gl_rasterizer/lighting: Implement tangent mapping

This commit is contained in:
wwylele 2017-06-08 18:48:12 +03:00
parent 40b7d0bf3f
commit 972548e3ee
1 changed files with 12 additions and 7 deletions

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
@ -539,8 +539,13 @@ static void WriteLighting(std::string& out, const PicaShaderConfig& config) {
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();
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";