good progress, but no other compute pass yet

shaders/agents_cs.glsl

@@ -0,0 +1,36 @@
+#[compute]
+#version 450
+
+// Invocations in the (x, y, z) dimension
+layout(local_size_x = 64, local_size_y = 1, local_size_z = 1) in;
+
+layout(r32f, set = 0, binding = 0) uniform restrict readonly image2D current_trail;
+layout(r32f, set = 1, binding = 0) uniform restrict writeonly image2D output_trail;
+layout(set = 2, binding = 1) restrict buffer AgentBuffer {
+    vec2 positions[];
+} agent_buffer;
+
+layout(push_constant, std430) uniform Params {
+    vec2 texture_size;
+} params;
+
+
+void main() {
+
+    ivec2 size = ivec2(params.texture_size.x - 1, params.texture_size.y - 1);
+    vec2 position = agent_buffer.positions[gl_GlobalInvocationID.x];
+
+    ivec2 uv = ivec2(gl_GlobalInvocationID.xy);
+
+    ivec2 tl = ivec2(0, 0);
+    float current_v = imageLoad(current_trail, clamp(uv - ivec2(0, 1), tl, size)).r;
+    float up_v = imageLoad(current_trail, clamp(uv - ivec2(0, 1), tl, size)).r;
+    float down_v = imageLoad(current_trail, clamp(uv + ivec2(0, 1), tl, size)).r;
+    float left_v = imageLoad(current_trail, clamp(uv - ivec2(1, 0), tl, size)).r;
+    float right_v = imageLoad(current_trail, clamp(uv + ivec2(1, 0), tl, size)).r;
+
+    float new_v = current_v + 0.05;
+
+    vec4 result = vec4(new_v, new_v, new_v, 1.0);
+    imageStore(output_trail, uv, result);
+}