rtl/gfx: implement perspective correction

3 files changed, 123 insertions, 4 deletions

diff --git a/rtl/gfx/gfx.sv b/rtl/gfx/gfx.sv
index 2398826..6bead44 100644
--- a/rtl/gfx/gfx.sv
+++ b/rtl/gfx/gfx.sv
@@ -62,6 +62,24 @@ module gfx
 		.*
 	);
 
+	logic persp_ready, persp_valid;
+	raster_xyzw persp_vertex_a, persp_vertex_b, persp_vertex_c;
+
+	gfx_persp perspective
+	(
+		.in_ready(persp_ready),
+		.in_valid(0), //TODO
+		.out_ready(raster_ready),
+		.out_valid(persp_valid),
+		.in_vertex_a(), //TODO
+		.in_vertex_b(), //TODO
+		.in_vertex_c(), //TODO
+		.out_vertex_a(persp_vertex_a),
+		.out_vertex_b(persp_vertex_b),
+		.out_vertex_c(persp_vertex_c),
+		.*
+	);
+
 	logic raster_ready;
 	fixed_tri raster_ws;
 	bary_lanes barys;
@@ -72,13 +90,13 @@ module gfx
 	(
 		.ws(raster_ws),
 		.in_ready(raster_ready),
-		.in_valid(0), //TODO
+		.in_valid(persp_valid),
 		.out_ready(funnel_ready),
 		.out_valid(raster_valid),
 
-		.vertex_a(), //TODO
-		.vertex_b(), //TODO
-		.vertex_c(), //TODO
+		.vertex_a(persp_vertex_a),
+		.vertex_b(persp_vertex_b),
+		.vertex_c(persp_vertex_c),
 
 		.*
 	);
diff --git a/rtl/gfx/gfx_persp.sv b/rtl/gfx/gfx_persp.sv
new file mode 100644
index 0000000..0a75d39
--- /dev/null
+++ b/rtl/gfx/gfx_persp.sv
@@ -0,0 +1,49 @@
+`include "gfx/gfx_defs.sv"
+
+module gfx_persp
+(
+	input  logic       clk,
+	                   rst_n,
+
+	input  raster_xyzw in_vertex_a,
+	                   in_vertex_b,
+	                   in_vertex_c,
+	input  logic       in_valid,
+	output logic       in_ready,
+
+	input  logic       out_ready,
+	output logic       out_valid,
+	output raster_xyzw out_vertex_a,
+	                   out_vertex_b,
+	                   out_vertex_c
+);
+
+	logic stall;
+
+	gfx_pipeline_flow #(.STAGES(`FIXED_DIV_STAGES)) flow
+	(
+		.*
+	);
+
+	gfx_persp_vertex persp_a
+	(
+		.in_vertex(in_vertex_a),
+		.out_vertex(out_vertex_a),
+		.*
+	);
+
+	gfx_persp_vertex persp_b
+	(
+		.in_vertex(in_vertex_b),
+		.out_vertex(out_vertex_b),
+		.*
+	);
+
+	gfx_persp_vertex persp_c
+	(
+		.in_vertex(in_vertex_c),
+		.out_vertex(out_vertex_c),
+		.*
+	);
+
+endmodule
diff --git a/rtl/gfx/gfx_persp_vertex.sv b/rtl/gfx/gfx_persp_vertex.sv
new file mode 100644
index 0000000..f7434f0
--- /dev/null
+++ b/rtl/gfx/gfx_persp_vertex.sv
@@ -0,0 +1,52 @@
+`include "gfx/gfx_defs.sv"
+
+module gfx_persp_vertex
+(
+	input  logic       clk,
+
+	input  raster_xyzw in_vertex,
+	input  logic       stall,
+
+	output raster_xyzw out_vertex
+);
+
+	raster_xyzw skid_vertex;
+
+	gfx_fixed_div x_div
+	(
+		.z(in_vertex.xy.x),
+		.d(in_vertex.zw.w),
+		.q(skid_vertex.xy.x),
+		.*
+	);
+
+	gfx_fixed_div y_div
+	(
+		.z(in_vertex.xy.y),
+		.d(in_vertex.zw.w),
+		.q(skid_vertex.xy.y),
+		.*
+	);
+
+	gfx_pipes #(.WIDTH($bits(fixed)), .DEPTH(`FIXED_DIV_STAGES)) z_pipes
+	(
+		.in(in_vertex.zw.z),
+		.out(skid_vertex.zw.z),
+		.*
+	);
+
+	gfx_pipes #(.WIDTH($bits(fixed)), .DEPTH(`FIXED_DIV_STAGES)) w_pipes
+	(
+		.in(in_vertex.zw.w),
+		.out(skid_vertex.zw.w),
+		.*
+	);
+
+	gfx_skid_buf #(.WIDTH($bits(out_vertex))) vertex_skid
+	(
+		.in(skid_vertex),
+		.out(out_vertex),
+		.*
+	);
+
+endmodule