example: add clipping2

Unlike the previous clipping example, this clipping example preserves
surface normals.

example/clipping2.cpp

@@ -0,0 +1,294 @@
+#include <cstdint>
+#include <bit>
+
+#include "align.hpp"
+
+#include "vga.hpp"
+#include "holly/holly.hpp"
+#include "holly/core.hpp"
+#include "holly/core_bits.hpp"
+#include "holly/ta_fifo_polygon_converter.hpp"
+#include "holly/ta_parameter.hpp"
+#include "holly/ta_vertex_parameter.hpp"
+#include "holly/ta_global_parameter.hpp"
+#include "holly/ta_bits.hpp"
+#include "holly/isp_tsp.hpp"
+#include "holly/region_array.hpp"
+#include "holly/background.hpp"
+#include "holly/texture_memory_alloc.hpp"
+#include "memorymap.hpp"
+#include "sh7091/serial.hpp"
+
+#include "geometry/triangle.hpp"
+#include "geometry/circle.hpp"
+#include "math/vec4.hpp"
+#include "math/math.hpp"
+#include "math/geometry.hpp"
+
+#include "maple/maple.hpp"
+#include "maple/maple_impl.hpp"
+#include "maple/maple_bus_bits.hpp"
+#include "maple/maple_bus_commands.hpp"
+#include "maple/maple_bus_ft0.hpp"
+
+uint32_t _command_buf[1024 / 4 + 32];
+uint32_t _receive_buf[1024 / 4 + 32];
+
+static ft0::data_transfer::data_format data[4];
+
+void do_get_condition(uint32_t * command_buf,
+		      uint32_t * receive_buf)
+{
+  using command_type = get_condition;
+  using response_type = data_transfer<ft0::data_transfer::data_format>;
+
+  get_condition::data_fields data_fields = {
+    .function_type = std::byteswap(function_type::controller)
+  };
+
+  maple::init_host_command_all_ports<command_type, response_type>(command_buf, receive_buf,
+								  data_fields);
+  maple::dma_start(command_buf);
+
+  using command_response_type = struct maple::command_response<response_type::data_fields>;
+  for (uint8_t port = 0; port < 4; port++) {
+    auto response = reinterpret_cast<command_response_type *>(receive_buf);
+    auto& bus_data = response[port].bus_data;
+    if (bus_data.command_code != response_type::command_code) {
+      return;
+    }
+    auto& data_fields = bus_data.data_fields;
+    if ((data_fields.function_type & std::byteswap(function_type::controller)) == 0) {
+      return;
+    }
+
+    data[port].analog_axis_1 = data_fields.data.analog_axis_1;
+    data[port].analog_axis_2 = data_fields.data.analog_axis_2;
+    data[port].analog_axis_3 = data_fields.data.analog_axis_3;
+    data[port].analog_axis_4 = data_fields.data.analog_axis_4;
+  }
+}
+
+constexpr vec3 colors[] = {
+  {1.f, 0.5f, 0.f},
+  {0.f, 1.0f, 0.f},
+  {0.f, 0.5f, 1.f},
+  {1.f, 0.0f, 1.f},
+};
+
+void transform1(ta_parameter_writer& parameter,
+		const vec3& v,
+		const vec3& c,
+		bool end_of_strip)
+{
+  float x = v.x;
+  float y = v.y;
+  float z = v.z;
+
+  // camera transform
+  z += 1;
+
+  // screen space transform
+  x *= 240.f;
+  y *= 240.f;
+  x += 320.f;
+  y += 240.f;
+  z = 1 / z;
+
+  parameter.append<ta_vertex_parameter::polygon_type_1>() =
+    ta_vertex_parameter::polygon_type_1(polygon_vertex_parameter_control_word(end_of_strip),
+					x, y, z,
+					1.0f, // alpha
+					c.r,
+					c.g,
+					c.b
+					);
+
+}
+
+void transform(ta_parameter_writer& parameter,
+	       const vec3 * vertices,
+	       const face_vn& face,
+	       const vec4& color,
+	       const vec3& position,
+	       const float theta,
+	       const bool enable_clipping
+	       )
+{
+  const uint32_t parameter_control_word = para_control::para_type::polygon_or_modifier_volume
+                                        | para_control::list_type::opaque
+                                        | obj_control::col_type::floating_color
+                                        | obj_control::gouraud;
+
+  const uint32_t isp_tsp_instruction_word = isp_tsp_instruction_word::depth_compare_mode::greater
+                                          | isp_tsp_instruction_word::culling_mode::no_culling;
+
+  const uint32_t tsp_instruction_word = tsp_instruction_word::src_alpha_instr::one
+                                      | tsp_instruction_word::dst_alpha_instr::zero
+                                      | tsp_instruction_word::fog_control::no_fog;
+
+  constexpr uint32_t strip_length = 3;
+  vec3 points[strip_length];
+
+  // object transform and clip
+  for (uint32_t i = 0; i < strip_length; i++) {
+    uint32_t vertex_ix = face[i].vertex;
+    auto vertex = vertices[vertex_ix];
+
+    vertex = (vertex * 0.5f);
+
+    // rotate 90° around the X axis
+    //float x = vertex.x;
+    //float y = vertex.z;
+    //float z = vertex.y;
+
+    float x = vertex.x * cos(theta) - vertex.z * sin(theta);
+    float y = vertex.x * sin(theta) + vertex.z * cos(theta);
+    float z = vertex.y;
+
+    // object transform
+    x += position.x; // object space
+    y += position.y; // object space
+    z += position.z; // object space
+
+    // clip
+    points[i] = vec3(x, y, z);
+  }
+
+  const vec3 plane_point = {0.f, 0.f, 0.f};
+  const vec3 plane_normal = {-1.f, 0.f, 0.f};
+  vec3 output[4];
+  int output_length = geometry::clip_polygon<3>(output, plane_point, plane_normal, &points[0]);
+
+  if (output_length >= 3) {
+    parameter.append<ta_global_parameter::polygon_type_0>() =
+      ta_global_parameter::polygon_type_0(parameter_control_word,
+					  isp_tsp_instruction_word,
+					  tsp_instruction_word,
+					  0, // texture_control_word
+					  0, // data_size_for_sort_dma
+					  0  // next_address_for_sort_dma
+					  );
+    transform1(parameter, output[0], colors[0], false);
+    transform1(parameter, output[1], colors[1], false);
+    transform1(parameter, output[2], colors[2], true);
+  }
+  if (output_length >= 4) {
+    parameter.append<ta_global_parameter::polygon_type_0>() =
+      ta_global_parameter::polygon_type_0(parameter_control_word,
+					  isp_tsp_instruction_word,
+					  tsp_instruction_word,
+					  0, // texture_control_word
+					  0, // data_size_for_sort_dma
+					  0  // next_address_for_sort_dma
+					  );
+    transform1(parameter, output[0], colors[0], false);
+    transform1(parameter, output[2], colors[2], false);
+    transform1(parameter, output[3], colors[3], true);
+  }
+
+  /*
+
+    A B
+    D C
+
+   */
+}
+
+void init_texture_memory(const struct opb_size& opb_size)
+{
+  auto mem = reinterpret_cast<volatile texture_memory_alloc *>(texture_memory32);
+
+  background_parameter(mem->background, 0xff220000);
+
+  region_array2(mem->region_array,
+	        (offsetof (struct texture_memory_alloc, object_list)),
+		640 / 32, // width
+		480 / 32, // height
+		opb_size
+		);
+}
+
+uint32_t _ta_parameter_buf[((32 * 8192) + 32) / 4];
+
+void main()
+{
+  uint32_t * command_buf = align_32byte(_command_buf);
+  uint32_t * receive_buf = align_32byte(_receive_buf);
+
+  vga();
+
+  // The address of `ta_parameter_buf` must be a multiple of 32 bytes.
+  // This is mandatory for ch2-dma to the ta fifo polygon converter.
+  uint32_t * ta_parameter_buf = align_32byte(_ta_parameter_buf);
+
+  constexpr uint32_t ta_alloc = ta_alloc_ctrl::pt_opb::no_list
+			      | ta_alloc_ctrl::tm_opb::no_list
+			      | ta_alloc_ctrl::t_opb::no_list
+			      | ta_alloc_ctrl::om_opb::no_list
+                              | ta_alloc_ctrl::o_opb::_16x4byte;
+
+  constexpr struct opb_size opb_size = { .opaque = 16 * 4
+				       , .opaque_modifier = 0
+				       , .translucent = 0
+				       , .translucent_modifier = 0
+				       , .punch_through = 0
+				       };
+
+  holly.SOFTRESET = softreset::pipeline_soft_reset
+		  | softreset::ta_soft_reset;
+  holly.SOFTRESET = 0;
+
+  core_init();
+  init_texture_memory(opb_size);
+
+  uint32_t frame_ix = 0;
+  constexpr uint32_t num_frames = 1;
+  float theta = 0;
+  float x_pos = 0;
+  float y_pos = 0;
+
+  while (1) {
+    do_get_condition(command_buf, receive_buf);
+
+    ta_polygon_converter_init(opb_size.total(),
+			      ta_alloc,
+			      640 / 32,
+			      480 / 32);
+
+    const float l_ = static_cast<float>(data[0].analog_axis_1) * (1.f / 255.f);
+    const float r_ = static_cast<float>(data[0].analog_axis_2) * (1.f / 255.f);
+    const float t_ = ((l_ > r_) ? l_ : -r_) * 3.14f / 2.f;
+
+    if (t_ > theta) theta += (0.04f * ((t_ - theta) * (t_ - theta)));
+    else            theta -= (0.04f * ((t_ - theta) * (t_ - theta)));
+
+    const float x_ = static_cast<float>(data[0].analog_axis_3 - 0x80) / 127.f;
+    const float y_ = static_cast<float>(data[0].analog_axis_4 - 0x80) / 127.f;
+    if (x_ > x_pos) x_pos += (0.02f * ((x_ - x_pos) * (x_ - x_pos)));
+    else            x_pos -= (0.02f * ((x_ - x_pos) * (x_ - x_pos)));
+    if (y_ > y_pos) y_pos += (0.02f * ((y_ - y_pos) * (y_ - y_pos)));
+    else            y_pos -= (0.02f * ((y_ - y_pos) * (y_ - y_pos)));
+
+    auto parameter = ta_parameter_writer(ta_parameter_buf);
+    for (uint32_t i = 0; i < circle::num_faces; i++) {
+      transform(parameter,
+		circle::vertices,
+		circle::faces[i],
+		{1.0f, 1.0f, 0.0f, 0.0f}, // color
+		{x_pos * 2, y_pos * 2, 0.0f}, // position
+		theta,
+		true // clipping
+		);
+    }
+
+    parameter.append<ta_global_parameter::end_of_list>() = ta_global_parameter::end_of_list(para_control::para_type::end_of_list);
+    ta_polygon_converter_transfer(ta_parameter_buf, parameter.offset);
+    ta_wait_opaque_list();
+    core_start_render(frame_ix, num_frames);
+
+    v_sync_in();
+    core_wait_end_of_render_video(frame_ix, num_frames);
+    frame_ix += 1;
+  }
+}

example/example.mk

@@ -211,6 +211,20 @@ CLIPPING_OBJ = \
 example/clipping.elf: LDSCRIPT = $(LIB)/alt.lds
 example/clipping.elf: $(START_OBJ) $(CLIPPING_OBJ)
 
+CLIPPING2_OBJ = \
+	example/clipping2.o \
+	vga.o \
+	holly/core.o \
+	holly/region_array.o \
+	holly/background.o \
+	holly/ta_fifo_polygon_converter.o \
+	maple/maple.o \
+	sh7091/serial.o \
+	$(LIBGCC)
+
+example/clipping2.elf: LDSCRIPT = $(LIB)/alt.lds
+example/clipping2.elf: $(START_OBJ) $(CLIPPING2_OBJ)
+
 MAPLE_DEVICE_REQUEST_OBJ = \
 	example/maple_device_request.o \
 	vga.o \

geometry/triangle.hpp

@@ -0,0 +1,28 @@
+#pragma once
+
+#include "geometry.hpp"
+
+namespace triangle {
+  constexpr vec3 vertices[] = {
+    { -1.000000f,  0.000000f,  0.000000f },
+    {  1.000000f,  0.000000f,  1.000000f },
+    {  1.000000f,  0.000000f, -1.000000f },
+  };
+
+  constexpr vec2 texture[] = {
+    {  0.000000f,  0.000000f },
+    {  1.000000f,  0.000000f },
+    {  1.000000f,  1.000000f },
+  };
+
+  constexpr vec3 normals[] = {
+    { -0.000000f,  1.000000f, -0.000000f },
+  };
+
+  constexpr face_vtn faces[] = {
+    {{0, 0, 0}, {1, 1, 0}, {2, 2, 0}},
+  };
+
+  constexpr uint32_t num_faces = (sizeof (faces)) / (sizeof (face_vtn));
+
+}

geometry/triangle.obj

@@ -0,0 +1,12 @@
+# Blender 3.3.6
+# www.blender.org
+o Triangle
+v -1.000000 0.000000 0.000000
+v 1.000000 0.000000 1.000000
+v 1.000000 0.000000 -1.000000
+vn -0.0000 1.0000 -0.0000
+vt 0.000000 0.000000
+vt 1.000000 0.000000
+vt 1.000000 1.000000
+s 0
+f 1/1/1 2/2/1 3/3/1

math/geometry.hpp

@@ -0,0 +1,119 @@
+#include <functional>
+
+#include "vec.hpp"
+
+namespace geometry {
+
+template <int L, typename T>
+vec<L, T> line_plane_intersection(const vec<L, T>& plane_point,  // p0
+				  const vec<L, T>& plane_normal, // n
+				  const vec<L, T>& line_start,   // l0
+				  const vec<L, T>& line_end
+				  )
+{
+  const auto line_vector = line_end - line_start; // l
+
+  const T intersection = // d
+      dot(plane_point - line_start, plane_normal)
+    / dot(line_vector, plane_normal);
+
+  return line_start + line_vector * intersection;
+}
+
+template <int L, typename T>
+T clip_boundary(const vec<L, T>& plane_point,  // X
+		const vec<L, T>& plane_normal, // Nc
+		const vec<L, T>& line_point
+		)
+{
+  return dot(plane_normal, line_point - plane_point);
+}
+
+template <typename T>
+inline T positive_modulo(T a, T b)
+{
+  return (a % b + b) % b;
+}
+
+template <int polygon_len, int L, typename T>
+inline int clip_polygon1(vec<L, T> * output,
+			 const vec<L, T> plane_point,
+			 const vec<L, T> plane_normal,
+			 const vec<L, T> * polygon,
+			 const int ix_s,
+			 const int ix_f,
+			 const bool last_inside)
+{
+  const vec<L, T>& s = polygon[ix_s];
+  const vec<L, T>& f = polygon[ix_f];
+
+  bool this_inside = 0.f < clip_boundary<L, T>(plane_point,
+					       plane_normal,
+					       f);
+
+  int length = 0;
+  switch ((last_inside << 1) | (this_inside << 0)) {
+  case 0b00: // no output
+    length = 0;
+    break;
+  case 0b01: // I, F
+    length = 2;
+    {
+      auto i = line_plane_intersection<L, T>(plane_point, plane_normal, s, f);
+      *output++ = i;
+      *output++ = f;
+    }
+    break;
+  case 0b10: // I
+    length = 1;
+    {
+      auto i = line_plane_intersection<L, T>(plane_point, plane_normal, s, f);
+      *output++ = i;
+    }
+    break;
+  case 0b11: // F
+    length = 1;
+    *output++ = f;
+    break;
+  }
+
+  bool end_of_polygon = ix_f == (polygon_len - 1);
+  if (!end_of_polygon) {
+    return length +
+      clip_polygon1<polygon_len, L, T>(output,
+				       plane_point,
+				       plane_normal,
+				       polygon,
+				       ix_f,
+				       ix_f + 1,
+				       this_inside);
+  } else {
+    return length;
+  }
+}
+
+template <int polygon_len, int L, typename T>
+int clip_polygon(vec<L, T> * output,
+		 const vec<L, T>& plane_point,
+		 const vec<L, T>& plane_normal,
+		 const vec<L, T> * polygon
+		 )
+{
+  const vec<L, T> f = polygon[polygon_len - 1];
+
+  // It would be nice to remove the extra dot product, but the
+  // alternative seems likely uglier.
+  bool this_inside = 0.f < clip_boundary<L, T>(plane_point,
+					       plane_normal,
+					       f);
+
+  return clip_polygon1<polygon_len, L, T>(output,
+					  plane_point,
+					  plane_normal,
+					  polygon,
+					  polygon_len - 1, // ix_s
+					  0,               // ix_f
+					  this_inside);
+}
+
+}

sh7091/serial.cpp

@@ -48,7 +48,7 @@ void string(const char * s)
 }
 
 template <typename T>
-void integer(const T n)
+void integer(const T n, const char end)
 {
   constexpr uint32_t length = (sizeof (T)) * 2;
   char num_buf[length + 1];
@@ -56,11 +56,21 @@ void integer(const T n)
   num_buf[length] = 0;
   string("0x");
   string(num_buf);
-  string("\n");
+  character(end);
+}
+
+template <typename T>
+void integer(const T n)
+{
+  return integer(n, '\n');
 }
 
 template void integer<uint32_t>(uint32_t param);
 template void integer<uint16_t>(uint16_t param);
 template void integer<uint8_t>(uint8_t param);
 
+template void integer<uint32_t>(uint32_t param, char end);
+template void integer<uint16_t>(uint16_t param, char end);
+template void integer<uint8_t>(uint8_t param, char end);
+
 }

sh7091/serial.hpp

@@ -6,6 +6,9 @@ void character(const char c);
 
 void string(const char * s);
 
+template <typename T>
+void integer(const T n, const char end);
+
 template <typename T>
 void integer(const T n);