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Merge pull request #2762 from wwylele/light-cp-tangent

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Fragment lighting: implement lut input 5 (CP) and tangent mapping
This commit is contained in:
Yuri Kunde Schlesner 2017-06-14 20:08:26 -07:00 committed by GitHub
commit da1bec121a
2 changed files with 39 additions and 11 deletions
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2
src/video_core/regs_lighting.h
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@ -84,7 +84,7 @@ struct LightingRegs {
NV = 2, // Cosine of the angle between the normal and the view vector
LN = 3, // Cosine of the angle between the light and the normal vectors
SP = 4, // Cosine of the angle between the light and the inverse spotlight vectors
CP = 5, // TODO: document and implement
CP = 5, // Cosine of the angle between the tangent and projection of half-angle vectors
};
enum class LightingBumpMode : u32 {

48
src/video_core/renderer_opengl/gl_shader_gen.cpp
View file

@ -520,12 +520,12 @@ static void WriteLighting(std::string& out, const PicaShaderConfig& config) {
"vec3 refl_value = vec3(0.0);\n"
"vec3 spot_dir = vec3(0.0);\n;";
// Compute fragment normals
// Compute fragment normals and tangents
const std::string pertubation =
"2.0 * (" + SampleTexture(config, lighting.bump_selector) + ").rgb - 1.0";
if (lighting.bump_mode == LightingRegs::LightingBumpMode::NormalMap) {
// Bump mapping is enabled using a normal map, read perturbation vector from the selected
// texture
out += "vec3 surface_normal = 2.0 * (" + SampleTexture(config, lighting.bump_selector) +
").rgb - 1.0;\n";
// Bump mapping is enabled using a normal map
out += "vec3 surface_normal = " + pertubation + ";\n";
// Recompute Z-component of perturbation if 'renorm' is enabled, this provides a higher
// precision result
@ -534,18 +534,29 @@ static void WriteLighting(std::string& out, const PicaShaderConfig& config) {
"(1.0 - (surface_normal.x*surface_normal.x + surface_normal.y*surface_normal.y))";
out += "surface_normal.z = sqrt(max(" + val + ", 0.0));\n";
}
// The tangent vector is not perturbed by the normal map and is just a unit vector.
out += "vec3 surface_tangent = vec3(1.0, 0.0, 0.0);\n";
} else if (lighting.bump_mode == LightingRegs::LightingBumpMode::TangentMap) {
// Bump mapping is enabled using a tangent map
LOG_CRITICAL(HW_GPU, "unimplemented bump mapping mode (tangent mapping)");
UNIMPLEMENTED();
} else {
// No bump mapping - surface local normal is just a unit normal
out += "vec3 surface_tangent = " + pertubation + ";\n";
// Mathematically, recomputing Z-component of the tangent vector won't affect the relevant
// computation below, which is also confirmed on 3DS. So we don't bother recomputing here
// even if 'renorm' is enabled.
// The normal vector is not perturbed by the tangent map and is just a unit vector.
out += "vec3 surface_normal = vec3(0.0, 0.0, 1.0);\n";
} else {
// No bump mapping - surface local normal and tangent are just unit vectors
out += "vec3 surface_normal = vec3(0.0, 0.0, 1.0);\n";
out += "vec3 surface_tangent = vec3(1.0, 0.0, 0.0);\n";
}
// Rotate the surface-local normal by the interpolated normal quaternion to convert it to
// eyespace.
out += "vec3 normal = quaternion_rotate(normalize(normquat), surface_normal);\n";
out += "vec4 normalized_normquat = normalize(normquat);\n";
out += "vec3 normal = quaternion_rotate(normalized_normquat, surface_normal);\n";
out += "vec3 tangent = quaternion_rotate(normalized_normquat, surface_tangent);\n";
// Gets the index into the specified lookup table for specular lighting
auto GetLutIndex = [&lighting](unsigned light_num, LightingRegs::LightingLutInput input,
@ -573,6 +584,23 @@ static void WriteLighting(std::string& out, const PicaShaderConfig& config) {
index = std::string("dot(light_vector, spot_dir)");
break;
case LightingRegs::LightingLutInput::CP:
// CP input is only available with configuration 7
if (lighting.config == LightingRegs::LightingConfig::Config7) {
// 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 + ")";
// 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)";
} else {
index = "0.0";
}
break;
default:
LOG_CRITICAL(HW_GPU, "Unknown lighting LUT input %d\n", (int)input);
UNIMPLEMENTED();