gsdx ogl: Unscale line

Line thickness will be increased to N pixels (N is the upscaling factor).

Code will also be enabled by UserHacks_unscale_point_line = 1

plugins/GSdx/GSRendererOGL.cpp

@@ -1319,16 +1319,29 @@ void GSRendererOGL::DrawPrims(GSTexture* rt, GSTexture* ds, GSTextureCache::Sour
 
 
 	// GS
-#if 1
+	bool unscale_hack = UserHacks_unscale_pt_ln  & (GetUpscaleMultiplier() > 1) & GLLoader::found_geometry_shader;
-	if (UserHacks_unscale_pt_ln && m_vt.m_primclass == GS_POINT_CLASS) {
+	switch(m_vt.m_primclass)
-		// Upscaling point will create aliasing because point has a size of 0 pixels.
+	{
-		// This code tries to replace point with sprite. So a point in 4x will be replaced by
+		case GS_POINT_CLASS:
-		// a 4x4 flat sprite.
+			if (unscale_hack) {
-		m_gs_sel.point = 1;
+				m_gs_sel.point = 1;
-		vs_cb.PointSize = GSVector2(2.0f * rtscale.x / rtsize.x, 2.0f * rtscale.y / rtsize.y);
+				vs_cb.PointSize = GSVector2(2.0f * rtscale.x / rtsize.x, 2.0f * rtscale.y / rtsize.y);
+			}
+			break;
+		case GS_LINE_CLASS:
+			if (unscale_hack) {
+				m_gs_sel.line = 1;
+				vs_cb.PointSize = GSVector2(2.0f * rtscale.x / rtsize.x, 2.0f * rtscale.y / rtsize.y);
+			}
+			break;
+		case GS_SPRITE_CLASS:
+			m_gs_sel.sprite = 1;
+			break;
+		case GS_TRIANGLE_CLASS:
+			break;
+		default:
+			__assume(0);
 	}
-#endif
-	m_gs_sel.sprite = m_vt.m_primclass == GS_SPRITE_CLASS;
 
 	dev->SetupPipeline(m_vs_sel, m_gs_sel, m_ps_sel);
 

plugins/GSdx/res/glsl/tfx_vgs.glsl

@@ -144,6 +144,47 @@ void gs_main()
     EndPrimitive();
 }
 
+#elif GS_LINE == 1
+
+void gs_main()
+{
+    // Transform a line to a thick line-sprite
+    vertex right = vertex(GSin[1].t_float, GSin[1].t_int, GSin[1].c);
+    vertex left  = vertex(GSin[0].t_float, GSin[0].t_int, GSin[0].c);
+    vec4 lt_p = gl_in[0].gl_Position;
+    vec4 rt_p = gl_in[1].gl_Position;
+
+    // Potentially there is faster math
+    vec2 line_vector = normalize(rt_p.xy - lt_p.xy);
+    vec2 line_normal = vec2(line_vector.y, -line_vector.x);
+    vec2 line_width  = line_normal * PointSize;
+
+    vec4 lb_p = gl_in[0].gl_Position + vec4(line_width, 0.0f, 0.0f);
+    vec4 rb_p = gl_in[1].gl_Position + vec4(line_width, 0.0f, 0.0f);
+
+    // Triangle 1
+    gl_Position = lt_p;
+    out_vertex(left);
+
+    gl_Position = lb_p;
+    out_vertex(left);
+
+    gl_Position = rt_p;
+    out_vertex(right);
+    EndPrimitive();
+
+    // Triangle 2
+    gl_Position = lb_p;
+    out_vertex(left);
+
+    gl_Position = rt_p;
+    out_vertex(right);
+
+    gl_Position = rb_p;
+    out_vertex(right);
+    EndPrimitive();
+}
+
 #else
 
 void gs_main()

plugins/GSdx/res/glsl_source.h

@@ -811,6 +811,47 @@ static const char* const tfx_vgs_glsl =
 	"    EndPrimitive();\n"
 	"}\n"
 	"\n"
+	"#elif GS_LINE == 1\n"
+	"\n"
+	"void gs_main()\n"
+	"{\n"
+	"    // Transform a line to a thick line-sprite\n"
+	"    vertex right = vertex(GSin[1].t_float, GSin[1].t_int, GSin[1].c);\n"
+	"    vertex left  = vertex(GSin[0].t_float, GSin[0].t_int, GSin[0].c);\n"
+	"    vec4 lt_p = gl_in[0].gl_Position;\n"
+	"    vec4 rt_p = gl_in[1].gl_Position;\n"
+	"\n"
+	"    // Potentially there is faster math\n"
+	"    vec2 line_vector = normalize(rt_p.xy - lt_p.xy);\n"
+	"    vec2 line_normal = vec2(line_vector.y, -line_vector.x);\n"
+	"    vec2 line_width  = line_normal * PointSize;\n"
+	"\n"
+	"    vec4 lb_p = gl_in[0].gl_Position + vec4(line_width, 0.0f, 0.0f);\n"
+	"    vec4 rb_p = gl_in[1].gl_Position + vec4(line_width, 0.0f, 0.0f);\n"
+	"\n"
+	"    // Triangle 1\n"
+	"    gl_Position = lt_p;\n"
+	"    out_vertex(left);\n"
+	"\n"
+	"    gl_Position = lb_p;\n"
+	"    out_vertex(left);\n"
+	"\n"
+	"    gl_Position = rt_p;\n"
+	"    out_vertex(right);\n"
+	"    EndPrimitive();\n"
+	"\n"
+	"    // Triangle 2\n"
+	"    gl_Position = lb_p;\n"
+	"    out_vertex(left);\n"
+	"\n"
+	"    gl_Position = rt_p;\n"
+	"    out_vertex(right);\n"
+	"\n"
+	"    gl_Position = rb_p;\n"
+	"    out_vertex(right);\n"
+	"    EndPrimitive();\n"
+	"}\n"
+	"\n"
 	"#else\n"
 	"\n"
 	"void gs_main()\n"