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dreamcast2: add sierpinski_tetrahedron_fsaa

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This commit is contained in:
Zack Buhman 2025-08-28 13:27:59 -05:00
parent 9108c6a9c1
commit 9b7eae231a
5 changed files with 507 additions and 1 deletions
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7
dreamcast2/example/example.mk
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@ -59,3 +59,10 @@ SIERPINSKI_TETRAHEDRON_OBJ = \
example/sierpinski_tetrahedron.elf: LDSCRIPT = $(LIB)/main.lds example/sierpinski_tetrahedron.elf: LDSCRIPT = $(LIB)/main.lds
example/sierpinski_tetrahedron.elf: $(START_OBJ) $(SIERPINSKI_TETRAHEDRON_OBJ) example/sierpinski_tetrahedron.elf: $(START_OBJ) $(SIERPINSKI_TETRAHEDRON_OBJ)
SIERPINSKI_TETRAHEDRON_FSAA_OBJ = \
holly/core/region_array.o \
example/sierpinski_tetrahedron_fsaa.o
example/sierpinski_tetrahedron_fsaa.elf: LDSCRIPT = $(LIB)/main.lds
example/sierpinski_tetrahedron_fsaa.elf: $(START_OBJ) $(SIERPINSKI_TETRAHEDRON_FSAA_OBJ)

3
dreamcast2/example/sierpinski_tetrahedron.cpp
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@ -464,6 +464,9 @@ void main()
systembus.ISTNRM = istnrm::end_of_transferring_opaque_list; systembus.ISTNRM = istnrm::end_of_transferring_opaque_list;
holly.FB_W_SOF1 = framebuffer_start[i & 1]; holly.FB_W_SOF1 = framebuffer_start[i & 1];
holly.SCALER_CTL = scaler_ctl::vertical_scale_factor(0x0400);
// start the actual render--the rendering process begins by interpreting the // start the actual render--the rendering process begins by interpreting the
// region array // region array
holly.STARTRENDER = 1; holly.STARTRENDER = 1;

496
dreamcast2/example/sierpinski_tetrahedron_fsaa.cpp Normal file
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@ -0,0 +1,496 @@
#include "memorymap.hpp"
#include "holly/core/object_list_bits.hpp"
#include "holly/core/region_array.hpp"
#include "holly/core/region_array_bits.hpp"
#include "holly/core/parameter_bits.hpp"
#include "holly/core/parameter.hpp"
#include "holly/ta/global_parameter.hpp"
#include "holly/ta/vertex_parameter.hpp"
#include "holly/ta/parameter_bits.hpp"
#include "holly/holly.hpp"
#include "holly/holly_bits.hpp"
#include "sh7091/sh7091.hpp"
#include "sh7091/sh7091_bits.hpp"
#include "sh7091/pref.hpp"
#include "sh7091/store_queue_transfer.hpp"
#include "systembus/systembus.hpp"
#include "systembus/systembus_bits.hpp"
// A blue
// B black
// C red
// D green
// A blue
// B black
struct vec3 {
union {
float x;
float r;
};
union {
float y;
float g;
};
union {
float z;
float b;
};
};
struct vertex {
vec3 position;
vec3 color;
};
constexpr float s = 2.5;
static const vertex tetrahedron_vertex[] = {
{{ 0.500000 * s, -0.204124 * s, 0.288675 * s}, {0.0000, 0.0000, 1.0000}},
{{ 0.000000 * s, -0.204124 * s, -0.577350 * s}, {0.0000, 0.0000, 0.0000}},
{{-0.500000 * s, -0.204124 * s, 0.288675 * s}, {1.0000, 0.0000, 0.0000}},
{{ 0.000000 * s, 0.612372 * s, 0.000000 * s}, {0.0000, 1.0000, 0.0000}},
};
void transfer_background_polygon(uint32_t isp_tsp_parameter_start)
{
using namespace holly::core::parameter;
using parameter = isp_tsp_parameter<3>;
volatile parameter * polygon = (volatile parameter *)&texture_memory32[isp_tsp_parameter_start];
polygon->isp_tsp_instruction_word = isp_tsp_instruction_word::depth_compare_mode::always
| isp_tsp_instruction_word::culling_mode::no_culling;
polygon->tsp_instruction_word = tsp_instruction_word::src_alpha_instr::one
| tsp_instruction_word::dst_alpha_instr::zero
| tsp_instruction_word::fog_control::no_fog;
polygon->texture_control_word = 0;
polygon->vertex[0].x = 0.0f;
polygon->vertex[0].y = 0.0f;
polygon->vertex[0].z = 0.00001f;
polygon->vertex[0].base_color = 0xff00ff;
polygon->vertex[1].x = 32.0f;
polygon->vertex[1].y = 0.0f;
polygon->vertex[1].z = 0.00001f;
polygon->vertex[1].base_color = 0xff00ff;
polygon->vertex[2].x = 32.0f;
polygon->vertex[2].y = 32.0f;
polygon->vertex[2].z = 0.00001f;
polygon->vertex[2].base_color = 0xff00ff;
}
static inline uint32_t transfer_ta_global_end_of_list(uint32_t store_queue_ix)
{
using namespace holly::ta;
using namespace holly::ta::parameter;
//
// TA "end of list" global transfer
//
volatile global_parameter::end_of_list * end_of_list = (volatile global_parameter::end_of_list *)&store_queue[store_queue_ix];
store_queue_ix += (sizeof (global_parameter::end_of_list));
end_of_list->parameter_control_word = parameter_control_word::para_type::end_of_list;
// start store queue transfer of `end_of_list` to the TA
pref(end_of_list);
return store_queue_ix;
}
static inline uint32_t transfer_ta_global_polygon(uint32_t store_queue_ix)
{
using namespace holly::core::parameter;
using namespace holly::ta;
using namespace holly::ta::parameter;
//
// TA polygon global transfer
//
volatile global_parameter::polygon_type_0 * polygon = (volatile global_parameter::polygon_type_0 *)&store_queue[store_queue_ix];
store_queue_ix += (sizeof (global_parameter::polygon_type_0));
polygon->parameter_control_word = parameter_control_word::para_type::polygon_or_modifier_volume
| parameter_control_word::list_type::opaque
| parameter_control_word::col_type::floating_color
| parameter_control_word::gouraud;
polygon->isp_tsp_instruction_word = isp_tsp_instruction_word::depth_compare_mode::greater
| isp_tsp_instruction_word::culling_mode::cull_if_negative;
// Note that it is not possible to use
// ISP_TSP_INSTRUCTION_WORD::GOURAUD_SHADING in this isp_tsp_instruction_word,
// because `gouraud` is one of the bits overwritten by the value in
// parameter_control_word. See DCDBSysArc990907E.pdf page 200.
polygon->tsp_instruction_word = tsp_instruction_word::src_alpha_instr::one
| tsp_instruction_word::dst_alpha_instr::zero
| tsp_instruction_word::fog_control::no_fog;
polygon->texture_control_word = 0;
polygon->data_size_for_sort_dma = 0;
polygon->next_address_for_sort_dma = 0;
// start store queue transfer of `polygon` to the TA
pref(polygon);
return store_queue_ix;
}
static inline uint32_t transfer_ta_vertex_tetrahedron(uint32_t store_queue_ix,
const vec3& ap, const vec3& ac,
const vec3& bp, const vec3& bc,
const vec3& cp, const vec3& cc,
const vec3& dp, const vec3& dc)
{
using namespace holly::ta;
using namespace holly::ta::parameter;
if (ap.z <= 0 || bp.z <= 0 || cp.z <= 0 || dp.z <= 0)
return store_queue_ix;
//
// TA polygon vertex transfer
//
volatile vertex_parameter::polygon_type_1 * vertex = (volatile vertex_parameter::polygon_type_1 *)&store_queue[store_queue_ix];
store_queue_ix += (sizeof (vertex_parameter::polygon_type_1)) * 6;
#define transfer_vertex(n, p, c, pcw) \
vertex[n].parameter_control_word = pcw; \
vertex[n].x = p.x; \
vertex[n].y = p.y; \
vertex[n].z = p.z; \
vertex[n].base_color_r = c.r; \
vertex[n].base_color_g = c.g; \
vertex[n].base_color_b = c.b; \
pref(&vertex[n]);
transfer_vertex(0, ap, ac, parameter_control_word::para_type::vertex_parameter);
transfer_vertex(1, bp, bc, parameter_control_word::para_type::vertex_parameter);
transfer_vertex(2, cp, cc, parameter_control_word::para_type::vertex_parameter);
transfer_vertex(3, dp, dc, parameter_control_word::para_type::vertex_parameter);
transfer_vertex(4, ap, ac, parameter_control_word::para_type::vertex_parameter);
transfer_vertex(5, bp, bc, parameter_control_word::para_type::vertex_parameter | parameter_control_word::end_of_strip);
#undef transfer_vertex
return store_queue_ix;
}
#define cos(n) __builtin_cosf(n)
#define sin(n) __builtin_sinf(n)
static float theta = 0;
static inline vec3 vertex_rotate(vec3 v, float cost, float sint)
{
// to make the cube's appearance more interesting, rotate the vertex on two
// axes
float x0 = v.x;
float y0 = v.y;
float z0 = v.z;
float x1 = x0 * cost - z0 * sint;
float y1 = y0;
float z1 = x0 * sint + z0 * cost;
float x2 = x1;
float y2 = y1 * cost - z1 * sint;
float z2 = y1 * sint + z1 * cost;
return (vec3){x2, y2, z2};
}
static inline vec3 vertex_perspective_divide(vec3 v)
{
float w = 1.0f / (v.z + 1.f);
return (vec3){v.x * w, v.y * w, w};
}
static inline vec3 vertex_screen_space(vec3 v)
{
return (vec3){
v.x * 480.f + 640.f,
v.y * 240.f + 240.f,
v.z,
};
}
static uint32_t store_queue_ix = 0;
static float cost;
static float sint;
static inline void tetrahedron(vec3 a, vec3 b, vec3 c, vec3 d)
{
vec3 ap = vertex_screen_space(
vertex_perspective_divide(
vertex_rotate(a, cost, sint)));
vec3 bp = vertex_screen_space(
vertex_perspective_divide(
vertex_rotate(b, cost, sint)));
vec3 cp = vertex_screen_space(
vertex_perspective_divide(
vertex_rotate(c, cost, sint)));
vec3 dp = vertex_screen_space(
vertex_perspective_divide(
vertex_rotate(d, cost, sint)));
const vec3& ac = tetrahedron_vertex[0].color;
const vec3& bc = tetrahedron_vertex[1].color;
const vec3& cc = tetrahedron_vertex[2].color;
const vec3& dc = tetrahedron_vertex[3].color;
store_queue_ix = transfer_ta_vertex_tetrahedron(store_queue_ix,
ap, ac,
bp, bc,
cp, cc,
dp, dc);
}
static inline vec3 midpoint(const vec3& a, const vec3& b)
{
return {(a.x + b.x) * 0.5f,
(a.y + b.y) * 0.5f,
(a.z + b.z) * 0.5f};
}
static void subdivide(vec3 a, vec3 b, vec3 c, vec3 d,
int depth)
{
if (depth == 0) {
tetrahedron(a, b, c, d);
} else {
/*
B
/ \
A---C
*/
vec3 ab = midpoint(a, b);
vec3 ac = midpoint(a, c);
vec3 ad = midpoint(a, d);
vec3 bc = midpoint(b, c);
vec3 bd = midpoint(b, d);
vec3 cd = midpoint(c, d);
/*
b ----
/ \ \
ab bc \
/ \ \
a---ac---c--cd--d
*/
subdivide( a, ab, ac, ad, depth - 1);
subdivide(ab, b, bc, bd, depth - 1);
subdivide(ac, bc, c, cd, depth - 1);
subdivide(ad, bd, cd, d, depth - 1);
}
}
void transfer_ta_sierpinski_tetrahedron()
{
{
using namespace sh7091;
using sh7091::sh7091;
// set the store queue destination address to the TA Polygon Converter FIFO
sh7091.CCN.QACR0 = sh7091::ccn::qacr0::address(ta_fifo_polygon_converter);
sh7091.CCN.QACR1 = sh7091::ccn::qacr1::address(ta_fifo_polygon_converter);
}
store_queue_ix = 0;
store_queue_ix = transfer_ta_global_polygon(store_queue_ix);
cost = cos(theta);
sint = sin(theta);
subdivide(tetrahedron_vertex[0].position,
tetrahedron_vertex[1].position,
tetrahedron_vertex[2].position,
tetrahedron_vertex[3].position,
6);
store_queue_ix = transfer_ta_global_end_of_list(store_queue_ix);
}
void main()
{
/*
a very simple memory map:
the ordering within texture memory is not significant, and could be
anything
*/
uint32_t framebuffer_start[2] = {0x000000, 0x12c000};
uint32_t region_array_start = 0x258000;
uint32_t isp_tsp_parameter_start = 0x400000;
uint32_t object_list_start = 0x300000;
const int tile_y_num = 480 / 32;
const int tile_x_num = 1280 / 32;
using namespace holly::core;
region_array::list_block_size list_block_size = {
.opaque = 8 * 4,
};
region_array::transfer(tile_x_num,
tile_y_num,
list_block_size,
region_array_start,
object_list_start);
transfer_background_polygon(isp_tsp_parameter_start);
//////////////////////////////////////////////////////////////////////////////
// configure the TA
//////////////////////////////////////////////////////////////////////////////
using namespace holly;
using holly::holly;
// TA_GLOB_TILE_CLIP restricts which "object pointer blocks" are written
// to.
//
// This can also be used to implement "windowing", as long as the desired
// window size happens to be a multiple of 32 pixels. The "User Tile Clip" TA
// control parameter can also ~equivalently be used as many times as desired
// within a single TA initialization to produce an identical effect.
//
// See DCDBSysArc990907E.pdf page 183.
holly.TA_GLOB_TILE_CLIP = ta_glob_tile_clip::tile_y_num(tile_y_num - 1)
| ta_glob_tile_clip::tile_x_num(tile_x_num - 1);
// While CORE supports arbitrary-length object lists, the TA uses "object
// pointer blocks" as a memory allocation strategy. These fixed-length blocks
// can still have infinite length via "object pointer block links". This
// mechanism is illustrated in DCDBSysArc990907E.pdf page 188.
holly.TA_ALLOC_CTRL = ta_alloc_ctrl::opb_mode::increasing_addresses
| ta_alloc_ctrl::o_opb::_8x4byte;
// While building object lists, the TA contains an internal index (exposed as
// the read-only TA_ITP_CURRENT) for the next address that new ISP/TSP will be
// stored at. The initial value of this index is TA_ISP_BASE.
// reserve space in ISP/TSP parameters for the background parameter
using polygon = holly::core::parameter::isp_tsp_parameter<3>;
uint32_t ta_isp_base_offset = (sizeof (polygon)) * 1;
holly.TA_ISP_BASE = isp_tsp_parameter_start + ta_isp_base_offset;
holly.TA_ISP_LIMIT = isp_tsp_parameter_start + 0x400000;
// Similarly, the TA also contains, for up to 600 tiles, an internal index for
// the next address that an object list entry will be stored for each
// tile. These internal indicies are partially exposed via the read-only
// TA_OL_POINTERS.
holly.TA_OL_BASE = object_list_start;
// TA_OL_LIMIT, DCDBSysArc990907E.pdf page 385:
//
// > Because the TA may automatically store data in the address that is
// > specified by this register, it must not be used for other data. For
// > example, the address specified here must not be the same as the address
// > in the TA_ISP_BASE register.
holly.TA_OL_LIMIT = object_list_start + 0x200000 - 32;
holly.TA_NEXT_OPB_INIT = (object_list_start + 8 * 4 * tile_y_num * tile_x_num);
//////////////////////////////////////////////////////////////////////////////
// configure CORE
//////////////////////////////////////////////////////////////////////////////
// REGION_BASE is the (texture memory-relative) address of the region array.
holly.REGION_BASE = region_array_start;
// PARAM_BASE is the (texture memory-relative) address of ISP/TSP parameters.
// Anything that references an ISP/TSP parameter does so relative to this
// address (and not relative to the beginning of texture memory).
holly.PARAM_BASE = isp_tsp_parameter_start;
// Set the offset of the background ISP/TSP parameter, relative to PARAM_BASE
// SKIP is related to the size of each vertex
uint32_t background_offset = 0;
holly.ISP_BACKGND_T = isp_backgnd_t::tag_address(background_offset / 4)
| isp_backgnd_t::tag_offset(0)
| isp_backgnd_t::skip(1);
theta = 0;
// draw 500 frames of cube rotation
for (int i = 0; i < 1000; i++) {
//////////////////////////////////////////////////////////////////////////////
// transfer cube to texture memory via the TA polygon converter FIFO
//////////////////////////////////////////////////////////////////////////////
// TA_LIST_INIT needs to be written (every frame) prior to the first FIFO
// write.
holly.TA_LIST_INIT = ta_list_init::list_init;
// dummy TA_LIST_INIT read; DCDBSysArc990907E.pdf in multiple places says this
// step is required.
volatile uint32_t init = holly.TA_LIST_INIT;
(void)init;
transfer_ta_sierpinski_tetrahedron();
//////////////////////////////////////////////////////////////////////////////
// start the actual rasterization
//////////////////////////////////////////////////////////////////////////////
using systembus::systembus;
using namespace systembus;
while ((systembus.ISTNRM & istnrm::end_of_transferring_opaque_list) == 0);
systembus.ISTNRM = istnrm::end_of_transferring_opaque_list;
holly.FB_W_SOF1 = framebuffer_start[i & 1];
holly.SCALER_CTL = scaler_ctl::horizontal_scaling_enable
| scaler_ctl::vertical_scale_factor(0x0400);
// start the actual render--the rendering process begins by interpreting the
// region array
holly.STARTRENDER = 1;
while ((systembus.ISTNRM & istnrm::end_of_render_tsp) == 0);
systembus.ISTNRM = istnrm::end_of_render_tsp
| istnrm::end_of_render_isp
| istnrm::end_of_render_video;
// increment theta for the cube rotation animation
// (used by the `vertex_rotate` function)
theta += 0.001f;
//////////////////////////////////////////////////////////////////////////////
// wait for vertical synchronization
//////////////////////////////////////////////////////////////////////////////
while ((spg_status::vsync(holly.SPG_STATUS)));
while (!(spg_status::vsync(holly.SPG_STATUS)));
holly.FB_R_SOF1 = framebuffer_start[i & 1];
}
// return from main; this will effectively jump back to the serial loader
}

2
dreamcast2/holly/holly_bits.hpp
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@ -526,7 +526,7 @@ namespace holly {
namespace ta_glob_tile_clip { namespace ta_glob_tile_clip {
constexpr inline uint32_t tile_y_num(uint32_t num) { return (num & 0xf) << 16; } constexpr inline uint32_t tile_y_num(uint32_t num) { return (num & 0xf) << 16; }
constexpr inline uint32_t tile_x_num(uint32_t num) { return (num & 0x1f) << 0; } constexpr inline uint32_t tile_x_num(uint32_t num) { return (num & 0x3f) << 0; }
} }
namespace ta_alloc_ctrl { namespace ta_alloc_ctrl {

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dreamcast2/regs/holly/holly_bits.ods
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