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https://github.com/RetroPortingToolKit/psxrecomp
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Shokunin
dd5fdec6bb
Many PS1 renderers drop a primitive whose depth index falls past the end of their ordering table. Raising that limit can write past the table, so a title can now list such guards in game.toml with the register that carries the index and the last safe value. While a trusted mod has called psx_mod_set_draw_distance_clamp(1), generated main-EXE code clamps that register before the guard runs, so far geometry is kept in the farthest slot instead of popping in later. - Off by default and reset at every session start, so netplay and every title that lists no sites run unchanged; with no sites the generated code and declarations are byte-identical. - Main executable only: the full instruction word is the guard, generation fails on a mismatch or a load-delay hazard, captured overlay code keeps its own code (the sites are not part of the overlay config identity), and the dirty-RAM interpreter applies the clamp where the game's text image holds the listed word. - Compatibility: code_generator.cpp is a codegen-hash input, so the codegen hash and the overlay-cache tag change for every title, sites or not. Savestates from earlier builds are refused, and overlay shards rebuild once on first visit. Generated code and behaviour are unchanged for a title without sites or with the switch off. - Tests: draw_distance_codegen_test (config rules, emission, guards, declarations, overlay identity) and draw_distance_interp_test (store, switch, interpreted guards); the session-reset guard covers the switch. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
72 lines
2.8 KiB
C
72 lines
2.8 KiB
C
/* draw_distance.h - opt-in draw-distance clamps ([[draw_distance.clamp]]).
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*
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* Many PS1 renderers drop a primitive whose depth falls past the end of their
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* ordering table: `sltiu t, z, N; beqz t, reject`. The limit protects the OT,
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* so simply raising it can write past the table. A title lists such
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* predicates in game.toml together with the register that carries the depth
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* index and the last safe value:
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*
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* [[draw_distance.clamp]]
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* address = "0x80061230"
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* expected = "0x2C4A01C0" # sltiu t2, v0, 0x1C0
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* reg = 2 # v0
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* max = 0x1BF
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*
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* While a trusted mod has switched the clamps on, the listed register is
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* clamped to `max` (signed) immediately before the listed instruction runs,
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* so a far primitive is kept in the farthest OT slot instead of being
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* dropped. Off (the default, reset at every session start) the sites run the
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* original code. Main executable only: generated main-EXE code applies the
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* clamp, captured overlay code at the same address keeps its own code, and
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* the dirty-RAM interpreter applies it where the game's text image still
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* holds the listed instruction.
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*
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* docs/config_schema.md "Draw-distance clamps" has the config rules.
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*/
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#ifndef PSX_DRAW_DISTANCE_H
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#define PSX_DRAW_DISTANCE_H
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#include <stdint.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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typedef struct PSXDrawDistanceClampSite {
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uint32_t address; /* any segment; stored physical */
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uint32_t expected; /* the complete instruction word at address */
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uint32_t reg; /* 1..31: a source register of `expected` */
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int32_t max; /* signed upper bound */
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} PSXDrawDistanceClampSite;
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#define PSX_DRAW_DISTANCE_CLAMP_SITES_MAX 256
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/* Nonzero while the clamps are on. Generated main-EXE code reads it at every
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* configured site. */
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extern uint32_t g_psx_draw_distance_clamp;
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/* On and at least one site configured: the interpreter's per-instruction
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* gate. */
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extern int g_psx_draw_distance_clamp_live;
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/* The title's sites (game config). Copied, sorted, capped at
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* PSX_DRAW_DISTANCE_CLAMP_SITES_MAX (a longer list is logged). Returns the
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* number kept. */
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int psx_draw_distance_set_clamp_sites(const PSXDrawDistanceClampSite *sites,
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int count);
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int psx_draw_distance_clamp_site_count(void);
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/* The site at `pc` whose instruction is `insn`, or NULL. */
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const PSXDrawDistanceClampSite *psx_draw_distance_clamp_find(uint32_t pc,
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uint32_t insn);
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/* The value the clamp leaves in the register. */
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static inline uint32_t psx_draw_distance_clamp_value(uint32_t value,
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int32_t max) {
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return (int32_t)value > max ? (uint32_t)max : value;
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}
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#ifdef __cplusplus
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}
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#endif
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#endif /* PSX_DRAW_DISTANCE_H */
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