Entry 133

"Stream 15's effect tasks: the ending's puffs, rocks and shades"

2026-09-25render

Filescrates/piney-stream/src/ending.rscrates/piney-stream/src/effect.rscrates/piney-stream/src/lib.rscrates/piney-stream/src/draw.rscrates/piney-desktop/src/noiz.rscrates/piney-desktop/src/soft.rscrates/piney-draw/src/lib.rscrates/piney-stream/tests/ending.rstools/test_stream_rs.pydocs/engine/stream.md

Stream 15 is the ending, the last in-engine stream whose effect tasks were not ported (121-126). It plays str0580, then str0581. Func_str0580 and Func_str0581 keep the usual ccStrEffectCtrl. Beside it, each has a table of cues that start parts at the scene's objects, and a group of parts:

• puffs of smoke (EFF_x001 of str0580e);
• in Func_str0580, rocks thrown up from the ground (OBJ_se1_6ro*).

docs/engine/stream.md ("Stream 15's effect tasks") has the details.

What the tasks do

• The walker. ccEventObj::SetObj(cue) looks through the table from the entry it last found. Its loop tests are the wrong way round, so it finds a cue only when the cue is the very next entry (or the one before).
• The walker meets the notes. str0580 gives 539, 540 and 541 in one frame, and the task takes a frame's cues last first. 541 and 540 miss, 539 is found, and every later cue misses too. Only 40 of the table's entries ever play: 200 puffs and 138 rocks.
• The rocks are never deleted. A rock's Ctrl asks ccObj::CheckBoundingBox, which gives 1 for a model with no Bbox. The rock models have none. Every rock falls until the task ends, so the part draws grow to 89,116 over the scene.
• The shades. Func_str0581's cue 55 sets two ccBufferSamplings with SetShade. That is REGION_REPEAT on the picture being drawn: 2- and 4-texel blocks, offset a little, at depth 1000. The Z test keeps them off what is nearer. Its feedback goes to that depth too.
• The trails. Func_str0580's feedback sets its offset's y to 0.16. MakePacket adds the offset in sixteenths of the view, so the last frame's picture is drawn 4.5 pixels lower each frame and trails downwards.
• Func_str0580 outlives its scene. After its loop it makes itself eventExTscb2 and passes until the next scene's ccSetStreamDemoThread sets its param[1] to 2. Then it passes three more times. Each frame it passes before Func_str0581.
• The view. The tasks set the scene view's divZ to 2000 and 3000. Func_str0581 sets a black fog (30000 to 50000) every pass, with three sky objects out of it.

The port

• The tasks. piney_stream::ending holds Str0580 and Str0581, the walker, and the parts. The parts give PartDraws. The tasks read the scene's objects through effect::SceneWorld.
• The parts' draws. Stream::draw_parts draws them on sysLayer:
  • a puff through piney_effect::eff::Eff, from str0580e read into the stream's effect assets;
  • a rock with draw::draw_rigid, the scene's model draw split out of draw_node.
• The tail. Stream's tail keeps Func_str0580 after its scene and steps it before the next task.
• The sampler. piney_desktop::noiz::Sampling gained a centre, an offset, a depth, a page and a wrap. Sampling::shade is SetShade, and Ctrl::shades draws them.
• The wrap. piney_draw::Wrap::Region carries REGION_REPEAT. The software rasterizer reads it in blocks; piney-gs samples it as a plain repeat.

Checked

• The fixtures. tools/test_stream_rs.py effects str0580 and str0581 run the game's tasks in eemu. They stand the tables' objects in by name and hook ccEff::Draw and ccObj::Draw to record the parts. The transfer records its note's object, and step 0 records the divZ.
• crates/piney-stream/tests/ending.rs compares the port with them:
  • every pass of str0580 (1,950) and of str0581 (3,218);
  • each pass's primitives, rand, part draws, transfers and the divZ;
  • all equal.
• The divZ. The first port set 500 for Func_str0580, a value misread from Func_str0120's. The code has 2000 (lui 0x44fa). The fixtures did not record a divZ set before the first pass. They do now, and the test takes the value from them.
• Stream 15 played for real (stream15_plays_through):
  • Func_str0580 over the scene's own objects sends the fixture's primitives and draws the fixture's rand to str0580's last frame;
  • the cues come on the same steps;
  • the one transfer comes, and both tasks' divZ.
• Shots. piney-game --mode story:31 --shot OUT --every 30 over the whole ending:
  • the rocks and the puffs fly from 1225 on;
  • the feedback's offset trails come from 1500;
  • str0581's shades and fades show. With and without the parts drawn, frame 1250 differs where the rocks and puffs are.
• The black sky. The brief's black sky and missing ground (the port's frames 90-240) are str0580's own. Its first frames draw only the sky, the clouds and the two figures. OBJ_se1_5bac1's transparency is 0.9 at frame 60, 0 at 90, 0.05 at 120 and 1 by 160. The tasks draw nothing of their own before frame 1225.