Use saturated math and explicitly replace multiplication with negative value

diff --git a/shader_glsl.h b/shader_glsl.h
index 10c4347b6a4dbe3922888828311e526ceb123a9f..8f205e0b672e55e8a678d298e4c9142894ef8d26 100644 (file)
--- a/shader_glsl.h
+++ b/shader_glsl.h
@@ -21,19 +21,23 @@
 "# endif\n",
 "#endif\n",
 "\n",
+"#define sat(x) clamp(x, 0, 1)\n",
+"#define possat(x) sat(x)\n",//As replacement of max(x, 0) when x<=1, better for gpus that can't do 0-cycle max(x, 0)
+"#define possatdot(x, y) possat(dot(x, y))\n",
+"\n",
 "#ifdef USECELSHADING\n",
-"# define SHADEDIFFUSE myhalf diffuse = cast_myhalf(min(max(float(dot(surfacenormal, lightnormal)) * 2.0, 0.0), 1.0));\n",
+"# define SHADEDIFFUSE myhalf diffuse = cast_myhalf(sat(float(dot(surfacenormal, lightnormal)) * 2.0));\n",
 "# ifdef USEEXACTSPECULARMATH\n",
-"#  define SHADESPECULAR(specpow) myhalf specular = pow(cast_myhalf(max(float(dot(reflect(lightnormal, surfacenormal), eyenormal))*-1.0, 0.0)), 1.0 + specpow);specular = max(0.0, specular * 10.0 - 9.0);\n",
+"#  define SHADESPECULAR(specpow) myhalf specular = pow(cast_myhalf(float(possatdot(reflect(lightnormal, surfacenormal), -eyenormal))), 1.0 + specpow);specular = possat(specular * 10.0 - 9.0);\n",
 "# else\n",
-"#  define SHADESPECULAR(specpow) myhalf3 specularnormal = normalize(lightnormal + eyenormal);myhalf specular = pow(cast_myhalf(max(float(dot(surfacenormal, specularnormal)), 0.0)), 1.0 + specpow);specular = max(0.0, specular * 10.0 - 9.0);\n",
+"#  define SHADESPECULAR(specpow) myhalf3 specularnormal = normalize(lightnormal + eyenormal);myhalf specular = pow(cast_myhalf(float(possatdot(surfacenormal, specularnormal))), 1.0 + specpow);specular = possat(specular * 10.0 - 9.0);\n",
 "# endif\n",
 "#else\n",
-"# define SHADEDIFFUSE myhalf diffuse = cast_myhalf(max(float(dot(surfacenormal, lightnormal)), 0.0));\n",
+"# define SHADEDIFFUSE myhalf diffuse = cast_myhalf(float(possatdot(surfacenormal, lightnormal)));\n",
 "# ifdef USEEXACTSPECULARMATH\n",
-"#  define SHADESPECULAR(specpow) myhalf specular = pow(cast_myhalf(max(float(dot(reflect(lightnormal, surfacenormal), eyenormal))*-1.0, 0.0)), 1.0 + specpow);\n",
+"#  define SHADESPECULAR(specpow) myhalf specular = pow(cast_myhalf(float(possatdot(reflect(lightnormal, surfacenormal), -eyenormal))), 1.0 + specpow);\n",
 "# else\n",
-"#  define SHADESPECULAR(specpow) myhalf3 specularnormal = normalize(lightnormal + eyenormal);myhalf specular = pow(cast_myhalf(max(float(dot(surfacenormal, specularnormal)), 0.0)), 1.0 + specpow);\n",
+"#  define SHADESPECULAR(specpow) myhalf3 specularnormal = normalize(lightnormal + eyenormal);myhalf specular = pow(cast_myhalf(float(possatdot(surfacenormal, specularnormal))), 1.0 + specpow);\n",
 "# endif\n",
 "#endif\n",
 "\n",