Completed C-side of: Camera Transformation chapter. Now todo atom tape translation...

This commit is contained in:
ed
2026-08-08 16:42:07 -04:00
parent 917b764d95
commit 68b87f1c8b
11 changed files with 268 additions and 108 deletions
+93 -81
View File
@@ -31,6 +31,7 @@
#pragma endregion Duffle Headers
#pragma region Duffle TUs
#include "duffle/pad.c"
#include "duffle/math.atom.c"
#include "duffle/mips.atom.c"
#include "duffle/gte.atom.c"
@@ -62,7 +63,10 @@ typedef Struct_(SMemory) {
U4 MemTape[MemTape_Len];
M3_S2 tform_world;
MT3_S2S4 tform_world;
MT3_S2S4 tform_view;
Camera cam;
Ent_Cube cube;
Ent_Floor floor;
@@ -75,6 +79,9 @@ typedef Struct_(SMemory) {
global SMemory smem;
extern SMemory smem;
#define pad0_btn_(btn) btn & smem.pad[0].buttons
#define pad1_btn_(btn) btn & smem.pad[1].buttons
I_ B1* prim__alloc(U4 type_width, Str8 type_name) {
gknown PrimitiveArena* pa = & smem.primitives;
gknown B1* buf = (B1*) r_(smem.primitives.buf)[smem.active_buf_id];
@@ -85,77 +92,31 @@ I_ B1* prim__alloc(U4 type_width, Str8 type_name) {
}
#define prim_alloc(type) (type*)prim__alloc(S_(type), slit( stringify(type)))
/* Uses ONE 8-byte frame allocated via the compiler's standard prologue.
* The 4 wasted-arg words for B(12h) InitPAD2 live at [SP+0..15] but are not explicitly allocated.
* The compiler handles the MIPS O32 "wasted stack" convention for us by treating the B-call as a 4-arg call.
*
* The buffer pointers are passed as arguments so the compiler keeps them in callee-saved registers;
* The B(12h) asm volatile block does NOT clobber those registers (it clobbers only the volatile GPRs + the B-table arg registers explicitly).
* The C-level writes after the call re-load the pointers from their callee-saved homes.
*
* The clobber list for both B-calls names the full BIOS destroy set documented in kernelbios.md:167-174 (R1..R15, R24..R25, R31, HI/LO).
* The kernel-ABI "volatile GPRs" subset is clb_system; the rest of the destroy set is enumerated explicitly here. */
NI_ void pad_bios_init_start(PadBiosRaw* raw0, PadBiosRaw* raw1)
{
/* Pin raw0 + raw1 to $a0 + $a1 via rgcc; the B(12h) call uses these directly.
* The `(void)` casts mark them as unread after the call so the compiler doesn't need to move them back. */
register PadBiosRaw* p0 rgcc(R_A0) = raw0;
register PadBiosRaw* p1 rgcc(R_A1) = raw1;
(void)p0; (void)p1;
void
resolve_look_at_c11(MT3_S2S4* look_at, V3_S4* eye, V3_S4* target, V3_S4* up_in) {
// TODO(Ed): Want to interpret this under the lens of Eric Lengyel's geometric algebra
V3_S4 right, up, forward;
V3_S4 ux, uy, uz;
V3_S4 pos, off;
// TODO(Ed): Properly annotate the raw values in the inline asm instructions.
// Use enums.
forward = target[0]; sub_v3s4(& forward, eye[0]);
normalize_v3s4(& forward, & uz);
/* B(12h) InitPAD2(raw0, 0x22, raw1, 0x22)
* $a0 = raw0 (rgcc-bound; survives the sequence below)
* $a1 = raw1 (preserved into $a2 before $a1 is overwritten)
* $a2 = raw1 (moved from $a1; survives $a1's overwrite)
* $a3 = 0x22 (immediate)
* $t1 = 0x12 (function number)
* $t2 = 0xB0 (BIOS B-table address) */
asm volatile(
asm_words(
or_u( rarg_2, rarg_1, rdiscard), /* $a2 = $a1 = raw1 */
add_ui( rarg_1, rdiscard, bios_pad_buffer_size), /* $a1 = 0x22 */
add_ui( rarg_3, rdiscard, bios_pad_buffer_size), /* $a3 = 0x22 */
add_ui( rtmp_1, rdiscard, bios_init_pad_2), /* $t1 = 0x12 */
add_ui( rtmp_2, rdiscard, bios_btable_addr), /* $t2 = 0xB0 */
call_reg(rtmp_2), /* jalr $t2, $ra */
nop /* BD slot */
)
asm_rpins, r_use(p0), r_use(p1)
asm_clobber:
rlit(R_AT),
rlit(R_V0), rlit(R_V1),
rlit(R_T0), rlit(R_T1), rlit(R_T2), rlit(R_T3), rlit(R_T4),
rlit(R_T5), rlit(R_T6), rlit(R_T7), rlit(R_T8), rlit(R_T9),
rlit(R_RA),
clb_mem_drain
);
cross_v3s4(& uz, up_in, & right); normalize_v3s4(& right, & ux);
cross_v3s4(& uz, & ux, & up); normalize_v3s4(& up, & uy);
/* The C-level writes re-load the pointers via the parameter names and write 0xFF to each
* buffer's status byte to mark the initial-state hazard documented in kernelbios.md:1621-1624. */
u1_v(raw0)[0] = 0xFF;
u1_v(raw1)[0] = 0xFF;
look_at->m[0][0] = ux.x; look_at->m[0][1] = ux.y; look_at->m[0][2] = ux.z;
look_at->m[1][0] = uy.x; look_at->m[1][1] = uy.y; look_at->m[1][2] = uy.z;
look_at->m[2][0] = uz.x; look_at->m[2][1] = uz.y; look_at->m[2][2] = uz.z;
pos = eye[0]; mul_v3s4(& pos, v3s4(-1,-1,-1));
/* B(13h) StartPAD2() — no args. The BIOS preserves $sp. */
asm volatile(
asm_words(
add_ui( rtmp_1, rdiscard, bios_start_pad_2), /* $t1 = 0x13 */
add_ui( rtmp_2, rdiscard, bios_btable_addr), /* $t2 = 0xB0 (re-load) */
call_reg(rtmp_2), /* jalr $t2, $ra */
nop /* BD slot */
)
asm_clobber:
rlit(R_AT),
rlit(R_V0), rlit(R_V1),
rlit(R_T0), rlit(R_T1), rlit(R_T2), rlit(R_T3), rlit(R_T4),
rlit(R_T5), rlit(R_T6), rlit(R_T7), rlit(R_T8), rlit(R_T9),
rlit(R_RA),
clb_mem_drain
);
mul_m3s2_v3s4(look_at, & pos, & off);
trans_m3s2(look_at, & off);
}
FI_ void camera_look_at_c11(Camera* c, V3_S4* target, V3_S4* up_in) { resolve_look_at_c11(& c->look_at, & c->pos, target, up_in); }
GCC_OPTIMIZATION_DISABLE
void update(PrimitiveArena* pa, U4* ordering_buf)
{
@@ -171,11 +132,36 @@ void update(PrimitiveArena* pa, U4* ordering_buf)
tb_emit_(pad_bios_snapshot);
tb_data_(raw, & smem.pad_raw[1]);
tb_data_(state, & smem.pad[1]);
// Demo input
tb_emit_(pad_apply_input);
tb_data_(state, & smem.pad[0]);
tb_data_(cube_rot, & smem.cube.rot);
tb_data_(floor_rot, & smem.floor.rot);
// TODO(Ed): Implement based on below.
// tb_emit_(pad_input_cam);
// tb_data_(cam, & smem.cam);
if (pad0_btn_(Pad_Left)) {
smem.cam.pos.x -= 50;
}
if (pad0_btn_(Pad_Right)) {
smem.cam.pos.x += 50;
}
if (pad0_btn_(Pad_Up)) {
smem.cam.pos.y -= 50;
}
if (pad0_btn_(Pad_Down)) {
smem.cam.pos.y += 50;
}
if (pad0_btn_(Pad_Cross)) {
smem.cam.pos.z -= 50;
}
if (pad0_btn_(Pad_Circle)) {
smem.cam.pos.z += 50;
}
// Demo input (not longer using)
// tb_emit_(pad_input_cube_rotation);
// tb_data_(state, & smem.pad[0]);
// tb_data_(cube_rot, & smem.cube.rot);
// tb_data_(floor_rot, & smem.floor.rot);
}
}
@@ -202,15 +188,34 @@ void update(PrimitiveArena* pa, U4* ordering_buf)
A2_S2 p; //???
S4 flag; //????
// Camera Look at
if (1)
{
camera_look_at_c11(& smem.cam, & smem.cube.pos, & v3s4(0, -fp_one, 0));
}
// Camera look at (Tape)
if (0)
{
tb.used = 0; tb_scope_run(& tb) {
tb_emit_(resolve_look_at);
// tb_data_();
}
}
// Draw cube
if (1)
{
m3s2_rotation (& smem.cube.rot, & smem.tform_world);
m3s2_translation(& smem.tform_world, & smem.cube.pos);
m3s2_scale (& smem.tform_world, & smem.cube.scale);
gte_matrix_set_rotation (& smem.tform_world);
gte_matrix_set_translation(& smem.tform_world);
mt3s2s4_rotation (& smem.cube.rot, & smem.tform_world);
mt3s2s4_translation(& smem.tform_world, & smem.cube.pos);
mt3s2s4_scale (& smem.tform_world, & smem.cube.scale);
// Combine world and look_at matrix.
gte_comp_coord_m3s2(& smem.cam.look_at, & smem.tform_world, & smem.tform_view);
gte_matrix_set_rotation (& smem.tform_view);
gte_matrix_set_translation(& smem.tform_view);
// gte_matrix_set_rotation (& smem.tform_world);
// gte_matrix_set_translation(& smem.tform_world);
U4 prim_base = u4_(pa->buf[smem.active_buf_id]);
U4 prim_cursor = prim_base + pa->used;
@@ -238,9 +243,15 @@ void update(PrimitiveArena* pa, U4* ordering_buf)
// Draw floor
if (1)
{
m3s2_rotation (& smem.floor.rot, & smem.tform_world);
m3s2_translation(& smem.tform_world, & smem.floor.pos);
m3s2_scale (& smem.tform_world, & smem.floor.scale);
mt3s2s4_rotation (& smem.floor.rot, & smem.tform_world);
mt3s2s4_translation(& smem.tform_world, & smem.floor.pos);
mt3s2s4_scale (& smem.tform_world, & smem.floor.scale);
// Combine world and look_at matrix.
gte_comp_coord_m3s2(& smem.cam.look_at, & smem.tform_world, & smem.tform_view);
gte_matrix_set_rotation (& smem.tform_view);
gte_matrix_set_translation(& smem.tform_view);
U4 prim_base = u4_(pa->buf[smem.active_buf_id]);
U4 prim_cursor = prim_base + pa->used;
@@ -250,8 +261,8 @@ void update(PrimitiveArena* pa, U4* ordering_buf)
// Prepare the tape. (Push protocol to tape)
tb.used = 0; tb_scope(& tb) {
tb_emit(& tb, set_gte_world);
tb_data(& tb, u4_(& smem.tform_world));
// tb_emit(& tb, set_gte_mt3s2s4);
// tb_data(& tb, u4_(& smem.tform_view));
tb_emit(& tb, rbind_floor_f3_face);
// TODO(Ed): Just use a single context struct ref?
@@ -297,6 +308,7 @@ int main(void)
smem.scratchpad = C_(U4_V, 0x1F800000);
// smem.primitives.used = 0;
// smem.active_buf_id = 0;
smem.cam.pos = v3s4(500, -1000, -1500);
/*Persistent Entity Setup*/{
ent_cube128_init(& smem.cube.verts, & smem.cube.faces); {
Ent_Cube* cube = & smem.cube;