRenderTarget::pushRenderTarget(m_offscreenTarget);

            glClearColor(0.0, 0.0, 0.0, 0.0);
            glClear(GL_COLOR_BUFFER_BIT);
            w->sceneWindow()->performPaint(mask, infiniteRegion(), thumbData);

            // Create a scratch texture and copy the rendered window into it
            GLTexture tex(sw, sh);
            tex.setFilter(GL_LINEAR);
            tex.setWrapMode(GL_CLAMP_TO_EDGE);
            tex.bind();

            glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, m_offscreenTex->height() - sh, sw, sh);

            // Set up the shader for horizontal scaling
            float dx = sw / float(tw);
            int kernelSize;
            m_shader->createKernel(dx, &kernelSize);
            m_shader->createOffsets(kernelSize, sw, Qt::Horizontal);

            m_shader->bind();
            m_shader->setUniforms();

            // Draw the window back into the FBO, this time scaled horizontally
            glClear(GL_COLOR_BUFFER_BIT);
            QVector<float> verts;
            QVector<float> texCoords;
            verts.reserve(12);
            texCoords.reserve(12);

            texCoords << 1.0 << 0.0; verts << tw  << 0.0; // Top right
            texCoords << 0.0 << 0.0; verts << 0.0 << 0.0; // Top left
            texCoords << 0.0 << 1.0; verts << 0.0 << sh;  // Bottom left
            texCoords << 0.0 << 1.0; verts << 0.0 << sh;  // Bottom left
            texCoords << 1.0 << 1.0; verts << tw  << sh;  // Bottom right
            texCoords << 1.0 << 0.0; verts << tw  << 0.0; // Top right
            GLVertexBuffer *vbo = GLVertexBuffer::streamingBuffer();
            vbo->reset();
            vbo->setData(6, 2, verts.constData(), texCoords.constData());
            vbo->render(GL_TRIANGLES);

void BlurEffect::doCachedBlur(EffectWindow *w, const QRegion& region, const float opacity)
{
    const QRect screen = effects->virtualScreenGeometry();
    const QRegion blurredRegion = blurRegion(w).translated(w->pos()) & screen;
    const QRegion expanded = expand(blurredRegion) & screen;
    const QRect r = expanded.boundingRect();

    // The background texture we get is only partially valid.

    CacheEntry it = windows.find(w);
    if (it == windows.end()) {
        BlurWindowInfo bwi;
        bwi.blurredBackground = GLTexture(r.width(),r.height());
        bwi.damagedRegion = expanded;
        bwi.dropCache = false;
        bwi.windowPos = w->pos();
        it = windows.insert(w, bwi);
    } else if (it->blurredBackground.size() != r.size()) {
        it->blurredBackground = GLTexture(r.width(),r.height());
        it->dropCache = false;
        it->windowPos = w->pos();
    } else if (it->windowPos != w->pos()) {
        it->dropCache = false;
        it->windowPos = w->pos();
    }

    GLTexture targetTexture = it->blurredBackground;
    targetTexture.setFilter(GL_LINEAR);
    targetTexture.setWrapMode(GL_CLAMP_TO_EDGE);
    shader->bind();
    QMatrix4x4 textureMatrix;
    QMatrix4x4 modelViewProjectionMatrix;

    /**
     * Which part of the background texture can be updated ?
     *
     * Well this is a rather difficult question. We kind of rely on the fact, that
     * we need a bigger background region being painted before, more precisely if we want to
     * blur region A we need the background region expand(A). This business logic is basically
     * done in prePaintWindow:
     *          data.paint |= expand(damagedArea);
     *
     * Now "data.paint" gets clipped and becomes what we receive as the "region" variable
     * in this function. In theory there is now only one function that does this clipping
     * and this is paintSimpleScreen. The clipping has the effect that "damagedRegion"
     * is no longer a subset of "region" and we cannot fully validate the cache within one
     * rendering pass. If we would now update the "damageRegion & region" part of the cache
     * we would wrongly update the part of the cache that is next to the "region" border and
     * which lies within "damagedRegion", just because we cannot assume that the framebuffer
     * outside of "region" is valid. Therefore the maximal damaged region of the cache that can
     * be repainted is given by:
     *          validUpdate = damagedRegion - expand(damagedRegion - region);
     *
     * Now you may ask what is with the rest of "damagedRegion & region" that is not part
     * of "validUpdate" but also might end up on the screen. Well under the assumption
     * that only the occlusion culling can shrink "data.paint", we can control this by reducing
     * the opaque area of every window by a margin of the blurring radius (c.f. prePaintWindow).
     * This way we are sure that this area is overpainted by a higher opaque window.
     *
     * Apparently paintSimpleScreen is not the only function that can influence "region".
     * In fact every effect's paintWindow that is called before Blur::paintWindow
     * can do so (e.g. SlidingPopups). Hence we have to make the compromise that we update
     * "damagedRegion & region" of the cache but only mark "validUpdate" as valid.
     **/
    const QRegion damagedRegion = it->damagedRegion;
    const QRegion updateBackground = damagedRegion & region;
    const QRegion validUpdate = damagedRegion - expand(damagedRegion - region);

    const QRegion horizontal = validUpdate.isEmpty() ? QRegion() : (updateBackground & screen);
    const QRegion vertical   = blurredRegion & region;

    const int horizontalOffset = 0;
    const int horizontalCount = horizontal.rectCount() * 6;

    const int verticalOffset = horizontalCount;
    const int verticalCount = vertical.rectCount() * 6;

    GLVertexBuffer *vbo = GLVertexBuffer::streamingBuffer();
    uploadGeometry(vbo, horizontal, vertical);

    vbo->bindArrays();

    if (!validUpdate.isEmpty()) {
        const QRect updateRect = (expand(updateBackground) & expanded).boundingRect();
        // First we have to copy the background from the frontbuffer
        // into a scratch texture (in this case "tex").
        tex.bind();

        glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, updateRect.x(), displayHeight() - updateRect.y() - updateRect.height(),
                            updateRect.width(), updateRect.height());

        // Draw the texture on the offscreen framebuffer object, while blurring it horizontally
        target->attachTexture(targetTexture);
        GLRenderTarget::pushRenderTarget(target);

        shader->setDirection(Qt::Horizontal);
        shader->setPixelDistance(1.0 / tex.width());

        modelViewProjectionMatrix.ortho(0, r.width(), r.height(), 0 , 0, 65535);
        modelViewProjectionMatrix.translate(-r.x(), -r.y(), 0);
//.........这里部分代码省略.........