ClassiCube/misc/dreamcast/VertexTransform.S
2024-10-16 07:10:23 +11:00

231 lines
7.3 KiB
ArmAsm

#define FLG r0 // clip flags
#define TMP r1 // temp
#define VTX r2 // PVR_CMD_VERTEX
#define EOS r3 // PVR_CMD_VERTEX_EOL
#define SRC r4 // src pointer ARG
#define DST r5 // dst pointer ARG
#define CNT r6 // quads count ARG
#define PFT r7 // prefetch address
#define ZERO fr0 // 0.0
#define F_U fr1 // vertex.u
#define F_V fr2 // vertex.v
#define F_C fr3 // vertex.colour
#define F_X fr4 // vertex.x
#define F_Y fr5 // vertex.y
#define F_Z fr6 // vertex.z
#define F_W fr7 // vertex.w
#define XYZW fv4 // vertex.xyzw
! =========================================================
! ========================= TRANSFORM SETUP ===============
! =========================================================
.macro TransformSetup
mov SRC, PFT ! MT, pft = src
add #-32, DST ! EX, dst -= sizeof(VERTEX)
mov #0xE0, VTX ! EX, VTX = 0x00 00 00 E0
pref @PFT ! LS, PREFETCH pft (first vertex)
shll16 VTX ! EX, VTX = 0x00 E0 00 00
shll8 VTX ! EX, VTX = 0xE0 00 00 00 (PVR_CMD_VERTEX)
mov #0xF0, EOS ! EX, EOS = 0x00 00 00 F0
shll16 EOS ! EX, EOS = 0x00 F0 00 00
shll8 EOS ! EX, EOS = 0xF0 00 00 00 (PVR_CMD_VERTEX_EOL)
fldi0 ZERO ! LS, fr0 = 0.0
.endm
.macro TransformEnd
add #32, DST ! EX, DST += sizeof(VERTEX)
rts ! CO, return after executing instruction in delay slot
mov DST, r0 ! MT, r0 = DST
.endm
! =========================================================
! ========================= VERTEX LOADING ================
! =========================================================
.macro LoadColouredVertex
! LOAD XYZ
fmov @SRC+, F_X ! LS, X = src->x
fmov @SRC+, F_Y ! LS, Y = src->y
fmov @SRC+, F_Z ! LS, Z = src->z
fldi1 F_W ! LS, W = 1.0
! PREPARE NEXT VERTEX
add #16, PFT ! EX, pft += VERTEX_STRIDE
pref @PFT ! LS, PREFETCH pft (next vertex)
add #64, DST ! EX, dst += 2 * sizeof(VERTEX)
! TRANSFORM VERTEX
ftrv xmtrx, XYZW ! FE, TRANSFORM(XYZW)
! LOAD ATTRIBUTES
fmov @SRC+, F_C ! LS, C = src->color
.endm
.macro LoadTexturedVertex
! LOAD XYZ
fmov @SRC+, F_X ! LS, X = src->x
fmov @SRC+, F_Y ! LS, Y = src->y
fmov @SRC+, F_Z ! LS, Z = src->z
fldi1 F_W ! LS, W = 1.0
! PREPARE NEXT VERTEX
add #24, PFT ! EX, pft += VERTEX_STRIDE
pref @PFT ! LS, PREFETCH pft (next vertex)
add #64, DST ! EX, dst += 2 * sizeof(VERTEX)
! TRANSFORM VERTEX
ftrv xmtrx, XYZW ! FE, TRANSFORM(XYZW)
! LOAD ATTRIBUTES
fmov @SRC+, F_C ! LS, C = src->color
fmov @SRC+, F_U ! LS, U = src->u
fmov @SRC+, F_V ! LS, V = src->v
.endm
! =========================================================
! ========================= VERTEX OUTPUT =================
! =========================================================
! To take advantage of SH4 dual instruction processing,
! clipflag calculation and vertex output are interleaved
.macro ProcessVertex1
fmov.s F_W,@-DST ! LS, dst->w = W
fmov.s F_C,@-DST ! LS, dst->c = C
fmov.s F_V,@-DST ! LS, dst->v = V
fcmp/gt ZERO, F_Z ! FE, T = Z > 0
fmov.s F_U,@-DST ! LS, dst->u = U
movt FLG ! EX, CLIPFLAGS = T
fmov.s F_Z,@-DST ! LS, dst->z = Z
fmov.s F_Y,@-DST ! LS, dst->y = Y
fmov.s F_X,@-DST ! LS, dst->x = X
mov.l VTX,@-DST ! LS, dst->flags = PVR_CMD_VERTEX
.endm
.macro ProcessVertex2
fmov.s F_W,@-DST ! LS, dst->w = W
fmov.s F_C,@-DST ! LS, dst->c = C
fmov.s F_V,@-DST ! LS, dst->v = V
fcmp/gt ZERO,F_Z ! FE, T = Z > 0
fmov.s F_U,@-DST ! LS, dst->u = U
movt TMP ! EX, tmp = T
fmov.s F_Z,@-DST ! LS, dst->z = Z
add TMP,TMP ! EX, tmp = tmp + tmp
fmov.s F_Y,@-DST ! LS, dst->y = Y
or TMP,FLG ! EX, CLIPFLAGS |= tmp (T << 1)
fmov.s F_X,@-DST ! LS, dst->x = X
mov.l VTX,@-DST ! LS, dst->flags = PVR_CMD_VERTEX
.endm
.macro ProcessVertex3
fmov.s F_W,@-DST ! LS, dst->w = W
fmov.s F_C,@-DST ! LS, dst->c = C
fmov.s F_V,@-DST ! LS, dst->v = V
fcmp/gt ZERO, F_Z ! FE, T = Z > 0
fmov.s F_U,@-DST ! LS, dst->u = U
movt TMP ! EX, tmp = T
fmov.s F_Z,@-DST ! LS, dst->z = Z
fmov.s F_Y,@-DST ! LS, dst->y = Y
shll2 TMP ! EX, tmp = tmp << 2
fmov.s F_X,@-DST ! LS, dst->x = X
or TMP,FLG ! EX, CLIPFLAGS |= tmp (T << 2)
mov.l VTX,@-DST ! LS, dst->flags = PVR_CMD_VERTEX
.endm
.macro ProcessVertex4
fmov.s F_W,@-DST ! LS, dst->w = W
or EOS,FLG ! EX, CLIPFLAGS |= PVR_CMD_VERTEX_EOL
fmov.s F_C,@-DST ! LS, dst->c = C
fmov.s F_V,@-DST ! LS, dst->v = V
fcmp/gt ZERO, F_Z ! FE, T = Z > 0
fmov.s F_U,@-DST ! LS, dst->u = U
movt TMP ! EX, tmp = T
fmov.s F_Z,@-DST ! LS, dst->z = Z
shll2 TMP ! EX, tmp = tmp << 2
fmov.s F_Y,@-DST ! LS, dst->y = Y
add TMP,TMP ! EX, tmp = (tmp << 2) + (tmp << 2) (T << 3)
fmov.s F_X,@-DST ! LS, dst->x = X
or TMP,FLG ! EX, CLIPFLAGS |= tmp (T << 3)
mov.l FLG,@-DST ! LS, dst->flags = PVR_CMD_VERTEX_EOL | CLIPFLAGS
.endm
! =========================================================
! ==================== TEXTURED VERTEX TRANSFORM ==========
! =========================================================
.global _DrawTexturedQuads
.align 4
_DrawTexturedQuads:
! Setup
TransformSetup
.T_TRANSFORM_QUAD:
LoadTexturedVertex
ProcessVertex1
LoadTexturedVertex
ProcessVertex2
LoadTexturedVertex
ProcessVertex3
LoadTexturedVertex
ProcessVertex4
! CLIPFLAGS TESTING
and #15,FLG
cmp/eq #0,FLG ! T = CLIPFLAGS == 0 (all points invisible)
bf/s .T_LOOP_END ! if !T goto LOOP_END
nop
! No points visible case
add #-128, DST ! DST -= 4 * sizeof(VERTEX), move back to prior quad, so that this invisible quad gets overwritten in next iteration
.T_LOOP_END:
dt CNT ! count--; T = count == 0
bf .T_TRANSFORM_QUAD ! if !T then goto T_TRANSFORM_QUAD
nop
TransformEnd
.size _DrawTexturedQuads, .-_DrawTexturedQuads
.type _DrawTexturedQuads, %function
! =========================================================
! ==================== COLOURED VERTEX TRANSFORM ==========
! =========================================================
.global _DrawColouredQuads
.align 4
_DrawColouredQuads:
! Setup
fldi0 F_U ! U = 0
fldi0 F_V ! V = 0
TransformSetup
.C_TRANSFORM_QUAD:
LoadColouredVertex
ProcessVertex1
LoadColouredVertex
ProcessVertex2
LoadColouredVertex
ProcessVertex3
LoadColouredVertex
ProcessVertex4
! CLIPFLAGS TESTING
and #15,FLG
cmp/eq #0,FLG ! T = CLIPFLAGS == 0 (all points invisible)
bf/s .C_LOOP_END ! if !T goto LOOP_END
nop
! No points visible case
add #-128, DST ! dst -= 4 * sizeof(VERTEX), move back to 1 vertex before start of quad
.C_LOOP_END:
dt CNT ! count--; T = count == 0
bf .C_TRANSFORM_QUAD ! if !T then goto TRANSFORM_QUAD
nop
TransformEnd
.size _DrawColouredQuads, .-_DrawColouredQuads
.type _DrawColouredQuads, %function