Merge pull request #4164 from Armada651/sonic-clipping

VertexShaderGen: Move the sonic epsilon hack to the vertex shader.

2 files changed, 7 insertions, 7 deletions

diff --git a/Source/Core/VideoCommon/VertexShaderGen.cpp b/Source/Core/VideoCommon/VertexShaderGen.cpp
index ba7fc3a02e..8376d6b8ea 100644
--- a/Source/Core/VideoCommon/VertexShaderGen.cpp
+++ b/Source/Core/VideoCommon/VertexShaderGen.cpp
@@ -420,8 +420,11 @@ ShaderCode GenerateVertexShaderCode(APIType api_type, const vertex_shader_uid_da
 
     // Since we're adjusting z for the depth range before the perspective divide, we have to do our
     // own clipping. We want to clip so that -w <= z <= 0, which matches the console -1..0 range.
-    out.Write("o.clipDist0 = o.pos.z + o.pos.w;\n");  // Near: z < -w
-    out.Write("o.clipDist1 = -o.pos.z;\n");           // Far: z > 0
+    // We adjust our depth value for clipping purposes to match the perspective projection in the
+    // software backend, which is a hack to fix Sonic Adventure and Unleashed games.
+    out.Write("float clipDepth = o.pos.z * (1.0 - 1e-7);\n");
+    out.Write("o.clipDist0 = clipDepth + o.pos.w;\n");  // Near: z < -w
+    out.Write("o.clipDist1 = -clipDepth;\n");           // Far: z > 0
 
     // Adjust z for the depth range. We're using an equation which incorperates a depth inversion,
     // so we can map the console -1..0 range to the 0..1 range used in the depth buffer.
diff --git a/Source/Core/VideoCommon/VertexShaderManager.cpp b/Source/Core/VideoCommon/VertexShaderManager.cpp
index e8f82d0bf5..11f5be0ab5 100644
--- a/Source/Core/VideoCommon/VertexShaderManager.cpp
+++ b/Source/Core/VideoCommon/VertexShaderManager.cpp
@@ -454,8 +454,7 @@ void VertexShaderManager::SetConstants()
       g_fProjectionMatrix[12] = 0.0f;
       g_fProjectionMatrix[13] = 0.0f;
 
-      // Hack to fix depth clipping precision issues (such as Sonic Adventure UI)
-      g_fProjectionMatrix[14] = -(1.0f + FLT_EPSILON);
+      g_fProjectionMatrix[14] = -1.0f;
       g_fProjectionMatrix[15] = 0.0f;
 
       // Heuristic to detect if a GameCube game is in 16:9 anamorphic widescreen mode.
@@ -511,9 +510,7 @@ void VertexShaderManager::SetConstants()
       g_fProjectionMatrix[13] = 0.0f;
 
       g_fProjectionMatrix[14] = 0.0f;
-
-      // Hack to fix depth clipping precision issues (such as Sonic Unleashed UI)
-      g_fProjectionMatrix[15] = 1.0f + FLT_EPSILON;
+      g_fProjectionMatrix[15] = 1.0f;
 
       SETSTAT_FT(stats.g2proj_0, g_fProjectionMatrix[0]);
       SETSTAT_FT(stats.g2proj_1, g_fProjectionMatrix[1]);