From 1e4fb80d46da634f04d84e3f1065aaabc6909468 Mon Sep 17 00:00:00 2001
From: Aaron Suen <warr1024@gmail.com>
Date: Sat, 7 Mar 2015 19:52:59 -0500
Subject: [PATCH] Configurable automatic texture scaling and filtering at load
time.
Signed off by: Zeno, kwolekr
---
minetest.conf.example | 13 +++++++
src/client/tile.cpp | 83 +++++++++++++++++++++++++++++++++++++++++
src/defaultsettings.cpp | 2 +
3 files changed, 98 insertions(+)
diff --git a/minetest.conf.example b/minetest.conf.example
index 5e8637897..2c6f5e861 100644
--- a/minetest.conf.example
+++ b/minetest.conf.example
@@ -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.
diff --git a/src/client/tile.cpp b/src/client/tile.cpp
index 541247fa8..078e62741 100644
--- a/src/client/tile.cpp
+++ b/src/client/tile.cpp
@@ -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;
diff --git a/src/defaultsettings.cpp b/src/defaultsettings.cpp
index f49fbb008..ff2d148aa 100644
--- a/src/defaultsettings.cpp
+++ b/src/defaultsettings.cpp
@@ -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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