Merge pull request #1439 from Armada651/ogl-stereo-3d

OGL: Stereoscopic 3D Support

1 files changed, 134 insertions, 0 deletions

diff --git a/Source/Core/VideoCommon/GeometryShaderGen.cpp b/Source/Core/VideoCommon/GeometryShaderGen.cpp
new file mode 100644
index 0000000000..83a590a7ed
--- /dev/null
+++ b/Source/Core/VideoCommon/GeometryShaderGen.cpp
@@ -0,0 +1,134 @@
+// Copyright 2013 Dolphin Emulator Project
+// Licensed under GPLv2
+// Refer to the license.txt file included.
+
+#include <cmath>
+#include <locale.h>
+#ifdef __APPLE__
+	#include <xlocale.h>
+#endif
+
+#include "VideoCommon/GeometryShaderGen.h"
+#include "VideoCommon/LightingShaderGen.h"
+#include "VideoCommon/VertexShaderGen.h"
+#include "VideoCommon/VideoConfig.h"
+
+static char text[16384];
+
+template<class T>
+static inline void GenerateGeometryShader(T& out, u32 components, API_TYPE ApiType)
+{
+	// Non-uid template parameters will write to the dummy data (=> gets optimized out)
+	geometry_shader_uid_data dummy_data;
+	geometry_shader_uid_data* uid_data = out.template GetUidData<geometry_shader_uid_data>();
+	if (uid_data == nullptr)
+		uid_data = &dummy_data;
+
+	out.SetBuffer(text);
+	const bool is_writing_shadercode = (out.GetBuffer() != nullptr);
+#ifndef ANDROID
+	locale_t locale;
+	locale_t old_locale;
+	if (is_writing_shadercode)
+	{
+		locale = newlocale(LC_NUMERIC_MASK, "C", nullptr); // New locale for compilation
+		old_locale = uselocale(locale); // Apply the locale for this thread
+	}
+#endif
+
+	if (is_writing_shadercode)
+		text[sizeof(text) - 1] = 0x7C;  // canary
+
+	out.Write("//Geometry Shader for 3D stereoscopy\n");
+
+	uid_data->stereo = g_ActiveConfig.iStereoMode > 0;
+	if (ApiType == API_OPENGL)
+	{
+		// Insert layout parameters
+		if (g_ActiveConfig.backend_info.bSupportsGSInstancing)
+			out.Write("layout(triangles, invocations = %d) in;\n", g_ActiveConfig.iStereoMode > 0 ? 2 : 1);
+		else
+			out.Write("layout(triangles) in;\n");
+		out.Write("layout(triangle_strip, max_vertices = %d) out;\n", g_ActiveConfig.backend_info.bSupportsGSInstancing ? 3 : 6);
+	}
+
+	out.Write("%s", s_lighting_struct);
+
+	// uniforms
+	if (ApiType == API_OPENGL)
+		out.Write("layout(std140%s) uniform VSBlock {\n", g_ActiveConfig.backend_info.bSupportsBindingLayout ? ", binding = 2" : "");
+	else
+		out.Write("cbuffer VSBlock {\n");
+	out.Write(s_shader_uniforms);
+	out.Write("};\n");
+
+	uid_data->numTexGens = xfmem.numTexGen.numTexGens;
+	uid_data->pixel_lighting = g_ActiveConfig.bEnablePixelLighting;
+
+	GenerateVSOutputStruct(out, ApiType);
+
+	out.Write("centroid in VS_OUTPUT o[3];\n");
+	out.Write("centroid out VS_OUTPUT f;\n");
+
+	out.Write("flat out int layer;\n");
+
+	out.Write("void main()\n{\n");
+
+	// If the GPU supports invocation we don't need a for loop and can simply use the
+	// invocation identifier to determine which layer we're rendering.
+	if (g_ActiveConfig.backend_info.bSupportsGSInstancing)
+		out.Write("\tint l = gl_InvocationID;\n");
+	else
+		out.Write("\tfor (int l = 0; l < %d; ++l) {\n", g_ActiveConfig.iStereoMode > 0 ? 2 : 1);
+
+	out.Write("\tfor (int i = 0; i < 3; ++i) {\n");
+	out.Write("\t\tlayer = l;\n");
+	out.Write("\t\tgl_Layer = l;\n");
+	out.Write("\t\tf = o[i];\n");
+	out.Write("\t\tfloat4 pos = o[i].pos;\n");
+
+	if (g_ActiveConfig.iStereoMode > 0)
+	{
+		// For stereoscopy add a small horizontal offset in Normalized Device Coordinates proportional
+		// to the depth of the vertex. We retrieve the depth value from the w-component of the projected
+		// vertex which contains the negated z-component of the original vertex.
+		// For negative parallax (out-of-screen effects) we subtract a convergence value from
+		// the depth value. This results in objects at a distance smaller than the convergence
+		// distance to seemingly appear in front of the screen.
+		// This formula is based on page 13 of the "Nvidia 3D Vision Automatic, Best Practices Guide"
+		out.Write("\t\tf.clipPos.x = o[i].clipPos.x + " I_STEREOPARAMS"[l] * (o[i].clipPos.w - " I_STEREOPARAMS"[2]);\n");
+		out.Write("\t\tpos.x = o[i].pos.x + " I_STEREOPARAMS"[l] * (o[i].pos.w - " I_STEREOPARAMS"[2]);\n");
+	}
+
+	out.Write("\t\tf.pos.x = pos.x;\n");
+	out.Write("\t\tgl_Position = pos;\n");
+	out.Write("\t\tEmitVertex();\n");
+	out.Write("\t}\n");
+	out.Write("\tEndPrimitive();\n");
+
+	if (!g_ActiveConfig.backend_info.bSupportsGSInstancing)
+		out.Write("\t}\n");
+
+	out.Write("}\n");
+
+	if (is_writing_shadercode)
+	{
+		if (text[sizeof(text) - 1] != 0x7C)
+			PanicAlert("GeometryShader generator - buffer too small, canary has been eaten!");
+
+#ifndef ANDROID
+		uselocale(old_locale); // restore locale
+		freelocale(locale);
+#endif
+	}
+}
+
+void GetGeometryShaderUid(GeometryShaderUid& object, u32 components, API_TYPE ApiType)
+{
+	GenerateGeometryShader<GeometryShaderUid>(object, components, ApiType);
+}
+
+void GenerateGeometryShaderCode(ShaderCode& object, u32 components, API_TYPE ApiType)
+{
+	GenerateGeometryShader<ShaderCode>(object, components, ApiType);
+}