From 6f3ffefef60bae19408a01fbf8182afe137b4921 Mon Sep 17 00:00:00 2001
From: Lucas Fryzek <lucas.fryzek@fryzekconcepts.com>
Date: Thu, 8 Aug 2024 08:37:39 +0100
Subject: drv: Document PixelShader address encoding in PDS

---
 src/drv.c | 9 +++++++++
 1 file changed, 9 insertions(+)

(limited to 'src/drv.c')

diff --git a/src/drv.c b/src/drv.c
index e3252af..8a446ee 100644
--- a/src/drv.c
+++ b/src/drv.c
@@ -474,6 +474,15 @@ static void register_hw_render_ctx(struct driver_state *state) {
 
 void patch_memory(struct driver_state *state) {
     /* Patch PDS Pixel Code Data 0 buffer */
+    /* I think Pixel Shader address is encoded like so
+     * ((num & 0xf0) << 4)     |
+     * ((num & 0xf00) << 4)    |
+     * ((num & 0x7000) << 4)   |
+     * ((num & 0x78000) >> 11) |
+     * ((num & 0x80000) >> 19)
+     * This was determined by experimentation to see where each bit ends up
+     * in the PDS buffer after modifying the address returned by the driver
+     */
     //pds_pcd[0] = ;
 
     uint32_t modified_pds_addr =
-- 
cgit