Add letter grid animation

5 files changed, 44 insertions, 23 deletions

diff --git a/3ner.shader b/3ner.shader
index 710d456..4627ba0 100755
--- a/3ner.shader
+++ b/3ner.shader
@@ -1049,18 +1049,26 @@ Shader "yum_food/3ner"
           _Letter_Grid_Data_Row_1("Cell data row 1", Vector) = (0, 0, 0, 0)
           _Letter_Grid_Data_Row_2("Cell data row 2", Vector) = (0, 0, 0, 0)
           _Letter_Grid_Data_Row_3("Cell data row 3", Vector) = (0, 0, 0, 0)
+          [IntRange] _Letter_Grid_UV_Channel("UV Channel", Range(0, 3)) = 0
           _Letter_Grid_UV_Scale_Offset("UV scale/offset", Vector) = (1, 1, 0, 0)
           _Letter_Grid_Padding("Padding", Float) = 0.02
           _Letter_Grid_Color("Color", Color) = (1, 1, 1, 1)
           _Letter_Grid_Metallic("Metallic", Range(0, 1)) = 0
           _Letter_Grid_Roughness("Roughness", Range(0 ,1)) = 0.5
           _Letter_Grid_Emission("Emission", Range(0 ,1)) = 0.0
-          _Letter_Grid_Mask("Mask", 2D) = "white" {}
           _Letter_Grid_Global_Offset("Global offset", Float) = 0
           _Letter_Grid_Screen_Px_Range("Screen px range (from msdfgen)", Float) = 10
           _Letter_Grid_Min_Screen_Px_Range("Minimum screen px range", Float) = 1
           _Letter_Grid_Blurriness("Blurriness", Float) = 0.5
           _Letter_Grid_Alpha_Threshold("Alpha threshold", Range(0, 1)) = 0.5
+
+          //ifex _Letter_Grid_Animate_Enabled==0
+          [HideInInspector] m_start_Letter_Grid_Animate("Animate", Float) = 0
+            [ThryToggle(_LETTER_GRID_ANIMATE)] _Letter_Grid_Animate_Enabled("Enable", Float) = 0
+            _Letter_Grid_Animate_Speed("Speed", Range(0, 1)) = 0.1
+          [HideInInspector] m_end_Letter_Grid_Animate("Animate", Float) = 0
+          //endex
+
         [HideInInspector] m_end_Letter_Grid("Letter grid", Float) = 0
         //endex
 
diff --git a/Scripts/gen_atlas b/Scripts/gen_atlas
index a3fac72..7400013 100755
--- a/Scripts/gen_atlas
+++ b/Scripts/gen_atlas
@@ -69,9 +69,9 @@ CHAR_RANGES = [
     (0x0370, 0x03ff), # greek and coptic
     (0x0400, 0x04ff), # cyrillic
     (0x0500, 0x052f), # cyrillic supplement
-    (0x0530, 0x058f), # armenian
-    (0x0590, 0x05ff), # hebrew
-    (0x0600, 0x06ff), # arabic
+    #(0x0530, 0x058f), # armenian
+    #(0x0590, 0x05ff), # hebrew
+    #(0x0600, 0x06ff), # arabic
 ]
 
 def calculate_grid_size(char_ranges):
diff --git a/features.cginc b/features.cginc
index 61b59e0..ab81cb2 100755
--- a/features.cginc
+++ b/features.cginc
@@ -228,6 +228,7 @@
 
 //ifex _Letter_Grid_Enabled==0
 #pragma shader_feature_local _LETTER_GRID
+#pragma shader_feature_local _LETTER_GRID_ANIMATE
 //endex
 
 #endif  // __FEATURES_INC
diff --git a/globals.cginc b/globals.cginc
index e567177..44a71c9 100755
--- a/globals.cginc
+++ b/globals.cginc
@@ -579,6 +579,7 @@ float4 _Letter_Grid_Data_Row_0;
 float4 _Letter_Grid_Data_Row_1;
 float4 _Letter_Grid_Data_Row_2;
 float4 _Letter_Grid_Data_Row_3;
+int _Letter_Grid_UV_Channel;
 float4 _Letter_Grid_UV_Scale_Offset;
 float _Letter_Grid_Padding;
 float4 _Letter_Grid_Color;
@@ -593,4 +594,8 @@ float _Letter_Grid_Blurriness;
 float _Letter_Grid_Alpha_Threshold;
 #endif  // _LETTER_GRID
 
+#if defined(_LETTER_GRID_ANIMATE)
+float _Letter_Grid_Animate_Speed;
+#endif  // _LETTER_GRID_ANIMATE
+
 #endif  // __GLOBALS_INC
diff --git a/letter_grid.cginc b/letter_grid.cginc
index 61c147b..50b4ee3 100644
--- a/letter_grid.cginc
+++ b/letter_grid.cginc
@@ -1,6 +1,7 @@
 #ifndef __LETTER_GRID_INC
 #define __LETTER_GRID_INC
 
+#include "audiolink.cginc"
 #include "disinfo.cginc"
 #include "features.cginc"
 #include "globals.cginc"
@@ -20,14 +21,15 @@ struct LetterGridOutput {
 LetterGridOutput LetterGrid(v2f i) {
     LetterGridOutput output;
 
-    int2 cell_pos;
     int2 font_res = int2(round(_Letter_Grid_Tex_Res_X), round(_Letter_Grid_Tex_Res_Y));
     int2 grid_res = int2(round(_Letter_Grid_Res_X), round(_Letter_Grid_Res_Y));
-    float2 cell_uv;  // uv within each letter cell
 
     float4 scoff = _Letter_Grid_UV_Scale_Offset;
-    float2 uv = ((i.uv01.xy - 0.5) - scoff.zw) * scoff.xy + 0.5;
+    float2 base_uv = get_uv_by_channel(i, _Letter_Grid_UV_Channel);
+    float2 uv = ((base_uv - 0.5) - scoff.zw) * scoff.xy + 0.5;
 
+    int2 cell_pos;
+    float2 cell_uv;  // uv within each letter cell
     bool in_box = getBoxLoc(uv, 0, 1, grid_res, _Letter_Grid_Padding, cell_pos, cell_uv);
 
     // Extract char from _Letter_Grid_Data_Row_0 et al using cell_pos.
@@ -43,32 +45,38 @@ LetterGridOutput LetterGrid(v2f i) {
         cell_pos.y - 2),
         cell_pos.y/2);
     c += _Letter_Grid_Global_Offset;
+#if defined(_LETTER_GRID_ANIMATE)
+    // Sweep cells left-to-right, then top-to-bottom. One full sweep takes
+    // _Letter_Grid_Animate_Speed seconds, so each slot updates once per sweep.
+    int slot_count = max(grid_res.x * grid_res.y, 1);
+    int slot_index = cell_pos.y * grid_res.x + cell_pos.x;
+    int sweep_step = (int)floor((_Time.y * _Letter_Grid_Animate_Speed) * slot_count);
+    int slot_change_count = (sweep_step + slot_count - slot_index) / slot_count;
+
+    int glyph_count = max(font_res.x * font_res.y, 1);
+    int base_char = (int)round(c);
+    uint rand_u = hash31_u32(uint3(
+        (uint)slot_index,
+        (uint)slot_change_count,
+        asuint(base_char)));
+    c = (float)(rand_u % glyph_count);
+#endif
 
     float3 msd = renderInBox(c, uv, cell_uv, _Letter_Grid_Texture, font_res).rgb;
     float sd = median(msd);
 
-    // Calculate screen pixel range
     float screen_px_range;
     {
         float2 tex_size = float2(_Letter_Grid_Texture_TexelSize.zw);
-        float2 real_cell_size = floor(tex_size / grid_res);  // size of cell in texels
-        float2 unit_range = _Letter_Grid_Screen_Px_Range / real_cell_size;
-        float2 screen_tex_size = 1 / fwidth(cell_uv);
+        float2 glyph_tex_size = tex_size / float2(font_res);
+        float2 unit_range = _Letter_Grid_Screen_Px_Range / glyph_tex_size;
+        float2 screen_tex_size = 1.0 / max(fwidth(cell_uv), float2(1e-4, 1e-4));
         screen_px_range = max(0.5 * dot(unit_range, screen_tex_size), _Letter_Grid_Min_Screen_Px_Range);
     }
 
     float screen_px_distance = screen_px_range * (sd - _Letter_Grid_Alpha_Threshold);
-    float smooth_range = (length(grid_res) / sqrt(screen_px_range)) * _Letter_Grid_Blurriness;
-    float op = smoothstep(-smooth_range, smooth_range, screen_px_distance);
-
-    // Sample mask if enabled
-    #if defined(_LETTER_GRID_MASK)
-    float mask = _Letter_Grid_Mask.Sample(linear_repeat_s, i.uv01.xy).r;
-    #else
-    float mask = 1.0;
-    #endif
-
-    op *= mask;
+    float edge_softness = max(exp2((_Letter_Grid_Blurriness - 0.5) * 2.0), 1e-4);
+    float op = saturate(screen_px_distance / edge_softness + 0.5);
 
     // Apply blending to output
     output.albedo = float4(_Letter_Grid_Color.rgb, op * in_box);
@@ -82,4 +90,3 @@ LetterGridOutput LetterGrid(v2f i) {
 #endif  // _LETTER_GRID
 
 #endif  // __LETTER_GRID_INC
-