EEVEE: Fix bump mapping

Fix issue in latest patch and assure derivatives calculation is correct on
all GPU.

3 files changed, 21 insertions, 6 deletions

diff --git a/source/blender/gpu/intern/gpu_extensions.c b/source/blender/gpu/intern/gpu_extensions.c
index 5839b34cd19..0d8e246a2b4 100644
--- a/source/blender/gpu/intern/gpu_extensions.c
+++ b/source/blender/gpu/intern/gpu_extensions.c
@@ -369,6 +369,9 @@ void gpu_extensions_init(void)
   }
 
   /* df/dy calculation factors, those are dependent on driver */
+  GG.dfdyfactors[0] = 1.0;
+  GG.dfdyfactors[1] = 1.0;
+
   if ((strstr(vendor, "ATI") && strstr(version, "3.3.10750"))) {
     GG.dfdyfactors[0] = 1.0;
     GG.dfdyfactors[1] = -1.0;
@@ -383,10 +386,6 @@ void gpu_extensions_init(void)
       GG.dfdyfactors[0] = -1.0;
       GG.dfdyfactors[1] = 1.0;
     }
-    else {
-      GG.dfdyfactors[0] = 1.0;
-      GG.dfdyfactors[1] = 1.0;
-    }
 
     if (strstr(version, "Build 10.18.10.3") || strstr(version, "Build 10.18.10.4") ||
         strstr(version, "Build 10.18.14.4") || strstr(version, "Build 10.18.14.5")) {
diff --git a/source/blender/gpu/intern/gpu_shader.c b/source/blender/gpu/intern/gpu_shader.c
index 3e930d19696..5c2a41d19b3 100644
--- a/source/blender/gpu/intern/gpu_shader.c
+++ b/source/blender/gpu/intern/gpu_shader.c
@@ -275,6 +275,22 @@ static void gpu_shader_standard_defines(char defines[MAX_DEFINE_LENGTH])
     strcat(defines, "#define OS_UNIX\n");
   }
 
+  float derivatives_factors[2];
+  GPU_get_dfdy_factors(derivatives_factors);
+  if (derivatives_factors[0] == 1.0f) {
+    strcat(defines, "#define DFDX_SIGN 1.0\n");
+  }
+  else {
+    strcat(defines, "#define DFDX_SIGN -1.0\n");
+  }
+
+  if (derivatives_factors[1] == 1.0f) {
+    strcat(defines, "#define DFDY_SIGN 1.0\n");
+  }
+  else {
+    strcat(defines, "#define DFDY_SIGN -1.0\n");
+  }
+
   return;
 }
 
diff --git a/source/blender/gpu/shaders/material/gpu_shader_material_bump.glsl b/source/blender/gpu/shaders/material/gpu_shader_material_bump.glsl
index fabc070b0bc..9f73f654217 100644
--- a/source/blender/gpu/shaders/material/gpu_shader_material_bump.glsl
+++ b/source/blender/gpu/shaders/material/gpu_shader_material_bump.glsl
@@ -1,11 +1,11 @@
 void dfdx_v3(vec3 v, out vec3 dy)
 {
-  dy = v + abs(dFdx(v));
+  dy = v + DFDX_SIGN * dFdx(v);
 }
 
 void dfdy_v3(vec3 v, out vec3 dy)
 {
-  dy = v + abs(dFdy(v));
+  dy = v + DFDY_SIGN * dFdy(v);
 }
 
 void node_bump(float strength,