GS: Do scissor test in autoflush handler.

The autoflush handler is called before the scissor test in the vertex kick.
To save some work and prevent unnecessary autoflushes, do the scissor test
in the autoflush handler also.

Author: TJnotJT

pcsx2/GS/GSState.cpp

@@ -4041,10 +4041,13 @@ __forceinline void GSState::HandleAutoFlush()
 		const float K = static_cast<float>(m_context->TEX1.K) / 16;
 		const float powL = static_cast<float>(1 << m_context->TEX1.L);
 
+		GSVector4i xy_coord;
 		GSVector4i tex_coord;
 		float vert_lod = K;
 
 		// Prepare the currently processed vertex.
+		xy_coord.x = (static_cast<int>(m_v.XYZ.X) - static_cast<int>(m_context->XYOFFSET.OFX)) >> 4;
+		xy_coord.y = (static_cast<int>(m_v.XYZ.Y) - static_cast<int>(m_context->XYOFFSET.OFY)) >> 4;
 		if (PRIM->FST)
 		{
 			tex_coord.x = (m_v.U >> 4) >> tex_layer;
@@ -4062,6 +4065,7 @@ __forceinline void GSState::HandleAutoFlush()
 				vert_lod = -std::log2(std::abs(m_v.RGBAQ.Q)) * powL + K;
 		}
 
+		GSVector4i xy_rect = xy_coord.xyxy();
 		GSVector4i tex_rect = tex_coord.xyxy();
 		GSVector2i lod_range = GSVector2i(static_cast<int>(std::floor(vert_lod)), static_cast<int>(std::ceil(vert_lod)));
 
@@ -4072,6 +4076,8 @@ __forceinline void GSState::HandleAutoFlush()
 		{
 			const GSVertex* v = &m_vertex.buff[buff[i]];
 
+			xy_coord.x = (static_cast<int>(v->XYZ.X) - static_cast<int>(m_context->XYOFFSET.OFX)) >> 4;
+			xy_coord.y = (static_cast<int>(v->XYZ.Y) - static_cast<int>(m_context->XYOFFSET.OFY)) >> 4;
 			if (PRIM->FST)
 			{
 				tex_coord.x = (v->U >> 4) >> tex_layer;
@@ -4089,6 +4095,10 @@ __forceinline void GSState::HandleAutoFlush()
 					vert_lod = -std::log2(std::abs(v->RGBAQ.Q)) * powL + K;
 			}
 
+			xy_rect.x = std::min(xy_rect.x, xy_coord.x);
+			xy_rect.z = std::max(xy_rect.z, xy_coord.x);
+			xy_rect.y = std::min(xy_rect.y, xy_coord.y);
+			xy_rect.w = std::max(xy_rect.w, xy_coord.y);
 			tex_rect.x = std::min(tex_rect.x, tex_coord.x);
 			tex_rect.z = std::max(tex_rect.z, tex_coord.x);
 			tex_rect.y = std::min(tex_rect.y, tex_coord.y);
@@ -4102,11 +4112,19 @@ __forceinline void GSState::HandleAutoFlush()
 			return;
 
 		// If the draw was 1 line thick, make it larger as rects are exclusive of ends.
+		if (xy_rect.x == xy_rect.z)
+			xy_rect += GSVector4i::cxpr(0, 0, 1, 0);
+		if (xy_rect.y == xy_rect.w)
+			xy_rect += GSVector4i::cxpr(0, 0, 0, 1);
 		if (tex_rect.x == tex_rect.z)
 			tex_rect += GSVector4i::cxpr(0, 0, 1, 0);
 		if (tex_rect.y == tex_rect.w)
 			tex_rect += GSVector4i::cxpr(0, 0, 0, 1);
 
+		// If the current prim fails the scissor test then we don't need to flush.
+		if (xy_rect.rintersect(m_context->scissor.in).rempty())
+			return;
+
 		// Get the last texture position from the last draw.
 		const GSVertex* v = &m_vertex.buff[m_index.buff[m_index.tail - 1]];