virtual GLTexture createTexture(const QString& fileName) const
{
if (m_texMan != NULL)
{
return m_texMan->createTexture(fileName);
}
else
{
return GLTexture();
}
}
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);
shader->setModelViewProjectionMatrix(modelViewProjectionMatrix);
// Set up the texture matrix to transform from screen coordinates
// to texture coordinates.
textureMatrix.scale(1.0 / tex.width(), -1.0 / tex.height(), 1);
textureMatrix.translate(-updateRect.x(), -updateRect.height() - updateRect.y(), 0);
shader->setTextureMatrix(textureMatrix);
vbo->draw(GL_TRIANGLES, horizontalOffset, horizontalCount);
GLRenderTarget::popRenderTarget();
tex.unbind();
// mark the updated region as valid
it->damagedRegion -= validUpdate;
}
// Now draw the horizontally blurred area back to the backbuffer, while
// blurring it vertically and clipping it to the window shape.
targetTexture.bind();
shader->setDirection(Qt::Vertical);
shader->setPixelDistance(1.0 / targetTexture.height());
// Modulate the blurred texture with the window opacity if the window isn't opaque
if (opacity < 1.0) {
glEnable(GL_BLEND);
glBlendColor(0, 0, 0, opacity);
glBlendFunc(GL_CONSTANT_ALPHA, GL_ONE_MINUS_CONSTANT_ALPHA);
}
modelViewProjectionMatrix.setToIdentity();
const QSize screenSize = effects->virtualScreenSize();
modelViewProjectionMatrix.ortho(0, screenSize.width(), screenSize.height(), 0, 0, 65535);
shader->setModelViewProjectionMatrix(modelViewProjectionMatrix);
// Set the up the texture matrix to transform from screen coordinates
// to texture coordinates.
textureMatrix.setToIdentity();
textureMatrix.scale(1.0 / targetTexture.width(), -1.0 / targetTexture.height(), 1);
textureMatrix.translate(-r.x(), -targetTexture.height() - r.y(), 0);
shader->setTextureMatrix(textureMatrix);
vbo->draw(GL_TRIANGLES, verticalOffset, verticalCount);
vbo->unbindArrays();
if (opacity < 1.0) {
glDisable(GL_BLEND);
}
targetTexture.unbind();
shader->unbind();
}
