DRTVWR-592: (WIP) Triplanar mapping

3 files changed, 177 insertions, 78 deletions

diff --git a/indra/newview/app_settings/shaders/class1/deferred/pbrterrainF.glsl b/indra/newview/app_settings/shaders/class1/deferred/pbrterrainF.glsl
index e6261ca85e..5bf20a3020 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/pbrterrainF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/pbrterrainF.glsl
@@ -25,6 +25,15 @@
 
 #define TERRAIN_PBR_DETAIL_EMISSIVE 0
 
+#define TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT 3 // TODO: Move definition to config
+
+// TODO: Should be able to define this in another file and have it included in this one...
+#if TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT == 3
+#define TerrainCoord vec4[2]
+#elif TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT == 1
+#define TerrainCoord vec2
+#endif
+
 out vec4 frag_data[4];
 
 uniform sampler2D alpha_ramp;
@@ -60,6 +69,7 @@ uniform vec3[4] emissiveColors;
 #endif
 uniform vec4 minimum_alphas; // PBR alphaMode: MASK, See: mAlphaCutoff, setAlphaCutoff()
 
+in vec4[2] vary_coords;
 in vec3 vary_normal;
 in vec3 vary_tangent;
 flat in float vary_sign;
@@ -67,88 +77,22 @@ in vec4 vary_texcoord0;
 in vec4 vary_texcoord1;
 
 vec2 encode_normal(vec3 n);
-vec3 linear_to_srgb(vec3 c);
-vec3 srgb_to_linear(vec3 c);
-
-// *TODO: This mixing function feels like it can be optimized. The terrain code's use of texcoord1 is dubious. It feels like the same thing can be accomplished with less memory bandwidth by calculating the offsets on-the-fly
-float terrain_mix(vec4 samples, float alpha1, float alpha2, float alphaFinal)
-{
-    return mix( mix(samples.w, samples.z, alpha2), mix(samples.y, samples.x, alpha1), alphaFinal );
-}
-
-vec3 terrain_mix(vec3[4] samples, float alpha1, float alpha2, float alphaFinal)
-{
-    return mix( mix(samples[3], samples[2], alpha2), mix(samples[1], samples[0], alpha1), alphaFinal );
-}
-
-vec4 terrain_mix(vec4[4] samples, float alpha1, float alpha2, float alphaFinal)
-{
-    return mix( mix(samples[3], samples[2], alpha2), mix(samples[1], samples[0], alpha1), alphaFinal );
-}
 
-vec3 sample_and_mix_color3(float alpha1, float alpha2, float alphaFinal, vec2 texcoord, vec3[4] factors, sampler2D tex0, sampler2D tex1, sampler2D tex2, sampler2D tex3)
-{
-    vec3[4] samples;
-    samples[0] = texture(tex0, texcoord).xyz;
-    samples[1] = texture(tex1, texcoord).xyz;
-    samples[2] = texture(tex2, texcoord).xyz;
-    samples[3] = texture(tex3, texcoord).xyz;
-    samples[0] = srgb_to_linear(samples[0]);
-    samples[1] = srgb_to_linear(samples[1]);
-    samples[2] = srgb_to_linear(samples[2]);
-    samples[3] = srgb_to_linear(samples[3]);
-    samples[0] *= factors[0];
-    samples[1] *= factors[1];
-    samples[2] *= factors[2];
-    samples[3] *= factors[3];
-    return terrain_mix(samples, alpha1, alpha2, alphaFinal);
-}
-
-vec4 sample_and_mix_color4(float alpha1, float alpha2, float alphaFinal, vec2 texcoord, vec4[4] factors, sampler2D tex0, sampler2D tex1, sampler2D tex2, sampler2D tex3)
-{
-    vec4[4] samples;
-    samples[0] = texture(tex0, texcoord);
-    samples[1] = texture(tex1, texcoord);
-    samples[2] = texture(tex2, texcoord);
-    samples[3] = texture(tex3, texcoord);
-    samples[0].xyz = srgb_to_linear(samples[0].xyz);
-    samples[1].xyz = srgb_to_linear(samples[1].xyz);
-    samples[2].xyz = srgb_to_linear(samples[2].xyz);
-    samples[3].xyz = srgb_to_linear(samples[3].xyz);
-    samples[0] *= factors[0];
-    samples[1] *= factors[1];
-    samples[2] *= factors[2];
-    samples[3] *= factors[3];
-    return terrain_mix(samples, alpha1, alpha2, alphaFinal);
-}
+float terrain_mix(vec4 samples, float alpha1, float alpha2, float alphaFinal);
+vec3 sample_and_mix_color3(float alpha1, float alpha2, float alphaFinal, TerrainCoord texcoord, vec3[4] factors, sampler2D tex0, sampler2D tex1, sampler2D tex2, sampler2D tex3);
+vec4 sample_and_mix_color4(float alpha1, float alpha2, float alphaFinal, TerrainCoord texcoord, vec4[4] factors, sampler2D tex0, sampler2D tex1, sampler2D tex2, sampler2D tex3);
+vec3 sample_and_mix_vector3(float alpha1, float alpha2, float alphaFinal, TerrainCoord texcoord, vec3[4] factors, sampler2D tex0, sampler2D tex1, sampler2D tex2, sampler2D tex3);
+vec3 sample_and_mix_vector3_no_scale(float alpha1, float alpha2, float alphaFinal, TerrainCoord texcoord, sampler2D tex0, sampler2D tex1, sampler2D tex2, sampler2D tex3);
 
-vec3 sample_and_mix_vector3(float alpha1, float alpha2, float alphaFinal, vec2 texcoord, vec3[4] factors, sampler2D tex0, sampler2D tex1, sampler2D tex2, sampler2D tex3)
+void main()
 {
-    vec3[4] samples;
-    samples[0] = texture(tex0, texcoord).xyz;
-    samples[1] = texture(tex1, texcoord).xyz;
-    samples[2] = texture(tex2, texcoord).xyz;
-    samples[3] = texture(tex3, texcoord).xyz;
-    samples[0] *= factors[0];
-    samples[1] *= factors[1];
-    samples[2] *= factors[2];
-    samples[3] *= factors[3];
-    return terrain_mix(samples, alpha1, alpha2, alphaFinal);
-}
 
-vec3 sample_and_mix_vector3_no_scale(float alpha1, float alpha2, float alphaFinal, vec2 texcoord, sampler2D tex0, sampler2D tex1, sampler2D tex2, sampler2D tex3)
-{
-    vec3[4] samples;
-    samples[0] = texture(tex0, texcoord).xyz;
-    samples[1] = texture(tex1, texcoord).xyz;
-    samples[2] = texture(tex2, texcoord).xyz;
-    samples[3] = texture(tex3, texcoord).xyz;
-    return terrain_mix(samples, alpha1, alpha2, alphaFinal);
-}
+#if TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT == 3
+    TerrainCoord terrain_texcoord = vary_coords;
+#elif TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT == 1
+    TerrainCoord terrain_texcoord = vary_texcoord0.xy;
+#endif
 
-void main()
-{
-    vec2 terrain_texcoord = vary_texcoord0.xy;
     float alpha1 = texture(alpha_ramp, vary_texcoord0.zw).a;
     float alpha2 = texture(alpha_ramp,vary_texcoord1.xy).a;
     float alphaFinal = texture(alpha_ramp, vary_texcoord1.zw).a;
diff --git a/indra/newview/app_settings/shaders/class1/deferred/pbrterrainUtilF.glsl b/indra/newview/app_settings/shaders/class1/deferred/pbrterrainUtilF.glsl
new file mode 100644
index 0000000000..4f337b5ce1
--- /dev/null
+++ b/indra/newview/app_settings/shaders/class1/deferred/pbrterrainUtilF.glsl
@@ -0,0 +1,148 @@
+/** 
+ * @file class1\deferred\pbrterrainUtilF.glsl
+ *
+ * $LicenseInfo:firstyear=2023&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2023, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+/**
+ * Triplanar mapping implementation adapted from Inigo Quilez' example shader,
+ * MIT license.
+ * https://www.shadertoy.com/view/MtsGWH
+ * Copyright © 2015 Inigo Quilez
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions: The above copyright
+ * notice and this permission notice shall be included in all copies or
+ * substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS",
+ * WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+ * TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
+ * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+in vec3 vary_vertex_normal;
+
+vec3 srgb_to_linear(vec3 c);
+
+float terrain_mix(vec4 samples, float alpha1, float alpha2, float alphaFinal)
+{
+    return mix( mix(samples.w, samples.z, alpha2), mix(samples.y, samples.x, alpha1), alphaFinal );
+}
+
+vec3 terrain_mix(vec3[4] samples, float alpha1, float alpha2, float alphaFinal)
+{
+    return mix( mix(samples[3], samples[2], alpha2), mix(samples[1], samples[0], alpha1), alphaFinal );
+}
+
+vec4 terrain_mix(vec4[4] samples, float alpha1, float alpha2, float alphaFinal)
+{
+    return mix( mix(samples[3], samples[2], alpha2), mix(samples[1], samples[0], alpha1), alphaFinal );
+}
+
+#define TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT 3 // TODO: Move definition to config
+
+#if TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT == 3
+// Pre-transformed texture coordinates for each axial uv slice (Packing: xy, yz, zx, unused)
+#define TerrainCoord vec4[2]
+// Triplanar mapping
+vec4 terrain_texture(sampler2D tex, TerrainCoord terrain_coord)
+{
+    vec4 x = texture(tex, terrain_coord[0].zw);
+    vec4 y = texture(tex, terrain_coord[1].xy);
+    vec4 z = texture(tex, terrain_coord[0].xy);
+    float sharpness = 8.0;
+    vec3 weight = pow(abs(vary_vertex_normal), vec3(sharpness));
+    return ((x * weight.x) + (y * weight.y) + (z * weight.z)) / (weight.x + weight.y + weight.z);
+}
+#elif TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT == 1
+#define TerrainCoord vec2
+vec4 terrain_texture(sampler2D tex, TerrainCoord terrain_coord)
+{
+    return texture(tex, terrain_coord);
+}
+#endif
+
+vec3 sample_and_mix_color3(float alpha1, float alpha2, float alphaFinal, TerrainCoord texcoord, vec3[4] factors, sampler2D tex0, sampler2D tex1, sampler2D tex2, sampler2D tex3)
+{
+    vec3[4] samples;
+    samples[0] = terrain_texture(tex0, texcoord).xyz;
+    samples[1] = terrain_texture(tex1, texcoord).xyz;
+    samples[2] = terrain_texture(tex2, texcoord).xyz;
+    samples[3] = terrain_texture(tex3, texcoord).xyz;
+    samples[0] = srgb_to_linear(samples[0]);
+    samples[1] = srgb_to_linear(samples[1]);
+    samples[2] = srgb_to_linear(samples[2]);
+    samples[3] = srgb_to_linear(samples[3]);
+    samples[0] *= factors[0];
+    samples[1] *= factors[1];
+    samples[2] *= factors[2];
+    samples[3] *= factors[3];
+    return terrain_mix(samples, alpha1, alpha2, alphaFinal);
+}
+
+vec4 sample_and_mix_color4(float alpha1, float alpha2, float alphaFinal, TerrainCoord texcoord, vec4[4] factors, sampler2D tex0, sampler2D tex1, sampler2D tex2, sampler2D tex3)
+{
+    vec4[4] samples;
+    samples[0] = terrain_texture(tex0, texcoord);
+    samples[1] = terrain_texture(tex1, texcoord);
+    samples[2] = terrain_texture(tex2, texcoord);
+    samples[3] = terrain_texture(tex3, texcoord);
+    samples[0].xyz = srgb_to_linear(samples[0].xyz);
+    samples[1].xyz = srgb_to_linear(samples[1].xyz);
+    samples[2].xyz = srgb_to_linear(samples[2].xyz);
+    samples[3].xyz = srgb_to_linear(samples[3].xyz);
+    samples[0] *= factors[0];
+    samples[1] *= factors[1];
+    samples[2] *= factors[2];
+    samples[3] *= factors[3];
+    return terrain_mix(samples, alpha1, alpha2, alphaFinal);
+}
+
+vec3 sample_and_mix_vector3(float alpha1, float alpha2, float alphaFinal, TerrainCoord texcoord, vec3[4] factors, sampler2D tex0, sampler2D tex1, sampler2D tex2, sampler2D tex3)
+{
+    vec3[4] samples;
+    samples[0] = terrain_texture(tex0, texcoord).xyz;
+    samples[1] = terrain_texture(tex1, texcoord).xyz;
+    samples[2] = terrain_texture(tex2, texcoord).xyz;
+    samples[3] = terrain_texture(tex3, texcoord).xyz;
+    samples[0] *= factors[0];
+    samples[1] *= factors[1];
+    samples[2] *= factors[2];
+    samples[3] *= factors[3];
+    return terrain_mix(samples, alpha1, alpha2, alphaFinal);
+}
+
+vec3 sample_and_mix_vector3_no_scale(float alpha1, float alpha2, float alphaFinal, TerrainCoord texcoord, sampler2D tex0, sampler2D tex1, sampler2D tex2, sampler2D tex3)
+{
+    vec3[4] samples;
+    samples[0] = terrain_texture(tex0, texcoord).xyz;
+    samples[1] = terrain_texture(tex1, texcoord).xyz;
+    samples[2] = terrain_texture(tex2, texcoord).xyz;
+    samples[3] = terrain_texture(tex3, texcoord).xyz;
+    return terrain_mix(samples, alpha1, alpha2, alphaFinal);
+}
diff --git a/indra/newview/app_settings/shaders/class1/deferred/pbrterrainV.glsl b/indra/newview/app_settings/shaders/class1/deferred/pbrterrainV.glsl
index 1653cc1a90..991783d242 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/pbrterrainV.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/pbrterrainV.glsl
@@ -34,6 +34,8 @@ in vec4 diffuse_color;
 in vec2 texcoord0;
 in vec2 texcoord1;
 
+out vec4[2] vary_coords;
+out vec3 vary_vertex_normal; // Used by pbrterrainUtilF.glsl
 out vec3 vary_normal;
 out vec3 vary_tangent;
 flat out float vary_sign;
@@ -63,6 +65,8 @@ void main()
 	gl_Position = modelview_projection_matrix * vec4(position.xyz, 1.0); 
 
 	vec3 n = normal_matrix * normal;
+    // *TODO: Looks like terrain normals are per-vertex when they should be per-triangle instead, causing incorrect values on triangles touching steep edges of terrain
+    vary_vertex_normal = normal;
 	vec3 t = normal_matrix * tangent.xyz;
 
     vary_tangent = normalize(t);
@@ -73,7 +77,10 @@ void main()
     // *NOTE: KHR texture transform is ignored for now
     vary_texcoord0.xy = texgen_object_pbr(vec4(texcoord0, 0, 1), texture_matrix0, object_plane_s, object_plane_t).xy;
     
-    vec4 tc = vec4(texcoord1,0,1);
+    vec4 tc = vec4(texcoord1,0,1); // TODO: This is redundant. Better to just use position and ignore texcoord? (We still need to decide how to handle alpha ramp, though...)
+    vary_coords[0].xy = texgen_object_pbr(vec4(position.xy, 0, 1), texture_matrix0, object_plane_s, object_plane_t).xy;
+    vary_coords[0].zw = texgen_object_pbr(vec4(position.yz, 0, 1), texture_matrix0, object_plane_s, object_plane_t).xy;
+    vary_coords[1].xy = texgen_object_pbr(vec4(position.zx, 0, 1), texture_matrix0, object_plane_s, object_plane_t).xy;
     
     vary_texcoord0.zw = tc.xy;
     vary_texcoord1.xy = tc.xy-vec2(2.0, 0.0);