ioquake3 resync to revision 6925 from 6920.

Allow unwinding of qvmcall64 call-stub for msvc/masm.
Add epsilon to avoid division by zero in CalcSpecular().
Add r_parallaxMapOffset.
Fix line not removed in previous commit.
OpenGL2: Flip normals for backfacing triangles.

engine/Makefile

@@ -44,7 +44,7 @@ ifndef BUILD_DEFINES
 endif
 
 # ioquake3 svn version that this is based on
-IOQ3_REVISION = 6920
+IOQ3_REVISION = 6925
 
 #############################################################################
 #

engine/code/asm/vm_x86_64.asm

@@ -28,19 +28,35 @@
 ; Call to compiled code after setting up the register environment for the VM
 ; prototype:
 ; uint8_t qvmcall64(int *programStack, int *opStack, intptr_t *instructionPointers, byte *dataBase);
+;
+; This call-stub has its own custom calling convention due to pushing all non-volatile registers
+; to the stack. The game uses set/longjmp which on Windows uses "RtlUnwindEx" to unwind the callstack.
+; This function cannot be unwound by default due to the custom calling convention.
+; To allow unwinding, we need to add custom SEH unwind data to the function.
 
-qvmcall64 PROC
+qvmcall64 PROC FRAME
   push r12							; push all non-volatile registers to stack
+  .pushreg r12
   push r13
+  .pushreg r13
   push r14
+  .pushreg r14
   push r15
+  .pushreg r15
   push rdi
+  .pushreg rdi
   push rsi
+  .pushreg rsi
   push rbx
+  .pushreg rbx
   push rbp
+  .pushreg rbp
   
   ; need to save pointer in rcx so we can write back the programData value to caller
   push rcx
+  .pushreg rcx
+  
+  .endprolog						; custom unwind data ends here
 
   ; registers r8 and r9 have correct value already thanx to __fastcall
   xor rbx, rbx						; opStackOfs starts out being 0

engine/code/renderergl2/glsl/lightall_fp.glsl

@@ -89,6 +89,9 @@ float RayIntersectDisplaceMap(vec2 dp, vec2 ds, sampler2D normalMap)
 	// current size of search window
 	float size = 1.0 / float(linearSearchSteps);
 
+	// adjust position if offset above surface
+	dp -= ds * r_parallaxMapOffset;
+
 	// current depth position
 	float depth = 0.0;
 
@@ -141,7 +144,7 @@ float RayIntersectDisplaceMap(vec2 dp, vec2 ds, sampler2D normalMap)
 	}
 #endif
 
-	return bestDepth;
+	return bestDepth - r_parallaxMapOffset;
 }
 
 float LightRay(vec2 dp, vec2 ds, sampler2D normalMap)
@@ -201,7 +204,7 @@ vec3 CalcSpecular(vec3 specular, float NH, float EH, float roughness)
 	float rr = roughness*roughness;
 	float rrrr = rr*rr;
 	float d = (NH * NH) * (rrrr - 1.0) + 1.0;
-	float v = (EH * EH) * (roughness + 0.5);
+	float v = (EH * EH) * (roughness + 0.5) + EPSILON;
 	return specular * (rrrr / (4.0 * d * d * v));
 }
 
@@ -261,7 +264,8 @@ void main()
 	float NL, NH, NE, EH, attenuation;
 
 #if defined(USE_LIGHT) && !defined(USE_FAST_LIGHT)
-	mat3 tangentToWorld = mat3(var_Tangent.xyz, var_Bitangent.xyz, var_Normal.xyz);
+	vec3 surfNormal = (!gl_FrontFacing ? var_Normal : -var_Normal).xyz;
+	mat3 tangentToWorld = mat3(var_Tangent.xyz, var_Bitangent.xyz, surfNormal);
 	viewDir = vec3(var_Normal.w, var_Tangent.w, var_Bitangent.w);
 	E = normalize(viewDir);
 #endif
@@ -332,7 +336,7 @@ void main()
 	N.z = sqrt(clamp((0.25 - N.x * N.x) - N.y * N.y, 0.0, 1.0));
 	N = tangentToWorld * N;
   #else
-	N = var_Normal.xyz;
+	N = surfNormal;
   #endif
 
 	N = normalize(N);
@@ -358,7 +362,7 @@ void main()
 
   #if !defined(USE_LIGHT_VECTOR)
 	ambientColor = lightColor;
-	float surfNL = clamp(dot(var_Normal.xyz, L), 0.0, 1.0);
+	float surfNL = clamp(dot(surfNormal, L), 0.0, 1.0);
 
 	// reserve 25% ambient to avoid black areas on normalmaps
 	lightColor *= 0.75;

engine/code/renderergl2/tr_glsl.c

@@ -1125,6 +1125,8 @@ void GLSL_InitGPUShaders(void)
 
 					if (r_parallaxMapShadows->integer)
 						Q_strcat(extradefines, 1024, "#define USE_PARALLAXMAP_SHADOWS\n");
+
+					Q_strcat(extradefines, 1024, va("#define r_parallaxMapOffset %f\n", r_parallaxMapOffset->value));
 				}
 			}
 

engine/code/renderergl2/tr_init.c

@@ -132,6 +132,7 @@ cvar_t  *r_normalMapping;
 cvar_t  *r_specularMapping;
 cvar_t  *r_deluxeMapping;
 cvar_t  *r_parallaxMapping;
+cvar_t  *r_parallaxMapOffset;
 cvar_t  *r_parallaxMapShadows;
 cvar_t  *r_cubeMapping;
 cvar_t  *r_cubemapSize;
@@ -1243,6 +1244,7 @@ void R_Register( void )
 	r_specularMapping = ri.Cvar_Get( "r_specularMapping", "1", CVAR_ARCHIVE | CVAR_LATCH );
 	r_deluxeMapping = ri.Cvar_Get( "r_deluxeMapping", "1", CVAR_ARCHIVE | CVAR_LATCH );
 	r_parallaxMapping = ri.Cvar_Get( "r_parallaxMapping", "0", CVAR_ARCHIVE | CVAR_LATCH );
+	r_parallaxMapOffset = ri.Cvar_Get( "r_parallaxMapOffset", "0", CVAR_ARCHIVE | CVAR_LATCH );
 	r_parallaxMapShadows = ri.Cvar_Get( "r_parallaxMapShadows", "0", CVAR_ARCHIVE | CVAR_LATCH );
 	r_cubeMapping = ri.Cvar_Get( "r_cubeMapping", "0", CVAR_ARCHIVE | CVAR_LATCH );
 	r_cubemapSize = ri.Cvar_Get( "r_cubemapSize", "128", CVAR_ARCHIVE | CVAR_LATCH );

engine/code/renderergl2/tr_local.h

@@ -1778,6 +1778,7 @@ extern  cvar_t  *r_normalMapping;
 extern  cvar_t  *r_specularMapping;
 extern  cvar_t  *r_deluxeMapping;
 extern  cvar_t  *r_parallaxMapping;
+extern  cvar_t  *r_parallaxMapOffset;
 extern  cvar_t  *r_parallaxMapShadows;
 extern  cvar_t  *r_cubeMapping;
 extern  cvar_t  *r_cubemapSize;

engine/docs/opengl2-readme.md

@@ -184,6 +184,11 @@ Cvars for advanced material usage:
                                      1 - Use parallax occlusion mapping.
                                      2 - Use relief mapping. (slower)
 
+*  `r_parallaxMapOffset`            - Set the parallax height offset.
+                                     0    - Values map to -255 - 0. (default)
+                                     0.5  - Values map to -127 - 127.
+                                     1.0  - Values map to 0 - 255.
+
 *  `r_parallaxMapShadows`           - Enable self-shadowing on parallax map
                                    supported materials.
                                      0 - No. (default)