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Configurable automatic texture scaling and filtering at load time.

Signed off by: Zeno, kwolekr
  • Loading branch information
Warr1024 authored and kwolekr committed Mar 21, 2015
1 parent 26153ba commit 1e4fb80d46da634f04d84e3f1065aaabc6909468
Showing with 98 additions and 0 deletions.
  1. +13 −0 minetest.conf.example
  2. +83 −0 src/client/tile.cpp
  3. +2 −0 src/defaultsettings.cpp
@@ -193,6 +193,19 @@
#anisotropic_filter = false
#bilinear_filter = false
#trilinear_filter = false
# Filtered textures can blend RGB values with fully-transparent neighbors,
# which PNG optimizers usually discard, sometimes resulting in a dark or
# light edge to transparent textures. Apply this filter to clean that up
# at texture load time.
#texture_clean_transparent = true
# When using bilinear/trilinear/anisotropic filters, low-resolution textures
# can be blurred, so automatically upscale them with nearest-neighbor
# interpolation to preserve crisp pixels. This sets the minimum texture size
# for the upscaled textures; higher values look sharper, but require more
# memory. Powers of 2 are recommended. Setting this higher than 1 may not
# have a visible effect unless bilinear/trilinear/anisotropic filtering is
# enabled.
#texture_min_size = 16
# Set to true to pre-generate all item visuals
#preload_item_visuals = false
# Set to true to enable shaders. Disable them if video_driver = direct3d9/8.
@@ -223,6 +223,89 @@ class SourceImageCache
}
}

/* Apply the "clean transparent" filter to textures, removing borders on transparent textures.
* PNG optimizers discard RGB values of fully-transparent pixels, but filters may expose the
* replacement colors at borders by blending to them; this filter compensates for that by
* filling in those RGB values from nearby pixels.
*/
if (g_settings->getBool("texture_clean_transparent")) {
const core::dimension2d<u32> dim = toadd->getDimension();

// Walk each pixel looking for ones that will show as transparent.
for (u32 ctrx = 0; ctrx < dim.Width; ctrx++)
for (u32 ctry = 0; ctry < dim.Height; ctry++) {
irr::video::SColor c = toadd->getPixel(ctrx, ctry);
if (c.getAlpha() > 127)
continue;

// Sample size and total weighted r, g, b values.
u32 ss = 0, sr = 0, sg = 0, sb = 0;

// Walk each neighbor pixel (clipped to image bounds).
for (u32 sx = (ctrx < 1) ? 0 : (ctrx - 1);
sx <= (ctrx + 1) && sx < dim.Width; sx++)
for (u32 sy = (ctry < 1) ? 0 : (ctry - 1);
sy <= (ctry + 1) && sy < dim.Height; sy++) {

// Ignore the center pixel (its RGB is already
// presumed meaningless).
if ((sx == ctrx) && (sy == ctry))
continue;

// Ignore other nearby pixels that would be
// transparent upon display.
irr::video::SColor d = toadd->getPixel(sx, sy);
if(d.getAlpha() < 128)
continue;

// Add one weighted sample.
ss++;
sr += d.getRed();
sg += d.getGreen();
sb += d.getBlue();
}

// If we found any neighbor RGB data, set pixel to average
// weighted by alpha.
if (ss > 0) {
c.setRed(sr / ss);
c.setGreen(sg / ss);
c.setBlue(sb / ss);
toadd->setPixel(ctrx, ctry, c);
}
}
}

/* Upscale textures to user's requested minimum size. This is a trick to make
* filters look as good on low-res textures as on high-res ones, by making
* low-res textures BECOME high-res ones. This is helpful for worlds that
* mix high- and low-res textures, or for mods with least-common-denominator
* textures that don't have the resources to offer high-res alternatives.
*/
s32 scaleto = g_settings->getS32("texture_min_size");
if (scaleto > 0) {

/* Calculate scaling needed to make the shortest texture dimension
* equal to the target minimum. If e.g. this is a vertical frames
* animation, the short dimension will be the real size.
*/
const core::dimension2d<u32> dim = toadd->getDimension();
u32 xscale = scaleto / dim.Width;
u32 yscale = scaleto / dim.Height;
u32 scale = (xscale > yscale) ? xscale : yscale;

// Never downscale; only scale up by 2x or more.
if (scale > 1) {
u32 w = scale * dim.Width;
u32 h = scale * dim.Height;
const core::dimension2d<u32> newdim = core::dimension2d<u32>(w, h);
video::IImage *newimg = driver->createImage(
toadd->getColorFormat(), newdim);
toadd->copyToScaling(newimg);
toadd = newimg;
}
}

if (need_to_grab)
toadd->grab();
m_images[name] = toadd;
@@ -149,6 +149,8 @@ void set_default_settings(Settings *settings)
settings->setDefault("anisotropic_filter", "false");
settings->setDefault("bilinear_filter", "false");
settings->setDefault("trilinear_filter", "false");
settings->setDefault("texture_clean_transparent", "true");
settings->setDefault("texture_min_size", "16");
settings->setDefault("preload_item_visuals", "false");
settings->setDefault("enable_bumpmapping", "false");
settings->setDefault("enable_parallax_occlusion", "false");

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