gl_rasterizer/lighting: use the formula from the paper for germetic factor

This commit is contained in:
wwylele 2017-06-18 10:17:12 +03:00
parent 7052d43a67
commit 5a454173a8

View File

@ -521,6 +521,7 @@ static void WriteLighting(std::string& out, const PicaShaderConfig& config) {
"vec3 light_vector = vec3(0.0);\n"
"vec3 refl_value = vec3(0.0);\n"
"vec3 spot_dir = vec3(0.0);\n"
"vec3 half_vector = vec3(0.0);\n"
"float geo_factor = 1.0;\n";
// Compute fragment normals and tangents
@ -564,15 +565,14 @@ static void WriteLighting(std::string& out, const PicaShaderConfig& config) {
// Gets the index into the specified lookup table for specular lighting
auto GetLutIndex = [&lighting](unsigned light_num, LightingRegs::LightingLutInput input,
bool abs) {
const std::string half_angle = "normalize(normalize(view) + light_vector)";
std::string index;
switch (input) {
case LightingRegs::LightingLutInput::NH:
index = "dot(normal, " + half_angle + ")";
index = "dot(normal, normalize(half_vector))";
break;
case LightingRegs::LightingLutInput::VH:
index = std::string("dot(normalize(view), " + half_angle + ")");
index = std::string("dot(normalize(view), normalize(half_vector))");
break;
case LightingRegs::LightingLutInput::NV:
@ -593,9 +593,8 @@ static void WriteLighting(std::string& out, const PicaShaderConfig& config) {
// Note: even if the normal vector is modified by normal map, which is not the
// normal of the tangent plane anymore, the half angle vector is still projected
// using the modified normal vector.
std::string half_angle_proj = half_angle +
" - normal / dot(normal, normal) * dot(normal, " +
half_angle + ")";
std::string half_angle_proj = "normalize(half_vector) - normal / dot(normal, "
"normal) * dot(normal, normalize(half_vector))";
// Note: the half angle vector projection is confirmed not normalized before the dot
// product. The result is in fact not cos(phi) as the name suggested.
index = "dot(" + half_angle_proj + ", tangent)";
@ -641,6 +640,7 @@ static void WriteLighting(std::string& out, const PicaShaderConfig& config) {
out += "light_vector = normalize(" + light_src + ".position + view);\n";
out += "spot_dir = " + light_src + ".spot_direction;\n";
out += "half_vector = normalize(view) + light_vector;\n";
// Compute dot product of light_vector and normal, adjust if lighting is one-sided or
// two-sided
@ -675,8 +675,8 @@ static void WriteLighting(std::string& out, const PicaShaderConfig& config) {
lighting.clamp_highlights ? "(dot(light_vector, normal) <= 0.0 ? 0.0 : 1.0)" : "1.0";
if (light_config.geometric_factor_0 || light_config.geometric_factor_1) {
out += "geo_factor = 1 + dot(light_vector, normalize(view));\n"
"geo_factor = geo_factor == 0.0 ? 0.0 : min(0.5 * " +
out += "geo_factor = dot(half_vector, half_vector);\n"
"geo_factor = geo_factor == 0.0 ? 0.0 : min(" +
dot_product + " / geo_factor, 1.0);\n";
}