From 58411243d1417a82f45e4f9440d4bc4b8f8297f6 Mon Sep 17 00:00:00 2001
From: Jannik Vogel <email@jannikvogel.de>
Date: Fri, 17 Jul 2015 00:16:52 +0200
Subject: [PATCH] Fix delta-R6G5B5 code (incl. new mapping algorithm)
---
hw/xbox/nv2a.c | 20 +++++++-------------
1 file changed, 7 insertions(+), 13 deletions(-)
diff --git a/hw/xbox/nv2a.c b/hw/xbox/nv2a.c
index 407822508b..8c6d7df703 100644
--- a/hw/xbox/nv2a.c
+++ b/hw/xbox/nv2a.c
@@ -2097,21 +2097,15 @@ static uint8_t* convert_texture_data(const TextureShape s,
int x, y;
for (y = 0; y < height; y++) {
for (x = 0; x < width; x++) {
- uint8_t v;
- uint16_t rgb565 = *(uint16_t*)(data + y * pitch + x * 2);
+ uint16_t rgb655 = *(uint16_t*)(data + y * pitch + x * 2);
int8_t *pixel = &converted_data[(y * width + x) * 3];
- /* FIXME: This is pretty ugly code to extend from
- * signed 565 to signed 888 (hopefully)
+ /* Maps 5 bit G and B signed value range to 8 bit
+ * signed values. R is probably unsigned.
*/
- v = (rgb565 & 0xF800) >> 8;
- pixel[0] = (v & 0x80) ? *(int8_t*)&v * 16 / 0x80
- : ((v & 0x78) * 15) / 0x78;
- v = (rgb565 & 0x07E0) >> 3;
- pixel[1] = (v & 0x80) ? *(int8_t*)&v * 32 / 0x80
- : ((v & 0x7C) * 31) / 0x7C;
- v = (rgb565 & 0x001F) << 3;
- pixel[2] = (v & 0x80) ? *(int8_t*)&v * 16 / 0x80
- : ((v & 0x78) * 15) / 0x78;
+ rgb655 ^= (1 << 9) | (1 << 4);
+ pixel[0] = ((rgb655 & 0xFC00) >> 10) * 0x7F / 0x3F;
+ pixel[1] = ((rgb655 & 0x03E0) >> 5) * 0xFF / 0x1F - 0x80;
+ pixel[2] = (rgb655 & 0x001F) * 0xFF / 0x1F - 0x80;
}
}
return converted_data;