extra-animations: burn: Enhance effect by allowing flames to overflow on the sides

Author: soreau

metadata/extra-animations.xml

@@ -78,7 +78,7 @@
 			<option name="burn_flame_speed" type="double">
 				<_short>Burn flame speed</_short>
 				<_long>The speed at which the flames flicker.</_long>
-				<default>5</default>
+				<default>7</default>
 				<min>1</min>
 				<max>100</max>
 				<precision>1</precision>

src/extra-animations/burn.hpp

@@ -140,15 +140,17 @@ void main()
 
     vec3 col = vec3(1.5 * c1, 1.5 * c1 * c1 * c1, c1 * c1 * c1 * c1 * c1 * c1);
 
-    float a = clamp(c * (1.0 - pow(uvpos.y, 3.0)), 0.0, 1.0);
+    float a = clamp(c * (1.0 - pow(uvpos.y, 10.0)), 0.0, 1.0);
     vec4 wfrag = get_pixel(uvpos);
-    float wa = wfrag.a;
     if (uvpos.y < progress)
     {
         wfrag = vec4(0.0);
     }
+    float side_dither = width * 0.0025;
     a *= clamp(progress * 10.0, 0.0, 1.0);
-    vec4 color = vec4(col * wa, wa) * a;
+    a *= pow(clamp(uvpos.x * side_dither * 4.0 + side_dither * 0.2, 0.0, 1.0), side_dither);
+    a *= pow(clamp(((1.0 - uvpos.x) * side_dither * 4.0) + side_dither * 0.2, 0.0, 1.0), side_dither);
+    vec4 color = vec4(col * a, a);
     gl_FragColor = color + wfrag * (1.0 - a);
 }
 )";
@@ -223,7 +225,7 @@ class burn_transformer : public wf::scene::view_2d_transformer_t
         void render(const wf::scene::render_instruction_t& data) override
         {
             auto bb  = self->get_children_bounding_box();
-            auto pbb = self->get_bounding_box();
+            auto pbb = self->get_padded_bounding_box();
             auto tex = wf::gles_texture_t{get_texture(1.0)};
 
             const float vertices[] = {
@@ -294,7 +296,7 @@ class burn_transformer : public wf::scene::view_2d_transformer_t
                     wf::gles::render_target_logic_scissor(data.target, wlr_box_from_pixman_box(box));
                     OpenGL::render_transformed_texture(final_tex, pbb,
                         wf::gles::render_target_orthographic_projection(data.target),
-                        glm::vec4(1.0, 1.0, 1.0, 1.0 / (1.0 + pow(2.718, -(progress * 15.0 - 3.0)))), 0);
+                        glm::vec4(1.0, 1.0, 1.0, std::clamp((progress - 0.07) * 10.0, 0.0, 1.0)), 0);
                 }
 
                 GL_CALL(glBindTexture(GL_TEXTURE_2D, 0));
@@ -321,6 +323,22 @@ class burn_transformer : public wf::scene::view_2d_transformer_t
         });
     }
 
+    wf::geometry_t get_padded_bounding_box()
+    {
+        auto box     = this->get_children_bounding_box();
+        auto padding = 50;
+        box.x     -= padding;
+        box.y     -= padding;
+        box.width += padding * 2;
+        box.height += padding * 2;
+        return box;
+    }
+
+    wf::geometry_t get_bounding_box() override
+    {
+        return get_padded_bounding_box();
+    }
+
     wf::effect_hook_t pre_hook = [=] ()
     {
         output->render->damage(this->get_bounding_box());