diff --git a/GPU/Common/GPUStateUtils.cpp b/GPU/Common/GPUStateUtils.cpp
index 2c17f94d24..9fc2d2c6b5 100644
--- a/GPU/Common/GPUStateUtils.cpp
+++ b/GPU/Common/GPUStateUtils.cpp
@@ -136,6 +136,7 @@ bool IsColorTestTriviallyTrue() {
 	}
 }
 
+// TODO: Pack into 16-bit integer.
 const bool nonAlphaSrcFactors[16] = {
 	true,  // GE_SRCBLEND_DSTCOLOR,
 	true,  // GE_SRCBLEND_INVDSTCOLOR,
diff --git a/GPU/Common/ShaderCommon.h b/GPU/Common/ShaderCommon.h
index 5f17e236dc..ab03277e58 100644
--- a/GPU/Common/ShaderCommon.h
+++ b/GPU/Common/ShaderCommon.h
@@ -76,6 +76,8 @@ enum : uint64_t {
 	DIRTY_TEXCLAMP = 1ULL << 19,
 	DIRTY_DEPTHRANGE = 1ULL << 19,
 
+	DIRTY_GUARDBAND = 1ULL << 20,
+
 	DIRTY_WORLDMATRIX = 1ULL << 21,
 	DIRTY_VIEWMATRIX = 1ULL << 22,
 	DIRTY_TEXMATRIX = 1ULL << 23,
diff --git a/GPU/Common/ShaderUniforms.cpp b/GPU/Common/ShaderUniforms.cpp
index 4e3a3deab4..f54c3f16d3 100644
--- a/GPU/Common/ShaderUniforms.cpp
+++ b/GPU/Common/ShaderUniforms.cpp
@@ -23,6 +23,25 @@ static void ConvertProjMatrixToD3D11(Matrix4x4 &in) {
 	in.translateAndScale(trans, scale);
 }
 
+void ComputeGuardband(float gb[4], float zmin) {
+	float vpWidth = fabsf(gstate_c.vpWidth);
+	float vpHeight = fabsf(gstate_c.vpHeight);
+	// Avoid bad values during initialization. Doubt these are really needed.
+	if (vpWidth == 0.0)
+		vpWidth = 480;
+	if (vpHeight == 0.0)
+		vpHeight = 272;
+
+	// We assume a symmetric guardband, even though it's not entirely correct to do so - but nearly everything does it
+	// this way and we have space for the NAN in the uniform.
+	// We also assume that everything behind the near clipping plane gets clipped and will thus not in reality
+	// exceed the guardband. This is a bit rough but should be ok.
+	gb[0] = (2048.0f / (vpWidth*0.5f));
+	gb[1] = (2048.0f / (vpHeight*0.5f));
+	gb[2] = zmin;
+	gb[3] = NAN;
+}
+
 void BaseUpdateUniforms(UB_VS_FS_Base *ub, uint64_t dirtyUniforms, bool flipViewport) {
 	if (dirtyUniforms & DIRTY_TEXENV) {
 		Uint8x3ToFloat4(ub->texEnvColor, gstate.texenvcolor);
@@ -56,7 +75,11 @@ void BaseUpdateUniforms(UB_VS_FS_Base *ub, uint64_t dirtyUniforms, bool flipView
 		ub->texClampOffset[0] = gstate_c.curTextureXOffset * invW;
 		ub->texClampOffset[1] = gstate_c.curTextureYOffset * invH;
 	}
-
+	if (dirtyUniforms & DIRTY_GUARDBAND) {
+		float gb[4];
+		ComputeGuardband(gb, 0.0f);
+		memcpy(ub->guardband, gb, sizeof(float) * 4);
+	}
 	if (dirtyUniforms & DIRTY_PROJMATRIX) {
 		Matrix4x4 flippedMatrix;
 		memcpy(&flippedMatrix, gstate.projMatrix, 16 * sizeof(float));
@@ -98,6 +121,7 @@ void BaseUpdateUniforms(UB_VS_FS_Base *ub, uint64_t dirtyUniforms, bool flipView
 		if (g_Config.iRenderingMode == 0 && g_display_rotation != DisplayRotation::ROTATE_0) {
 			proj_through = proj_through * g_display_rot_matrix;
 		}
+		// proj_through.translateAndScale(Vec3(0, 0, 0), Vec3(1.0f / debugscale, 1.0f / debugscale, 0));
 		CopyMatrix4x4(ub->proj_through, proj_through.getReadPtr());
 	}
 
diff --git a/GPU/Common/ShaderUniforms.h b/GPU/Common/ShaderUniforms.h
index 55f08f7658..c1b04e8bf3 100644
--- a/GPU/Common/ShaderUniforms.h
+++ b/GPU/Common/ShaderUniforms.h
@@ -10,7 +10,7 @@
 enum : uint64_t {
 	DIRTY_BASE_UNIFORMS =
 	DIRTY_WORLDMATRIX | DIRTY_PROJTHROUGHMATRIX | DIRTY_VIEWMATRIX | DIRTY_TEXMATRIX | DIRTY_ALPHACOLORREF |
-	DIRTY_PROJMATRIX | DIRTY_FOGCOLOR | DIRTY_FOGCOEF | DIRTY_TEXENV | DIRTY_STENCILREPLACEVALUE |
+	DIRTY_PROJMATRIX | DIRTY_FOGCOLOR | DIRTY_FOGCOEF | DIRTY_TEXENV | DIRTY_STENCILREPLACEVALUE | DIRTY_GUARDBAND |
 	DIRTY_ALPHACOLORMASK | DIRTY_SHADERBLEND | DIRTY_UVSCALEOFFSET | DIRTY_TEXCLAMP | DIRTY_DEPTHRANGE | DIRTY_MATAMBIENTALPHA |
 	DIRTY_BEZIERSPLINE,
 	DIRTY_LIGHT_UNIFORMS =
@@ -34,6 +34,7 @@ struct UB_VS_FS_Base {
 	int spline_count_v;
 	int spline_type_u;
 	int spline_type_v;
+	float guardband[4];
 	// Fragment data
 	float fogColor[4];
 	float texEnvColor[4];
@@ -59,6 +60,8 @@ R"(  mat4 proj_mtx;
   int spline_count_v;
   int spline_type_u;
   int spline_type_v;
+  vec4 guardband;
+  // Fragment
   vec3 fogcolor;
   vec3 texenv;
   ivec4 alphacolorref;
@@ -84,6 +87,8 @@ R"(  float4x4 u_proj;
   int u_spline_count_v;
   int u_spline_type_u;
   int u_spline_type_v;
+  float4 u_guardband;
+  // Fragment
   float3 u_fogcolor;
   float3 u_texenv;
   uint4 u_alphacolorref;
@@ -184,3 +189,5 @@ void BaseUpdateUniforms(UB_VS_FS_Base *ub, uint64_t dirtyUniforms, bool flipView
 void LightUpdateUniforms(UB_VS_Lights *ub, uint64_t dirtyUniforms);
 void BoneUpdateUniforms(UB_VS_Bones *ub, uint64_t dirtyUniforms);
 
+// Shared helper functions
+void ComputeGuardband(float gb[4], float zmin);
diff --git a/GPU/Directx9/ShaderManagerDX9.cpp b/GPU/Directx9/ShaderManagerDX9.cpp
index 05da5bba0b..cfd0f5cff2 100644
--- a/GPU/Directx9/ShaderManagerDX9.cpp
+++ b/GPU/Directx9/ShaderManagerDX9.cpp
@@ -35,6 +35,7 @@
 #include "GPU/Math3D.h"
 #include "GPU/GPUState.h"
 #include "GPU/ge_constants.h"
+#include "GPU/Common/ShaderUniforms.h"
 #include "GPU/Directx9/ShaderManagerDX9.h"
 #include "GPU/Directx9/DrawEngineDX9.h"
 #include "GPU/Directx9/FramebufferDX9.h"
@@ -378,6 +379,11 @@ void ShaderManagerDX9::VSUpdateUniforms(u64 dirtyUniforms) {
 #endif
 		VSSetFloatArray(CONST_VS_FOGCOEF, fogcoef, 2);
 	}
+	if (dirtyUniforms & DIRTY_GUARDBAND) {
+		float gb[4];
+		ComputeGuardband(gb, 0.0f);
+		VSSetFloatUniform4(CONST_VS_GUARDBAND, gb);
+	}
 	// TODO: Could even set all bones in one go if they're all dirty.
 #ifdef USE_BONE_ARRAY
 	if (u_bone != 0) {
diff --git a/GPU/Directx9/VertexShaderGeneratorDX9.cpp b/GPU/Directx9/VertexShaderGeneratorDX9.cpp
index 152e2c3fa6..fb5826c7a1 100644
--- a/GPU/Directx9/VertexShaderGeneratorDX9.cpp
+++ b/GPU/Directx9/VertexShaderGeneratorDX9.cpp
@@ -38,6 +38,13 @@
 
 namespace DX9 {
 
+// The PSP does not have a proper triangle clipper on the sides. It does have on for the front plane.
+// It has a guard band though and can rasterize rather large
+// triangles that go outside the viewport. However, there are limits, and it will drop triangles that are very
+// large. Some games appear to draw broken geometry, probably game bugs that were never discovered because the PSP
+// would drop the geometry, including Parappa The Rapper in an obscure case and Outrun. Try to get rid of those
+// triangles by setting the W of one of the vertices to NaN if they are discovered.
+
 static const char * const boneWeightAttrDecl[9] = {	
 	"#ERROR#",
 	"float  a_w1:TEXCOORD1;\n",
@@ -56,6 +63,26 @@ enum DoLightComputation {
 	LIGHT_FULL,
 };
 
+// #define COLORGUARDBAND
+
+#ifdef COLORGUARDBAND
+// Coloring debug version
+static void WriteGuardBand(char *&p) {
+	WRITE(p, "  if (outPos.w >= 0.0) {\n");
+	WRITE(p, "		float3 projPos = outPos.xyz / outPos.w; \n");
+	WRITE(p, "		if (projPos.z >= 0.0 && projPos.z <= 1.0 && (abs(projPos.x) > u_guardband.x || projPos.y > u_guardband.y)) colorOverride.g = 0.0;\n");//outPos.w = u_guardband.w;\n");
+	WRITE(p, "  } else { colorOverride.b = 0.0; } \n");
+}
+#else
+// NOTE: We are skipping the bottom check. This fixes TOCA but I am dubious about it...
+static void WriteGuardBand(char *&p) {
+	WRITE(p, "  if (outPos.w >= 0.0) {\n");
+	WRITE(p, "		float3 projPos = outPos.xyz / outPos.w; \n");
+	WRITE(p, "		if (projPos.z >= 0.0 && projPos.z <= 1.0 && (abs(projPos.x) > u_guardband.x || abs(projPos.y) > u_guardband.y)) outPos.w = u_guardband.w;\n");
+	WRITE(p, "  }\n");
+}
+#endif
+
 void GenerateVertexShaderHLSL(const ShaderID &id, char *buffer, ShaderLanguage lang) {
 	char *p = buffer;
 	const u32 vertType = gstate.vertType;
@@ -119,6 +146,7 @@ void GenerateVertexShaderHLSL(const ShaderID &id, char *buffer, ShaderLanguage l
 			WRITE(p, "float4x4 u_proj : register(c%i);\n", CONST_VS_PROJ);
 			// Add all the uniforms we'll need to transform properly.
 		}
+		WRITE(p, "float4 u_guardband : register(c%i);\n", CONST_VS_GUARDBAND);
 
 		if (enableFog) {
 			WRITE(p, "float2 u_fogcoef : register(c%i);\n", CONST_VS_FOGCOEF);
@@ -350,6 +378,9 @@ void GenerateVertexShaderHLSL(const ShaderID &id, char *buffer, ShaderLanguage l
 
 	WRITE(p, "VS_OUT main(VS_IN In) {\n");
 	WRITE(p, "  VS_OUT Out;\n");  
+#ifdef COLORGUARDBAND
+	WRITE(p, "	float4 colorOverride = float4(1.0, 1.0, 1.0, 1.0);\n");
+#endif
 	if (!useHWTransform) {
 		// Simple pass-through of vertex data to fragment shader
 		if (doTexture) {
@@ -373,26 +404,30 @@ void GenerateVertexShaderHLSL(const ShaderID &id, char *buffer, ShaderLanguage l
 		}
 		if (lang == HLSL_D3D11 || lang == HLSL_D3D11_LEVEL9) {
 			if (gstate.isModeThrough()) {
-				WRITE(p, "  Out.gl_Position = mul(u_proj_through, float4(In.position.xyz, 1.0));\n");
+				WRITE(p, "  float4 outPos = mul(u_proj_through, float4(In.position.xyz, 1.0));\n");
 			} else {
 				if (gstate_c.Supports(GPU_ROUND_DEPTH_TO_16BIT)) {
-					WRITE(p, "  Out.gl_Position = depthRoundZVP(mul(u_proj, float4(In.position.xyz, 1.0)));\n");
+					WRITE(p, "  float4 outPos = depthRoundZVP(mul(u_proj, float4(In.position.xyz, 1.0)));\n");
 				} else {
-					WRITE(p, "  Out.gl_Position = mul(u_proj, float4(In.position.xyz, 1.0));\n");
+					WRITE(p, "  float4 outPos = mul(u_proj, float4(In.position.xyz, 1.0));\n");
 				}
 			}
 		} else {
 			if (gstate.isModeThrough()) {
-				WRITE(p, "  Out.gl_Position = mul(float4(In.position.xyz, 1.0), u_proj_through);\n");
+				WRITE(p, "  float4 outPos = mul(float4(In.position.xyz, 1.0), u_proj_through);\n");
 			} else {
 				if (gstate_c.Supports(GPU_ROUND_DEPTH_TO_16BIT)) {
-					WRITE(p, "  Out.gl_Position = depthRoundZVP(mul(float4(In.position.xyz, 1.0), u_proj));\n");
+					WRITE(p, "  float4 outPos = depthRoundZVP(mul(float4(In.position.xyz, 1.0), u_proj));\n");
 				} else {
-					WRITE(p, "  Out.gl_Position = mul(float4(In.position.xyz, 1.0), u_proj);\n");
+					WRITE(p, "  float4 outPos = mul(float4(In.position.xyz, 1.0), u_proj);\n");
 				}
 			}
 		}
-	}  else {
+		if (lang != HLSL_DX9) {
+			WriteGuardBand(p);
+		}
+		WRITE(p, "  Out.gl_Position = outPos;\n");
+	} else {
 		// Step 1: World Transform / Skinning
 		if (!enableBones) {
 			// Hardware tessellation
@@ -578,18 +613,20 @@ void GenerateVertexShaderHLSL(const ShaderID &id, char *buffer, ShaderLanguage l
 		if (lang == HLSL_D3D11 || lang == HLSL_D3D11_LEVEL9) {
 			// Final view and projection transforms.
 			if (gstate_c.Supports(GPU_ROUND_DEPTH_TO_16BIT)) {
-				WRITE(p, "  Out.gl_Position = depthRoundZVP(mul(u_proj, viewPos));\n");
+				WRITE(p, "  float4 outPos = depthRoundZVP(mul(u_proj, viewPos));\n");
 			} else {
-				WRITE(p, "  Out.gl_Position = mul(u_proj, viewPos);\n");
+				WRITE(p, "  float4 outPos = mul(u_proj, viewPos);\n");
 			}
 		} else {
 			// Final view and projection transforms.
 			if (gstate_c.Supports(GPU_ROUND_DEPTH_TO_16BIT)) {
-				WRITE(p, "  Out.gl_Position = depthRoundZVP(mul(viewPos, u_proj));\n");
+				WRITE(p, "  float4 outPos = depthRoundZVP(mul(viewPos, u_proj));\n");
 			} else {
-				WRITE(p, "  Out.gl_Position = mul(viewPos, u_proj);\n");
+				WRITE(p, "  float4 outPos = mul(viewPos, u_proj);\n");
 			}
 		}
+		WriteGuardBand(p);
+		WRITE(p, "  Out.gl_Position = outPos;\n");
 
 		// TODO: Declare variables for dots for shade mapping if needed.
 
@@ -807,6 +844,9 @@ void GenerateVertexShaderHLSL(const ShaderID &id, char *buffer, ShaderLanguage l
 		}
 	}
 
+#ifdef COLORGUARDBAND
+	WRITE(p, "  Out.v_color0 *= colorOverride;\n");
+#endif
 	WRITE(p, "  return Out;\n");
 	WRITE(p, "}\n");
 }
diff --git a/GPU/Directx9/VertexShaderGeneratorDX9.h b/GPU/Directx9/VertexShaderGeneratorDX9.h
index 690e133979..b941d4d2fe 100644
--- a/GPU/Directx9/VertexShaderGeneratorDX9.h
+++ b/GPU/Directx9/VertexShaderGeneratorDX9.h
@@ -55,5 +55,6 @@ namespace DX9 {
 #define CONST_VS_LIGHTSPECULAR 75
 #define CONST_VS_LIGHTAMBIENT 79
 #define CONST_VS_DEPTHRANGE 83
+#define CONST_VS_GUARDBAND 84
 
 };
diff --git a/GPU/GLES/ShaderManagerGLES.cpp b/GPU/GLES/ShaderManagerGLES.cpp
index c6ebda7579..b01fe1f228 100644
--- a/GPU/GLES/ShaderManagerGLES.cpp
+++ b/GPU/GLES/ShaderManagerGLES.cpp
@@ -41,6 +41,7 @@
 #include "ext/native/gfx/GLStateCache.h"
 #include "GPU/GLES/ShaderManagerGLES.h"
 #include "GPU/GLES/DrawEngineGLES.h"
+#include "GPU/Common/ShaderUniforms.h"
 #include "FramebufferManagerGLES.h"
 
 Shader::Shader(const char *code, uint32_t glShaderType, bool useHWTransform)
@@ -210,6 +211,7 @@ LinkedShader::LinkedShader(ShaderID VSID, Shader *vs, ShaderID FSID, Shader *fs,
 	u_uvscaleoffset = glGetUniformLocation(program, "u_uvscaleoffset");
 	u_texclamp = glGetUniformLocation(program, "u_texclamp");
 	u_texclampoff = glGetUniformLocation(program, "u_texclampoff");
+	u_guardband = glGetUniformLocation(program, "u_guardband");
 
 	for (int i = 0; i < 4; i++) {
 		char temp[64];
@@ -268,7 +270,8 @@ LinkedShader::LinkedShader(ShaderID VSID, Shader *vs, ShaderID FSID, Shader *fs,
 	if (u_blendFixA != -1 || u_blendFixB != -1 || u_fbotexSize != -1) availableUniforms |= DIRTY_SHADERBLEND;
 	if (u_depthRange != -1)
 		availableUniforms |= DIRTY_DEPTHRANGE;
-
+	if (u_guardband != -1)
+		availableUniforms |= DIRTY_GUARDBAND;
 	// Looping up to numBones lets us avoid checking u_bone[i]
 #ifdef USE_BONE_ARRAY
 	if (u_bone != -1) {
@@ -601,6 +604,13 @@ void LinkedShader::UpdateUniforms(u32 vertType, const ShaderID &vsid) {
 	if (dirty & DIRTY_TEXMATRIX) {
 		SetMatrix4x3(u_texmtx, gstate.tgenMatrix);
 	}
+
+	if (dirty & DIRTY_GUARDBAND) {
+		float gb[4];
+		ComputeGuardband(gb, 0.0f);
+		SetFloatUniform4(u_guardband, gb);
+	}
+
 	if ((dirty & DIRTY_DEPTHRANGE) && u_depthRange != -1) {
 		// Since depth is [-1, 1] mapping to [minz, maxz], this is easyish.
 		float vpZScale = gstate.getViewportZScale();
diff --git a/GPU/GLES/ShaderManagerGLES.h b/GPU/GLES/ShaderManagerGLES.h
index 0f1065a25c..4a7b2c00d7 100644
--- a/GPU/GLES/ShaderManagerGLES.h
+++ b/GPU/GLES/ShaderManagerGLES.h
@@ -96,6 +96,9 @@ public:
 	int u_texclamp;
 	int u_texclampoff;
 
+	// Clipping
+	int u_guardband;
+
 	// Lighting
 	int u_ambient;
 	int u_matambientalpha;
diff --git a/GPU/GLES/VertexShaderGeneratorGLES.cpp b/GPU/GLES/VertexShaderGeneratorGLES.cpp
index 719b5cd159..571915f0de 100644
--- a/GPU/GLES/VertexShaderGeneratorGLES.cpp
+++ b/GPU/GLES/VertexShaderGeneratorGLES.cpp
@@ -69,6 +69,12 @@ enum DoLightComputation {
 	LIGHT_FULL,
 };
 
+static void WriteGuardBand(char *&p) {
+	WRITE(p, "  vec3 projPos = outPos.xyz / outPos.w; \n");
+	WRITE(p, "  if (outPos.w >= u_guardband.z) {\n");
+	WRITE(p, "		if (abs(projPos.x) > u_guardband.x || projPos.y < -u_guardband.y) outPos.w = u_guardband.w;\n");
+	WRITE(p, "  }\n");
+}
 
 // Depth range and viewport
 //
@@ -95,6 +101,7 @@ enum DoLightComputation {
 // TODO: Skip all this if we can actually get a 16-bit depth buffer along with stencil, which
 // is a bit of a rare configuration, although quite common on mobile.
 
+// NOTE: We are skipping the bottom check. This fixes TOCA but I am dubious about it...
 
 void GenerateVertexShader(const ShaderID &id, char *buffer) {
 	char *p = buffer;
@@ -247,6 +254,7 @@ void GenerateVertexShader(const ShaderID &id, char *buffer) {
 		WRITE(p, "uniform mat4 u_proj;\n");
 		// Add all the uniforms we'll need to transform properly.
 	}
+	WRITE(p, "uniform vec4 u_guardband;\n");
 
 	bool scaleUV = !throughmode && (uvGenMode == GE_TEXMAP_TEXTURE_COORDS || uvGenMode == GE_TEXMAP_UNKNOWN);
 
@@ -452,15 +460,17 @@ void GenerateVertexShader(const ShaderID &id, char *buffer) {
 			WRITE(p, "  v_fogdepth = position.w;\n");
 		}
 		if (isModeThrough)	{
-			WRITE(p, "  gl_Position = u_proj_through * vec4(position.xyz, 1.0);\n");
+			WRITE(p, "  vec4 outPos = u_proj_through * vec4(position.xyz, 1.0);\n");
 		} else {
 			// The viewport is used in this case, so need to compensate for that.
 			if (gstate_c.Supports(GPU_ROUND_DEPTH_TO_16BIT)) {
-				WRITE(p, "  gl_Position = depthRoundZVP(u_proj * vec4(position.xyz, 1.0));\n");
+				WRITE(p, "  vec4 outPos = depthRoundZVP(u_proj * vec4(position.xyz, 1.0));\n");
 			} else {
-				WRITE(p, "  gl_Position = u_proj * vec4(position.xyz, 1.0);\n");
+				WRITE(p, "  vec4 outPos = u_proj * vec4(position.xyz, 1.0);\n");
 			}
 		}
+		WriteGuardBand(p);
+		WRITE(p, "  gl_Position = outPos;\n");
 	} else {
 		// Step 1: World Transform / Skinning
 		if (!enableBones) {
@@ -652,10 +662,12 @@ void GenerateVertexShader(const ShaderID &id, char *buffer) {
 
 		// Final view and projection transforms.
 		if (gstate_c.Supports(GPU_ROUND_DEPTH_TO_16BIT)) {
-			WRITE(p, "  gl_Position = depthRoundZVP(u_proj * viewPos);\n");
+			WRITE(p, "  vec4 outPos = depthRoundZVP(u_proj * viewPos);\n");
 		} else {
-			WRITE(p, "  gl_Position = u_proj * viewPos;\n");
+			WRITE(p, "  vec4 outPos = u_proj * viewPos;\n");
 		}
+		WriteGuardBand(p);
+		WRITE(p, "  gl_Position = outPos;\n");
 
 		// TODO: Declare variables for dots for shade mapping if needed.
 
diff --git a/GPU/GPUCommon.cpp b/GPU/GPUCommon.cpp
index a873beced6..3ceac395c5 100644
--- a/GPU/GPUCommon.cpp
+++ b/GPU/GPUCommon.cpp
@@ -172,12 +172,12 @@ const CommonCommandTableEntry commonCommandTable[] = {
 	{ GE_CMD_ANTIALIASENABLE, FLAG_FLUSHBEFOREONCHANGE },
 
 	// Viewport.
-	{ GE_CMD_OFFSETX, FLAG_FLUSHBEFOREONCHANGE, DIRTY_VIEWPORTSCISSOR_STATE },
-	{ GE_CMD_OFFSETY, FLAG_FLUSHBEFOREONCHANGE, DIRTY_VIEWPORTSCISSOR_STATE },
-	{ GE_CMD_VIEWPORTXSCALE, FLAG_FLUSHBEFOREONCHANGE,  DIRTY_FRAMEBUF | DIRTY_TEXTURE_PARAMS | DIRTY_VIEWPORTSCISSOR_STATE },
-	{ GE_CMD_VIEWPORTYSCALE, FLAG_FLUSHBEFOREONCHANGE,  DIRTY_FRAMEBUF | DIRTY_TEXTURE_PARAMS | DIRTY_VIEWPORTSCISSOR_STATE },
-	{ GE_CMD_VIEWPORTXCENTER, FLAG_FLUSHBEFOREONCHANGE, DIRTY_FRAMEBUF | DIRTY_TEXTURE_PARAMS | DIRTY_VIEWPORTSCISSOR_STATE },
-	{ GE_CMD_VIEWPORTYCENTER, FLAG_FLUSHBEFOREONCHANGE, DIRTY_FRAMEBUF | DIRTY_TEXTURE_PARAMS | DIRTY_VIEWPORTSCISSOR_STATE },
+	{ GE_CMD_OFFSETX, FLAG_FLUSHBEFOREONCHANGE, DIRTY_VIEWPORTSCISSOR_STATE | DIRTY_GUARDBAND},
+	{ GE_CMD_OFFSETY, FLAG_FLUSHBEFOREONCHANGE, DIRTY_VIEWPORTSCISSOR_STATE | DIRTY_GUARDBAND},
+	{ GE_CMD_VIEWPORTXSCALE, FLAG_FLUSHBEFOREONCHANGE,  DIRTY_FRAMEBUF | DIRTY_TEXTURE_PARAMS | DIRTY_VIEWPORTSCISSOR_STATE | DIRTY_GUARDBAND},
+	{ GE_CMD_VIEWPORTYSCALE, FLAG_FLUSHBEFOREONCHANGE,  DIRTY_FRAMEBUF | DIRTY_TEXTURE_PARAMS | DIRTY_VIEWPORTSCISSOR_STATE | DIRTY_GUARDBAND},
+	{ GE_CMD_VIEWPORTXCENTER, FLAG_FLUSHBEFOREONCHANGE, DIRTY_FRAMEBUF | DIRTY_TEXTURE_PARAMS | DIRTY_VIEWPORTSCISSOR_STATE | DIRTY_GUARDBAND},
+	{ GE_CMD_VIEWPORTYCENTER, FLAG_FLUSHBEFOREONCHANGE, DIRTY_FRAMEBUF | DIRTY_TEXTURE_PARAMS | DIRTY_VIEWPORTSCISSOR_STATE | DIRTY_GUARDBAND},
 	{ GE_CMD_VIEWPORTZSCALE, FLAG_FLUSHBEFOREONCHANGE,  DIRTY_FRAMEBUF | DIRTY_TEXTURE_PARAMS | DIRTY_DEPTHRANGE | DIRTY_PROJMATRIX | DIRTY_VIEWPORTSCISSOR_STATE },
 	{ GE_CMD_VIEWPORTZCENTER, FLAG_FLUSHBEFOREONCHANGE, DIRTY_FRAMEBUF | DIRTY_TEXTURE_PARAMS | DIRTY_DEPTHRANGE | DIRTY_PROJMATRIX | DIRTY_VIEWPORTSCISSOR_STATE },
 	{ GE_CMD_CLIPENABLE, FLAG_FLUSHBEFOREONCHANGE, DIRTY_VIEWPORTSCISSOR_STATE },
diff --git a/GPU/Vulkan/ShaderManagerVulkan.cpp b/GPU/Vulkan/ShaderManagerVulkan.cpp
index fc2d3cae86..1911cbdfbf 100644
--- a/GPU/Vulkan/ShaderManagerVulkan.cpp
+++ b/GPU/Vulkan/ShaderManagerVulkan.cpp
@@ -22,6 +22,7 @@
 #include <map>
 
 #include "base/logging.h"
+#include "base/stringutil.h"
 #include "math/lin/matrix4x4.h"
 #include "math/math_util.h"
 #include "math/dataconv.h"
@@ -64,7 +65,7 @@ VulkanFragmentShader::VulkanFragmentShader(VulkanContext *vulkan, ShaderID id, c
 #ifdef SHADERLOG
 		OutputDebugStringA("Messages:\n");
 		OutputDebugStringA(errorMessage.c_str());
-		OutputDebugStringA(code);
+		OutputDebugStringA(LineNumberString(code).c_str());
 #endif
 		Reporting::ReportMessage("Vulkan error in shader compilation: info: %s / code: %s", errorMessage.c_str(), code);
 	} else {
diff --git a/GPU/Vulkan/VertexShaderGeneratorVulkan.cpp b/GPU/Vulkan/VertexShaderGeneratorVulkan.cpp
index b3e9ae7e13..e7f7307681 100644
--- a/GPU/Vulkan/VertexShaderGeneratorVulkan.cpp
+++ b/GPU/Vulkan/VertexShaderGeneratorVulkan.cpp
@@ -47,11 +47,7 @@ static const char *vulkan_glsl_preamble =
 // texcoord = 2
 // fog = 3
 
-
-
-
 #undef WRITE
-
 #define WRITE p+=sprintf
 
 static const char * const boneWeightDecl[9] = {
@@ -72,6 +68,13 @@ enum DoLightComputation {
 	LIGHT_FULL,
 };
 
+static void WriteGuardBand(char *&p) {
+	WRITE(p, "  vec3 projPos = outPos.xyz / outPos.w; \n");
+	WRITE(p, "  if (outPos.w >= base.guardband.z) {\n");
+	WRITE(p, "		if (abs(projPos.x) > base.guardband.x || projPos.y < -base.guardband.y) outPos.w = base.guardband.w;\n");
+	WRITE(p, "  }\n");
+}
+
 // Depth range and viewport
 //
 // After the multiplication with the projection matrix, we have a 4D vector in clip space.
@@ -317,15 +320,17 @@ bool GenerateVulkanGLSLVertexShader(const ShaderID &id, char *buffer, bool *uses
 			WRITE(p, "  v_fogdepth = position.w;\n");
 		}
 		if (isModeThrough) {
-			WRITE(p, "  gl_Position = base.proj_through_mtx * vec4(position.xyz, 1.0);\n");
+			WRITE(p, "  vec4 outPos = base.proj_through_mtx * vec4(position.xyz, 1.0);\n");
 		} else {
 			// The viewport is used in this case, so need to compensate for that.
 			if (gstate_c.Supports(GPU_ROUND_DEPTH_TO_16BIT)) {
-				WRITE(p, "  gl_Position = depthRoundZVP(base.proj_mtx * vec4(position.xyz, 1.0));\n");
+				WRITE(p, "  vec4 outPos = depthRoundZVP(base.proj_mtx * vec4(position.xyz, 1.0));\n");
 			} else {
-				WRITE(p, "  gl_Position = base.proj_mtx * vec4(position.xyz, 1.0);\n");
+				WRITE(p, "  vec4 outPos = base.proj_mtx * vec4(position.xyz, 1.0);\n");
 			}
 		}
+		WriteGuardBand(p);
+		WRITE(p, "  gl_Position = outPos;\n");
 	} else {
 		// Step 1: World Transform / Skinning
 		if (!enableBones) {
@@ -469,10 +474,12 @@ bool GenerateVulkanGLSLVertexShader(const ShaderID &id, char *buffer, bool *uses
 
 		// Final view and projection transforms.
 		if (gstate_c.Supports(GPU_ROUND_DEPTH_TO_16BIT)) {
-			WRITE(p, "  gl_Position = depthRoundZVP(base.proj_mtx * viewPos);\n");
+			WRITE(p, "  vec4 outPos = depthRoundZVP(base.proj_mtx * viewPos);\n");
 		} else {
-			WRITE(p, "  gl_Position = base.proj_mtx * viewPos;\n");
+			WRITE(p, "  vec4 outPos = base.proj_mtx * viewPos;\n");
 		}
+		WriteGuardBand(p);
+		WRITE(p, "  gl_Position = outPos;\n");
 
 		// TODO: Declare variables for dots for shade mapping if needed.