GL 3.2 has texelFetch() and layout(pixel_center_integer), which means
that we integer coordinates with no precision loss when addressing
individual pixels in the source texture. In the versions before we have
to craft floating-point coordinates for texture() to grab the value of
wanted pixel with no jumping around or interpolation.
This change improves the behavior *a bit*, but not fully. I'm postponing
this to the point when I have an unit test that compares the output with
ground truth.
For some reason this was causing the inner for cycle to loop
indefinitely on AMD cards. Not a problem or NVidia drivers, Intel
Windows drivers or Mesa. Thanks a lot to @LB-- for the investigation.
Everything what was in src/ is now in src/Corrade, everything from
src/Plugins is now in src/MagnumPlugins, everything from external/ is in
src/MagnumExternal. Added new CMakeLists.txt file and updated the other
ones for the moves, no other change was made. If MAGNUM_BUILD_DEPRECATED
is set, everything compiles and installs like previously except for the
plugins, which are now in MagnumPlugins and not in Magnum/Plugins.
* Older GLSL doesn't have texelFetch() and related things, working
around it by using classical texture() and normalized floating-point
coordinates. But that needs to have Texture::imageSize() passed,
which is not available in OpenGL ES, thus the user must specify it
explicitly there. On desktop OpenGL that parameter is ignored.
* Older GLSL doesn't have gl_VertexID, thus vertex buffer must be
created and vertex data passed expliticly.
* GLSL ES 2.0 doesn't have one-component texture format and
TextureFormat::Luminance probably isn't renderable anywhere, thus
TextureFormat::RGB should be used, although it is inefficient.
* Checking for framebuffer completeness, if not complete, nothing is
done.
* Re-eabled building of TextureTools library in all ES PKGBUILDs.
Vladimír Vondruš