SuperTuxKart 1.5 upstream source (from official release tarball)

data/shaders/simple_particle.frag

@@ -0,0 +1,28 @@
+uniform sampler2D tex;
+uniform sampler2D dtex;
+uniform float billboard;
+
+in vec2 tc;
+in vec4 pc;
+out vec4 FragColor;
+
+#stk_include "utils/getPosFromUVDepth.frag"
+
+void main(void)
+{
+    vec4 color = texture(tex, tc) * pc;
+#if defined(Advanced_Lighting_Enabled)
+    vec2 xy = gl_FragCoord.xy / u_screen;
+    float FragZ = gl_FragCoord.z;
+    vec4 FragmentPos = getPosFromUVDepth(vec3(xy, FragZ), u_inverse_projection_matrix);
+    float EnvZ = texture(dtex, xy).x;
+    vec4 EnvPos = getPosFromUVDepth(vec3(xy, EnvZ), u_inverse_projection_matrix);
+    float alpha = clamp((EnvPos.z - FragmentPos.z) * 0.3, 0., 1.);
+    // TODO remove this later if possible when implementing GE
+    alpha = mix(alpha, texture(tex, tc).a, billboard);
+#else
+    float alpha = 1.0;
+#endif
+    color = vec4(color.rgb * color.a * alpha, color.a * alpha);
+    FragColor = color;
+}