104 lines
4.7 KiB
Plaintext
104 lines
4.7 KiB
Plaintext
calc_tight_light_projection :: (camera: Camera, light_direction: Vector3) -> Matrix4 {
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// View space camera frustum
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aspect_ratio := cast(float)engine.renderer.render_target_height / cast(float)engine.renderer.render_target_width;
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frustum := get_frustum(camera.fov, aspect_ratio, camera.z_near, camera.z_far);
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// View frustum back to world space
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inv_camera_view := inverse(camera.view_matrix);
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view_frustum_in_world_space := transform(frustum, inv_camera_view);
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light_view := look_at_lh(.{0,0,0}, light_direction, .{0,1,0});
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light_space_frustum := transform(view_frustum_in_world_space, light_view);
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aabb := get_frustum_aabb(light_space_frustum);
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bottom_left := aabb.min;
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top_right := Vector3.{aabb.max.x, aabb.max.y, aabb.min.z};
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light_pos_world := (bottom_left + top_right) * 0.5;
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inverse_light_view := inverse(light_view);
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light_pos_world = transform_position(light_pos_world, inverse_light_view);
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light_view = look_at_lh(light_pos_world, light_pos_world + light_direction, .{0,1,0});
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light_space_frustum = transform(view_frustum_in_world_space, light_view);
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final_aabb := get_frustum_aabb(light_space_frustum);
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// Texel size calculation based on shadow map resolution (e.g., 2048x2048)
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texel_size_x := (final_aabb.max.x - final_aabb.min.x) / 4096.0;
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texel_size_y := (final_aabb.max.y - final_aabb.min.y) / 4096.0;
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// Snap the minimum bounds of the AABB to the nearest texel
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final_aabb.min.x = floor(final_aabb.min.x / texel_size_x) * texel_size_x;
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final_aabb.min.y = floor(final_aabb.min.y / texel_size_y) * texel_size_y;
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// Recalculate the max bounds based on snapped min
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final_aabb.max.x = final_aabb.min.x + (texel_size_x * 4096.0);
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final_aabb.max.y = final_aabb.min.y + (texel_size_y * 4096.0);
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// Padding
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final_aabb.min -= .{8,5,8};
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final_aabb.max += .{8,50, 8};
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light_projection := orthographic_lh_projection_matrix(final_aabb.min.x, final_aabb.max.x, final_aabb.min.y, final_aabb.max.y, final_aabb.min.z, final_aabb.max.z);
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return light_projection * light_view;
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}
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update_light_buffer :: () {
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scene := engine.current_scene;
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camera := ifx engine.mode == .EDITING then engine.editor.camera else scene.camera;
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light_data : Directional_Light_Buffer_Data;
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light_data.direction = scene.directional_light.direction;
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light_data.color_and_intensity = scene.directional_light.color_and_intensity;
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light_matrix := calc_tight_light_projection(camera, scene.directional_light.direction.xyz);
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light_data.light_matrix = light_matrix;
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upload_data_to_buffer(engine.renderer, engine.directional_light_buffer, *light_data, size_of(Directional_Light_Buffer_Data));
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}
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sync_engine_buffers :: () {
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update_light_buffer();
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// Camera buffer
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camera := ifx engine.mode == .EDITING then *engine.editor.camera else *engine.current_scene.camera;
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camera_data : Camera_Data;
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camera_data.projection_matrix = camera.projection_matrix;
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camera_data.view_matrix = camera.view_matrix;
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camera_data.position = to_v4(camera.position);
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upload_data_to_buffer(engine.renderer, engine.camera_buffer, *camera_data, size_of(Camera_Data));
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shader_time : Shader_Time;
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shader_time.time = time;
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upload_data_to_buffer(engine.renderer, engine.time_buffer, *shader_time, size_of(Shader_Time));
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// Sync entity transforms
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for engine.current_scene.entities {
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if it.flags & .RENDERABLE {
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if it.renderable.type == {
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case .MODEL; {
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for n, i: it.renderable.model.nodes {
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if n.meshes.count > 0 {
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node_data := *it.renderable.nodes[i];
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upload_data_to_buffer(engine.renderer, node_data.transform_buffer, *node_data.transform.world_matrix, size_of(Matrix4));
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if node_data.num_bones > 0 {
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for handle, mesh_index: n.meshes {
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m := parray_get(*engine.renderer.meshes, handle);
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bones : [MAX_BONES] Matrix4;
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for bone_index: 0..m.num_bones-1 {
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bone := *it.renderable.nodes[m.bone_indices[bone_index]];
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bones[bone_index] = bone.transform.world_matrix * m.bone_matrices[bone_index];
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}
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upload_data_to_buffer(engine.renderer, node_data.bone_buffers[mesh_index], bones.data, size_of(Matrix4) * m.num_bones);
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}
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}
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}
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}
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}
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}
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}
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}
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} |