yukijoou/kwin
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Add scaling support into BlurEffect::doBlur

Browse source 
Summary:
This patch caputres from the framebuffer using the framebuffer's
geometry, factoring in scale. We then keep the current normal DPI
framebuffer causing it to downsample there.

This is good because:
- it keeps the code very simple
- it's a performance optimisation. Blurring on 4k is naturally more
expensive than at regular DPI. Downsampling keeps it the same - and you
can't see a difference given it's high DPI and you're going to blur it
anwyay.
- it keeps kernel sizes somewhat resolution independent so it will look
just as blurry across multiple screens.

::doCachedBlur still needs doing.

Test Plan:
Ran an app
Ran the kwindowsystem blur test
Observed the right part of the window being blurred

Reviewers: #plasma

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D4963
This commit is contained in:
David Edmundson 2017-03-06 14:34:36 +00:00
parent 9cb666f469
commit 44a6050e83
1 changed files with 9 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

14
effects/blur/blur.cpp
View file

@ -522,16 +522,20 @@ void BlurEffect::doBlur(const QRegion& shape, const QRect& screen, const float o
uploadGeometry(vbo, expanded, shape);
vbo->bindArrays();
const qreal scale = GLRenderTarget::virtualScreenScale();
// Create a scratch texture and copy the area in the back buffer that we're
// going to blur into it
GLTexture scratch(GL_RGBA8, r.width(), r.height());
// for HIGH DPI scratch is captured in native resolution, it is then implicitly downsampled
// when rendering into tex
GLTexture scratch(GL_RGBA8, r.width() * scale, r.height() * scale);
scratch.setFilter(GL_LINEAR);
scratch.setWrapMode(GL_CLAMP_TO_EDGE);
scratch.bind();
const QRect sg = GLRenderTarget::virtualScreenGeometry();
glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, r.x() - sg.x(), sg.height() - sg.y() - r.y() - r.height(),
r.width(), r.height());
glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, (r.x() - sg.x()) * scale, (sg.height() - sg.y() - r.y() - r.height()) * scale,
scratch.width(), scratch.height());
// Draw the texture on the offscreen framebuffer object, while blurring it horizontally
target->attachTexture(tex);
@ -548,8 +552,8 @@ void BlurEffect::doBlur(const QRegion& shape, const QRect& screen, const float o
// Set up the texture matrix to transform from screen coordinates
// to texture coordinates.
QMatrix4x4 textureMatrix;
textureMatrix.scale(1.0 / scratch.width(), -1.0 / scratch.height(), 1);
textureMatrix.translate(-r.x(), -scratch.height() - r.y(), 0);
textureMatrix.scale(1.0 / r.width(), -1.0 / r.height(), 1);
textureMatrix.translate(-r.x(), (-r.height() - r.y()), 0);
shader->setTextureMatrix(textureMatrix);
vbo->draw(GL_TRIANGLES, 0, expanded.rectCount() * 6);