spinning triangle

bits.h

@@ -178,7 +178,7 @@
 #define VTX_XY__y_coordinate(v) (((v) & 0xffff) << 16)
 #define VTX_XY__x_coordinate(v) (((v) & 0xffff) << 0)
 #define VTX_XZ__z_coordinate(v) (((v) & 0xffff) << 16)
-#define VTX_XZ__z_coordinate(v) (((v) & 0xffff) << 0)
+#define VTX_XZ__x_coordinate(v) (((v) & 0xffff) << 0)
 #define VTX_YZ__z_coordinate(v) (((v) & 0xffff) << 16)
 #define VTX_YZ__y_coordinate(v) (((v) & 0xffff) << 0)
 #define VTX_DIFF__z_coordinate(v) (((v) & 0x3ff) << 20)
@@ -307,17 +307,17 @@
 #define GXSTAT__command_fifo_interrupt_condition__disable (0x0 << 30)
 #define GXSTAT__command_fifo_interrupt_condition__half_full (0x1 << 30)
 #define GXSTAT__command_fifo_interrupt_condition__empty (0x2 << 30)
-#define GXSTAT__geometry_engine_busy(v) (((v) >> 27) & 0x1)
+#define GXSTAT__geometry_engine_busy (0x1 << 27)
-#define GXSTAT__fifo_status__empty(v) (((v) >> 26) & 0x1)
+#define GXSTAT__fifo_status__empty (0x1 << 26)
-#define GXSTAT__fifo_status__less_than_half_full(v) (((v) >> 25) & 0x1)
+#define GXSTAT__fifo_status__less_than_half_full (0x1 << 25)
-#define GXSTAT__fifo_status__full(v) (((v) >> 24) & 0x1)
+#define GXSTAT__fifo_status__full (0x1 << 24)
 #define GXSTAT__command_fifo_count(v) (((v) >> 16) & 0xff)
-#define GXSTAT__matrix_stack_status__stack_overflow_or_underflow(v) (((v) >> 15) & 0x1)
+#define GXSTAT__matrix_stack_status__overflow_or_underflow (0x1 << 15)
-#define GXSTAT__matrix_stack_status__stack_busy(v) (((v) >> 14) & 0x1)
+#define GXSTAT__matrix_stack_status__busy (0x1 << 14)
-#define GXSTAT__matrix_stack_status__projection_matrix_stack_level(v) (((v) >> 13) & 0x1)
+#define GXSTAT__matrix_stack_status__projection_stack_level(v) (((v) >> 13) & 0x1)
-#define GXSTAT__matrix_stack_status__position_and_vector_matrix_stack_level(v) (((v) >> 8) & 0x1f)
+#define GXSTAT__matrix_stack_status__position_and_vector_stack_level(v) (((v) >> 8) & 0x1f)
-#define GXSTAT__test_status(v) (((v) >> 1) & 0x1)
+#define GXSTAT__test_status (0x1 << 1)
-#define GXSTAT__test_busy(v) (((v) >> 0) & 0x1)
+#define GXSTAT__test_busy (0x1 << 0)
 #define LISTRAM_COUNT__counter(v) (((v) >> 0) & 0xfff)
 #define VTXRAM_COUNT__counter(v) (((v) >> 0) & 0x1fff)
 #define OBJ_ATTRIBUTE_0__obj_shape__square (0x0 << 14)

main.c

@@ -398,12 +398,21 @@ void main()
   // 2d graphics engine B OBJ
   io_registers.a.VRAM_HI_CNT = (1 << 15) | (0b10 << 8);
 
+  io_registers.a.POWCNT = 0
+    | POWCNT__lcd_output_destination__a_to_upper__b_to_lower
+    | POWCNT__2d_graphics_engine_b__enable
+    | POWCNT__geometry_engine__enable
+    | POWCNT__rendering_engine__enable
+    | POWCNT__2d_graphics_engine_a__enable
+    | POWCNT__lcd__enable;
+
   io_registers.a.DISPCNT = 0
     | DISPCNT__bg_screen_base_offset(0)
     | DISPCNT__bg_character_base_offset(0)
     | DISPCNT__display_mode__graphics_display
     | DISPCNT__bg0__enable
-    | DISPCNT__display_selection_for_bg0__2d_graphics
+    //| DISPCNT__display_selection_for_bg0__2d_graphics
+    | DISPCNT__display_selection_for_bg0__3d_graphics
     | DISPCNT__bg_mode__text0_text1_text2_text3
     ;
 
@@ -533,6 +542,70 @@ void main()
     (1/β)cosθ
   */
 
+  /* do 3d */
+  while (io_registers.a.GXSTAT & GXSTAT__geometry_engine_busy);
+
+  // clear matrix stack status
+  io_registers.a.GXSTAT |= GXSTAT__matrix_stack_status__overflow_or_underflow;
+
+  // clear projection matrix stack
+  int projection_stack_level = GXSTAT__matrix_stack_status__projection_stack_level(io_registers.a.GXSTAT);
+  if (projection_stack_level) {
+    io_registers.a.MTX_MODE = MTX_MODE__matrix_mode__projection;
+    io_registers.a.MTX_POP = MTX_POP__number_of_pops(1);
+  }
+
+  // clear position_and_vector matrix stack
+  int position_and_vector_stack_level = GXSTAT__matrix_stack_status__position_and_vector_stack_level(io_registers.a.GXSTAT);
+  if (position_and_vector_stack_level) {
+    io_registers.a.MTX_MODE = MTX_MODE__matrix_mode__position_and_vector;
+    io_registers.a.MTX_POP = MTX_POP__number_of_pops(position_and_vector_stack_level);
+  }
+
+  // load identity matrices
+  io_registers.a.MTX_MODE = MTX_MODE__matrix_mode__projection;
+  io_registers.a.MTX_IDENTITY = 0;
+  io_registers.a.MTX_SCALE = (1 << 12);
+  io_registers.a.MTX_SCALE = (1 << 12);
+  io_registers.a.MTX_SCALE = (1 << 12);
+
+  io_registers.a.MTX_MODE = MTX_MODE__matrix_mode__position;
+  io_registers.a.MTX_IDENTITY = 0;
+
+  io_registers.a.MTX_MODE = MTX_MODE__matrix_mode__position_and_vector;
+  io_registers.a.MTX_IDENTITY = 0;
+
+  io_registers.a.SWAP_BUFFERS = 0
+    | SWAP_BUFFERS__depth_buffering__z_value
+    | SWAP_BUFFERS__translucent_polygon_y_sorting__auto_sort;
+
+  io_registers.a.DISP3DCNT = 0
+    | DISP3DCNT__clear_image__disable
+    | DISP3DCNT__fog_master__disable
+    | DISP3DCNT__edge_marking__disable
+    | DISP3DCNT__anti_aliasing__disable
+    | DISP3DCNT__alpha_blending__disable
+    | DISP3DCNT__alpha_test__disable
+    | DISP3DCNT__texture_mapping__disable;
+
+  io_registers.a.CLEAR_COLOR = 0
+    | CLEAR_COLOR__clear_polygon_id(31)
+    | CLEAR_COLOR__alpha_value(31)
+    | CLEAR_COLOR__red(10);
+
+  io_registers.a.CLEAR_DEPTH = CLEAR_DEPTH__value(0x7fff);
+
+  io_registers.a.POLYGON_ATTR = 0
+    | POLYGON_ATTR__alpha_value(31)
+    | POLYGON_ATTR__render_front_surface__enable
+    | POLYGON_ATTR__render_back_surface__enable;
+
+  io_registers.a.VIEWPORT = 0
+    | VIEWPORT__y2(191)
+    | VIEWPORT__x2(255)
+    | VIEWPORT__y1(0)
+    | VIEWPORT__x1(0);
+
   int theta = 0;
   while (1) {
     struct sign_v cos = cos_table[theta];
@@ -540,6 +613,58 @@ void main()
     if (sin_theta >= 360) sin_theta -= 360;
     struct sign_v sin = cos_table[sin_theta];
 
+    int _cos = cos.sign ? -cos.v : cos.v;
+    int _sin = sin.sign ? -sin.v : sin.v;
+
+    {
+      int x = -222;
+      int y = -128;
+      int x1 = x * _cos + y * _sin;
+      int y1 = -x * _sin + y * _cos;
+
+      io_registers.a.BEGIN_VTXS = BEGIN_VTXS__type__triangle;
+      io_registers.a.COLOR = (31 << 10); // blue
+      io_registers.a.VTX_10 = 0
+        | VTX_10__z_coordinate(1 << 6)
+        | VTX_10__y_coordinate(y1 >> (3 + 8))
+        | VTX_10__x_coordinate(x1 >> (3 + 8))
+        ;
+    }
+
+    {
+      int x = 222;
+      int y = -128;
+      int x1 = x * _cos + y * _sin;
+      int y1 = -x * _sin + y * _cos;
+
+      io_registers.a.COLOR = (31 << 5); // green
+      io_registers.a.VTX_10 = 0
+        | VTX_10__z_coordinate(1 << 6)
+        | VTX_10__y_coordinate(y1 >> (3 + 8))
+        | VTX_10__x_coordinate(x1 >> (3 + 8))
+        ;
+    }
+
+    {
+      int x = 0 << 8;
+      int y = 1 << 8;
+      int x1 = x * _cos + y * _sin;
+      int y1 = -x * _sin + y * _cos;
+
+      io_registers.a.COLOR = (31 << 0); // blue
+      io_registers.a.VTX_10 = 0
+        | VTX_10__z_coordinate(1 << 6)
+        | VTX_10__y_coordinate(y1 >> (3 + 8))
+        | VTX_10__x_coordinate(x1 >> (3 + 8))
+        ;
+    }
+
+    io_registers.a.END_VTXS = 0;
+
+    io_registers.a.SWAP_BUFFERS = 0
+      | SWAP_BUFFERS__depth_buffering__z_value
+      | SWAP_BUFFERS__translucent_polygon_y_sorting__auto_sort;
+
     // dx
     oam.b.param[0].pa = cos.sign ? cos.v : -cos.v;
 

registers/graphics_engine_bits.csv

@@ -202,7 +202,7 @@
 "VTX_XY",,"15-0","x_coordinate",,"0xffff",
 ,,,,,,
 "VTX_XZ",,"31-16","z_coordinate",,"0xffff",
-"VTX_XZ",,"15-0","z_coordinate",,"0xffff",
+"VTX_XZ",,"15-0","x_coordinate",,"0xffff",
 ,,,,,,
 "VTX_YZ",,"31-16","z_coordinate",,"0xffff",
 "VTX_YZ",,"15-0","y_coordinate",,"0xffff",
@@ -348,17 +348,17 @@
 "GXSTAT","command_fifo_interrupt_condition","31-30","disable","0b00",,
 "GXSTAT","command_fifo_interrupt_condition","31-30","half_full","0b01",,
 "GXSTAT","command_fifo_interrupt_condition","31-30","empty","0b10",,
-"GXSTAT",,27,"geometry_engine_busy",,,
+"GXSTAT",,27,"geometry_engine_busy",1,,
-"GXSTAT","fifo_status",26,"empty",,,
+"GXSTAT","fifo_status",26,"empty",1,,
-"GXSTAT","fifo_status",25,"less_than_half_full",,,
+"GXSTAT","fifo_status",25,"less_than_half_full",1,,
-"GXSTAT","fifo_status",24,"full",,,
+"GXSTAT","fifo_status",24,"full",1,,
 "GXSTAT",,"23-16","command_fifo_count",,,
-"GXSTAT","matrix_stack_status",15,"stack_overflow_or_underflow",,,
+"GXSTAT","matrix_stack_status",15,"overflow_or_underflow",1,,
-"GXSTAT","matrix_stack_status",14,"stack_busy",,,
+"GXSTAT","matrix_stack_status",14,"busy",1,,
-"GXSTAT","matrix_stack_status",13,"projection_matrix_stack_level",,,
+"GXSTAT","matrix_stack_status",13,"projection_stack_level",,,
-"GXSTAT","matrix_stack_status","12-8","position_and_vector_matrix_stack_level",,,
+"GXSTAT","matrix_stack_status","12-8","position_and_vector_stack_level",,,
-"GXSTAT",,1,"test_status",,,
+"GXSTAT",,1,"test_status",1,,
-"GXSTAT",,0,"test_busy",,,
+"GXSTAT",,0,"test_busy",1,,
 ,,,,,,
 "LISTRAM_COUNT",,"11-0","counter",,,
 ,,,,,,