Bug#880943: pink-pony-data: GL shader error when using fancy water

[Steve Cotton]

Package: pink-pony-data
Version: 1.4.1-2
Severity: minor
Tags: patch

A trivial bug which I'm logging because it's something that
caused me to spend time checking that removing the glee-dev
dependency hadn't broken it.

In the settings, change "Simple water" to "Fancy water", and this
error appears:

/usr/share/games/pink-pony/GLSL/water.frag: Compilation failed.
0:29(51): error: no matching function for call to `pow(float, int)'; candidates are:
0:29(51): error:    float pow(float, float)
0:29(51): error:    vec2 pow(vec2, vec2)
0:29(51): error:    vec3 pow(vec3, vec3)
0:29(51): error:    vec4 pow(vec4, vec4)
0:29(47): error: operands to arithmetic operators must be numeric

-- System Information:
Debian Release: buster/sid
  APT prefers unstable-debug
  APT policy: (500, 'unstable-debug'), (500, 'unstable'), (500, 'testing')
Architecture: amd64 (x86_64)
Foreign Architectures: i386, arm64

Kernel: Linux 4.13.0-1-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash
Init: systemd (via /run/systemd/system)

Versions of packages pink-pony depends on:
ii  libc6                   2.24-17
ii  libdevil1c2             1.7.8-10+b2
ii  libftgl2                2.1.3~rc5-4+nmu1.1
ii  libgcc1                 1:7.2.0-12
ii  libgl1                  0.2.999+git20170802-5
ii  libgl1-mesa-glx         17.2.4-1
ii  libglfw3                3.2.1-1
ii  libglu1-mesa [libglu1]  9.0.0-2.1
ii  libilmbase12            2.2.0-12
ii  libprotobuf10           3.0.0-9.1
ii  libsdl-mixer1.2         1.2.12-14
ii  libsdl1.2debian         1.2.15+dfsg2-0.1
ii  libsigc++-2.0-0v5       2.10.0-1
ii  libstdc++6              7.2.0-12
ii  libtinyxml2.6.2v5       2.6.2-4
ii  pink-pony-data          1.4.1-2

pink-pony recommends no packages.

Versions of packages pink-pony suggests:
pn  pink-pony-dbg  <none>

-- no debconf information
-------------- next part --------------
Fix a bug in the fancy water shader, pow() expects two floats.

Fancy water can be enabled in the settings, by default the game
uses "simple water" instead.
Index: pink-pony/resources/GLSL/water.frag
===================================================================
--- pink-pony.orig/resources/GLSL/water.frag
+++ pink-pony/resources/GLSL/water.frag
@@ -26,7 +26,7 @@ float dispf(vec2 p)
 
 vec3 displacement(vec3 wp, float dist)
 {
-    return wp + normal * (dispf(wp.xz) * min(1.0,2.0/pow(dist,1)) * 0.5 + 0.5) * 4.0;
+    return wp + normal * (dispf(wp.xz) * min(1.0,2.0/pow(dist,1.0)) * 0.5 + 0.5) * 4.0;
 }
 
 void main (void)