fix: don't draw particles on top of target position

Author: sphamba

lua/smear_cursor/animation.lua

@@ -252,8 +252,10 @@ local function update_particles(time_interval)
 			table.remove(particles, i)
 		else
 			particle.velocity[1] = particle.velocity[1] * velocity_conservation_factor
-				+ config.particle_gravity * (time_interval / 1000)
+				+ (config.particle_gravity + config.particle_random_velocity * (math.random() - 0.5))
+					* (time_interval / 1000)
 			particle.velocity[2] = particle.velocity[2] * velocity_conservation_factor
+				+ config.particle_random_velocity * (math.random() - 0.5) * (time_interval / 1000)
 			particle.position[1] = particle.position[1]
 				+ (particle.velocity[1] * (time_interval / 1000)) / draw.BLOCK_ASPECT_RATIO
 			particle.position[2] = particle.position[2] + (particle.velocity[2] * (time_interval / 1000))
@@ -420,7 +422,12 @@ local function animate()
 		or math.abs(target_center[2] - current_center[2]) < 1 / 8
 	local drawn_corners = straight_line and current_corners or shrink_volume(current_corners)
 
-	local target_reached = false
+	local target_reached = (
+		current_center[1] >= target_corners[1][1]
+		and current_center[1] <= target_corners[3][1]
+		and current_center[2] >= target_corners[1][2]
+		and current_center[2] <= target_corners[3][2]
+	)
 	for i = 1, 4 do
 		-- stylua: ignore
 		if (
@@ -451,7 +458,7 @@ local function animate()
 		gradient_length_squared > 1 and gradient_direction[2] / gradient_length_squared or 0,
 	}
 
-	draw.draw_particles(particles)
+	draw.draw_particles(particles, target_position)
 	draw.draw_quad(drawn_corners, target_position, cursor_is_vertical_bar(), gradient_origin, gradient_direction_scaled)
 	redraw_cmd_mode(must_redraw_cmd_mode)
 end

lua/smear_cursor/config.lua

@@ -147,6 +147,7 @@ M.particle_max_lifetime = 300 -- milliseconds
 M.particle_lifetime_distribution_exponent = 5
 M.particle_max_initial_velocity = 10 -- characters width per second
 M.particle_velocity_from_cursor = 0.2 -- 0: none, 1: full
+M.particle_random_velocity = 100 -- characters width per second
 M.particle_damping = 0.2
 M.particle_gravity = 20 -- characters width per second squared
 M.min_distance_emit_particles = 1.5 -- character widths

lua/smear_cursor/draw.lua

@@ -891,7 +891,8 @@ local function draw_braille_character(row, col, cell, hl_group, zindex)
 	M.draw_character(row, col, braille_characters[braille_index], hl_group, zindex)
 end
 
-M.draw_particles = function(particles)
+M.draw_particles = function(particles, target_position)
+	if target_position == nil then target_position = { 0, 0 } end
 	local cells = {}
 
 	for _, particle in ipairs(particles) do
@@ -908,6 +909,8 @@ M.draw_particles = function(particles)
 
 	for row, row_cells in pairs(cells) do
 		for col, cell in pairs(row_cells) do
+			if row == target_position[1] and col == target_position[2] then goto continue end
+
 			local num_dots = (cell[1][1] > 0 and 1 or 0)
 				+ (cell[2][1] > 0 and 1 or 0)
 				+ (cell[3][1] > 0 and 1 or 0)
@@ -927,15 +930,17 @@ M.draw_particles = function(particles)
 			local shade = math.min(1, lifetime_sum / num_dots / config.particle_max_lifetime)
 			local hl_group_index = round(shade * config.color_levels)
 
-			if hl_group_index > 0 then
-				draw_braille_character(
-					row,
-					col,
-					cell,
-					color.get_hl_group({ level = hl_group_index }),
-					config.windows_zindex - 1
-				)
-			end
+			if hl_group_index == 0 then goto continue end
+
+			draw_braille_character(
+				row,
+				col,
+				cell,
+				color.get_hl_group({ level = hl_group_index }),
+				config.windows_zindex - 1
+			)
+
+			::continue::
 		end
 	end
 end