Pass animation easing curve value to shaders in uniform

kitty/shaders.c

@@ -2334,6 +2334,7 @@ run_custom_end_shader(OSWindow *os_window, float sx, float sy, monotonic_t now)
 
     GLint group_loc = program_uniform_location(CUSTOM_END_PROGRAM, "group");
     GLint viewport_loc = program_uniform_location(CUSTOM_END_PROGRAM, "viewport");
+    GLint anim_progress_loc = program_uniform_location(CUSTOM_END_PROGRAM, "animation_progress");
     const unsigned num_groups = (unsigned)custom_shaders.end.num_groups;
     const unsigned textures_mask = custom_shaders.end.textures;
     const int vw = os_window->viewport_width, vh = os_window->viewport_height;
@@ -2433,8 +2434,17 @@ run_custom_end_shader(OSWindow *os_window, float sx, float sy, monotonic_t now)
             vp_h = sh;
         }
 
+        float anim_progress = 0.0f;
+        if (cg->animation_start_events != 0 && cg->animation_end_duration > 0 && os_window->shader_group_anim[g].active) {
+            double elapsed = (double)(now - os_window->shader_group_anim[g].started_at);
+            double t = elapsed / (double)cg->animation_end_duration;
+            if (t < 0.0) t = 0.0;
+            if (t > 1.0) t = 1.0;
+            anim_progress = (float)(cg->animation_curve ? apply_easing_curve(cg->animation_curve, t, cg->animation_end_duration) : t);
+        }
         glUniform1i(group_loc, (GLint)g);
         glUniform4f(viewport_loc, vp_x, vp_y, vp_w, vp_h);
+        glUniform1f(anim_progress_loc, anim_progress);
         draw_quad(false, 0);
         if (is_last) last_group_rendered = true;
     }

kitty/shaders/custom/bloom.slang

@@ -49,7 +49,8 @@ public float4 fragment_main(
     float4 color,
     KittyTextures t,
     KittyCustomShaderData d,
-    float4 viewport
+    float4 viewport,
+    float animation_progress
 ) {
     float2 uv = t.pos;
 

kitty/shaders/custom/crt.slang

@@ -17,7 +17,8 @@ public float4 fragment_main(
     float4 color,
     KittyTextures t,
     KittyCustomShaderData d,
-    float4 viewport
+    float4 viewport,
+    float animation_progress
 ) {
     // UV within the current viewport (0..1)
     float2 uv = t.pos;

kitty/shaders/custom/pipeline.slang

@@ -59,7 +59,7 @@ float3 linear2srgb(float3 x) {  // vector
 
 uniform Sampler2D backbuffer, a, b, persist;
 
-public float4 pipeline_fragment_main(float2 backbuffer_pos, int group, float4 viewport) {
+public float4 pipeline_fragment_main(float2 backbuffer_pos, int group, float4 viewport, float animation_progress) {
     float4 color = backbuffer.Sample(backbuffer_pos);  // pre multiplied linear RGB
     color = float4(color.rgb / color.a, color.a);  // un pre multiplied color passed through pipeline
     KittyTextures t = {backbuffer, a, b, persist, backbuffer_pos};

kitty/shaders/custom/sample.slang

@@ -17,7 +17,10 @@ public float4 fragment_main(
     // the bottom-left of the screen and y increasing upwards (standard UV
     // coordinates). All numbers are unit floats. If no viewport is defined for
     // the group defaults to (0, 0, 1, 1) that is, the full backbuffer.
-    float4 viewport
+    float4 viewport,
+    // The value after applying the animation easing curve to time since
+    // animation start.
+    float animation_progress
 ) {
     return float4(color.r, min(max(0.1, color.g) * 2, 1), color.b, color.a);
 }

kitty/shaders/custom/tft.slang

@@ -22,7 +22,8 @@ public float4 fragment_main(
     float4 color,
     KittyTextures t,
     KittyCustomShaderData d,
-    float4 viewport
+    float4 viewport,
+    float animation_progress
 ) {
     float2 pixel_pos = t.pos * float2(d.viewport_size_pixels);
     float3 c = color.rgb;

kitty/shaders/slang.py

@@ -1411,7 +1411,9 @@ def build_custom_shader_pipeline_ir(pipeline: Pipeline, cache_dir: str, invocati
 implementing {slot_module_name};
 import kitty_custom_shader_types;
 import {module_name};
-public float4 {entry_point}(float4 inp, KittyTextures t, KittyCustomShaderData d, float4 viewport) {{ return fragment_main(inp, t, d, viewport); }}
+public float4 {entry_point}(
+    float4 inp, KittyTextures t, KittyCustomShaderData d, float4 viewport, float animation_progress
+) {{ return fragment_main(inp, t, d, viewport, animation_progress); }}
 """
         wrappers[f'wrapper{i}.slang'] = wrapper_src
         entry_points.append(entry_point)
@@ -1424,7 +1426,7 @@ public float4 {entry_point}(float4 inp, KittyTextures t, KittyCustomShaderData d
     num_groups = len(pipeline['groups'])
     for g_idx, group in enumerate(pipeline['groups']):
         n = len(group['shaders'])
-        calls = '\n'.join(f'        color = fragment_main{ep_idx + j}(color, t, csd, viewport);' for j in range(n))
+        calls = '\n'.join(f'        color = fragment_main{ep_idx + j}(color, t, csd, viewport, animation_progress);' for j in range(n))
         is_last = g_idx == num_groups - 1
         if is_last:
             calls += '\n        color = float4(linear2srgb(color.rgb), color.a);'
@@ -1482,8 +1484,8 @@ VertexOutput vmain_wrap(uint vertex_id : SV_VertexID) {
 }
 
 [shader("fragment")]
-float4 fmain_wrap(float2 texcoord : TEXCOORD, uniform int group, uniform float4 viewport) : SV_Target {
-    return pipeline_fragment_main(texcoord, group, viewport);
+float4 fmain_wrap(float2 texcoord : TEXCOORD, uniform int group, uniform float4 viewport, uniform float animation_progress) : SV_Target {
+    return pipeline_fragment_main(texcoord, group, viewport, animation_progress);
 }
         """.replace('MODULE', slot.replace('-', '_')).encode()