From eb98f2fb88c72cad13d1ee8a0a4521ef8330a1d0 Mon Sep 17 00:00:00 2001
From: lightningterror <lightningterror@yahoo.com>
Date: Fri, 19 Jul 2019 18:06:40 +0200
Subject: [PATCH] gsdx-hw: Add OI rendering fix for Big Mutha Truckers.

It will allow to render the shadows properly, also update the crc
hack to skip less effects.
---
 plugins/GSdx/Renderers/HW/GSHwHack.cpp     | 18 ++++++------
 plugins/GSdx/Renderers/HW/GSRendererHW.cpp | 33 ++++++++++++++++++++++
 plugins/GSdx/Renderers/HW/GSRendererHW.h   |  1 +
 3 files changed, 42 insertions(+), 10 deletions(-)

diff --git a/plugins/GSdx/Renderers/HW/GSHwHack.cpp b/plugins/GSdx/Renderers/HW/GSHwHack.cpp
index 7351fa699a4eb..78adbb15f60bb 100644
--- a/plugins/GSdx/Renderers/HW/GSHwHack.cpp
+++ b/plugins/GSdx/Renderers/HW/GSHwHack.cpp
@@ -42,16 +42,14 @@ bool GSC_BigMuthaTruckers(const GSFrameInfo& fi, int& skip)
 {
 	if(skip == 0)
 	{
-		if(fi.TME && (fi.FBP == 0x00000 || fi.FBP == 0x00a00) && fi.FPSM == fi.TPSM && fi.TPSM == PSM_PSMCT16)
-		{
-			// A real mess.
-			// Half screen bottom and vertical stripes issues.
-			//
-			// HDR colclip/conclip not supported,
-			// Depth target lookup,
-			// Texture shuffle and SW emulated fbmask.
-			// https://github.com/PCSX2/pcsx2/issues/2449
-			skip = 3;
+		if(fi.TME && (fi.TBP0 == 0x01400 || fi.TBP0 == 0x012c0) && fi.FPSM == fi.TPSM && fi.TPSM == PSM_PSMCT16)
+		{
+			// Mid-texture pointer is a cache miss,
+			// luckily we replace a half-screen TS effect with a full-screen one in 
+			// EmulateTextureShuffleAndFbmask (see #2934).
+			// While this works for the time being, it's not ideal.
+			// Skip the unneeded extra TS draw.
+			skip = 1;
 		}
 	}
 
diff --git a/plugins/GSdx/Renderers/HW/GSRendererHW.cpp b/plugins/GSdx/Renderers/HW/GSRendererHW.cpp
index a25d0ad3de188..2832e90ed2b5a 100644
--- a/plugins/GSdx/Renderers/HW/GSRendererHW.cpp
+++ b/plugins/GSdx/Renderers/HW/GSRendererHW.cpp
@@ -1464,6 +1464,7 @@ GSRendererHW::Hacks::Hacks()
 	, m_oo(NULL)
 	, m_cu(NULL)
 {
+	m_oi_list.push_back(HackEntry<OI_Ptr>(CRC::BigMuthaTruckers, CRC::RegionCount, &GSRendererHW::OI_BigMuthaTruckers));
 	m_oi_list.push_back(HackEntry<OI_Ptr>(CRC::FFXII, CRC::EU, &GSRendererHW::OI_FFXII));
 	m_oi_list.push_back(HackEntry<OI_Ptr>(CRC::FFX, CRC::RegionCount, &GSRendererHW::OI_FFX));
 	m_oi_list.push_back(HackEntry<OI_Ptr>(CRC::MetalSlug6, CRC::RegionCount, &GSRendererHW::OI_MetalSlug6));
@@ -1689,6 +1690,38 @@ bool GSRendererHW::OI_BlitFMV(GSTextureCache::Target* _rt, GSTextureCache::Sourc
 
 // OI (others input?/implementation?) hacks replace current draw call
 
+bool GSRendererHW::OI_BigMuthaTruckers(GSTexture* rt, GSTexture* ds, GSTextureCache::Source* t)
+{
+	// Rendering pattern:
+	// CRTC frontbuffer at 0x0 is interlaced (half vertical resolution),
+	// game needs to do a depth effect (so green channel to alpha),
+	// but there is a vram limitation so green is pushed into the alpha channel of the CRCT buffer,
+	// vertical resolution is half so only half is processed at once
+	// We, however, don't have this limitation so we'll replace the draw with a full-screen TS.
+
+	GIFRegTEX0 Texture = m_context->TEX0;
+
+	GIFRegTEX0 Frame;
+	Frame.TBW = m_context->FRAME.FBW;
+	Frame.TBP0 = m_context->FRAME.FBP;
+	Frame.TBP0 = m_context->FRAME.Block();
+
+	if (PRIM->TME && Frame.TBW == 10 && Texture.TBW == 10 && Frame.TBP0 == 0x00a00 && Texture.PSM == PSM_PSMT8H && (m_r.y == 256 || m_r.y == 224))
+	{
+		// 224 ntsc, 256 pal.
+		GL_INS("OI_BigMuthaTruckers half bottom offset");
+
+		size_t count = m_vertex.next;
+		GSVertex* v = &m_vertex.buff[0];
+		const uint16 offset = (uint16)m_r.y * 16;
+
+		for (size_t i = 0; i < count; i++)
+			v[i].V += offset;
+	}
+
+	return true;
+}
+
 bool GSRendererHW::OI_FFXII(GSTexture* rt, GSTexture* ds, GSTextureCache::Source* t)
 {
 	static uint32* video = NULL;
diff --git a/plugins/GSdx/Renderers/HW/GSRendererHW.h b/plugins/GSdx/Renderers/HW/GSRendererHW.h
index f6d7720564e18..e9bbbbacf2f33 100644
--- a/plugins/GSdx/Renderers/HW/GSRendererHW.h
+++ b/plugins/GSdx/Renderers/HW/GSRendererHW.h
@@ -52,6 +52,7 @@ class GSRendererHW : public GSRenderer
 	void OI_GsMemClear(); // always on
 	void OI_DoubleHalfClear(GSTexture* rt, GSTexture* ds); // always on
 
+	bool OI_BigMuthaTruckers(GSTexture* rt, GSTexture* ds, GSTextureCache::Source* t);
 	bool OI_FFXII(GSTexture* rt, GSTexture* ds, GSTextureCache::Source* t);
 	bool OI_FFX(GSTexture* rt, GSTexture* ds, GSTextureCache::Source* t);
 	bool OI_MetalSlug6(GSTexture* rt, GSTexture* ds, GSTextureCache::Source* t);