From 76f303538b8fd5c4bed1f5878058fb4c18fb045f Mon Sep 17 00:00:00 2001
From: bunnei <bunneidev@gmail.com>
Date: Wed, 18 Nov 2015 22:36:01 -0500
Subject: [PATCH] gl_shader_gen: Reorganize and cleanup lighting code.
- No functional difference.
---
.../renderer_opengl/gl_shader_gen.cpp | 207 +++++++++---------
1 file changed, 107 insertions(+), 100 deletions(-)
diff --git a/src/video_core/renderer_opengl/gl_shader_gen.cpp b/src/video_core/renderer_opengl/gl_shader_gen.cpp
index 8bc8e2b36..10cb2d065 100644
--- a/src/video_core/renderer_opengl/gl_shader_gen.cpp
+++ b/src/video_core/renderer_opengl/gl_shader_gen.cpp
@@ -318,6 +318,111 @@ static void WriteTevStage(std::string& out, const PicaShaderConfig& config, unsi
out += "next_combiner_buffer.a = last_tex_env_out.a;\n";
}
+/// Writes the code to emulate fragment lighting
+static void WriteLighting(std::string& out, const PicaShaderConfig& config) {
+ // Define lighting globals
+ out += "vec3 diffuse_sum = vec3(0.0);\n";
+ out += "vec3 specular_sum = vec3(0.0);\n";
+ out += "vec3 light_vector = vec3(0.0);\n";
+
+ // Convert interpolated quaternion to a GL fragment normal
+ out += "vec3 normal = normalize(vec3(\n";
+ out += " 2.f*(normquat.x*normquat.z + normquat.y*normquat.w),\n";
+ out += " 2.f*(normquat.y*normquat.z + normquat.x*normquat.w),\n";
+ out += " 1.f - 2.f*(normquat.x*normquat.x + normquat.y*normquat.y)));\n";
+
+ // Gets the index into the specified lookup table for specular lighting
+ auto GetLutIndex = [config](unsigned light_num, Regs::LightingLutInput input, bool abs) {
+ const std::string half_angle = "normalize(normalize(view) + light_vector)";
+ std::string index;
+ switch (input) {
+ case Regs::LightingLutInput::NH:
+ index = "dot(normal, " + half_angle + ")";
+ break;
+
+ case Regs::LightingLutInput::VH:
+ index = std::string("dot(view, " + half_angle + ")");
+ break;
+
+ case Regs::LightingLutInput::NV:
+ index = std::string("dot(normal, view)");
+ break;
+
+ case Regs::LightingLutInput::LN:
+ index = std::string("dot(light_vector, normal)");
+ break;
+
+ default:
+ LOG_CRITICAL(HW_GPU, "Unknown lighting LUT input %d\n", (int)input);
+ UNIMPLEMENTED();
+ break;
+ }
+
+ if (abs) {
+ // LUT index is in the range of (0.0, 1.0)
+ index = config.light_src[light_num].two_sided_diffuse ? "abs(" + index + ")" : "max(" + index + ", 0.f)";
+ return "clamp(" + index + ", 0.0, FLOAT_255)";
+ } else {
+ // LUT index is in the range of (-1.0, 1.0)
+ index = "clamp(" + index + ", -1.0, 1.0)";
+ return "clamp(((" + index + " < 0) ? " + index + " + 2.0 : " + index + ") / 2.0, 0.0, FLOAT_255)";
+ }
+
+ return std::string();
+ };
+
+ // Gets the lighting lookup table value given the specified sampler and index
+ auto GetLutValue = [](Regs::LightingSampler sampler, std::string lut_index) {
+ return std::string("texture(lut[" + std::to_string((unsigned)sampler / 4) + "], " +
+ lut_index + ")[" + std::to_string((unsigned)sampler & 3) + "]");
+ };
+
+ // Write the code to emulate each enabled light
+ for (unsigned light_index = 0; light_index < config.num_lights; ++light_index) {
+ unsigned num = config.light_src[light_index].num;
+ const auto& light_config = config.light_src[light_index];
+ std::string light_src = "light_src[" + std::to_string(num) + "]";
+
+ // Compute light vector (directional or positional)
+ if (light_config.directional)
+ out += "light_vector = normalize(" + light_src + ".position);\n";
+ else
+ out += "light_vector = normalize(" + light_src + ".position + view);\n";
+
+ // Compute dot product of light_vector and normal, adjust if lighting is one-sided or two-sided
+ std::string dot_product = light_config.two_sided_diffuse ? "abs(dot(light_vector, normal))" : "max(dot(light_vector, normal), 0.0)";
+
+ // If enabled, compute distance attenuation value
+ std::string dist_atten = "1.0";
+ if (light_config.dist_atten_enabled) {
+ std::string scale = std::to_string(light_config.dist_atten_scale);
+ std::string bias = std::to_string(light_config.dist_atten_bias);
+ std::string lut_index = "(" + scale + " * length(-view - " + light_src + ".position) + " + bias + ")";
+ lut_index = "((clamp(" + lut_index + ", 0.0, FLOAT_255)))";
+ const unsigned lut_num = ((unsigned)Regs::LightingSampler::DistanceAttenuation + num);
+ dist_atten = GetLutValue((Regs::LightingSampler)lut_num, lut_index);
+ }
+
+ // Compute primary fragment color (diffuse lighting) function
+ out += "diffuse_sum += ((" + light_src + ".diffuse * " + dot_product + ") + " + light_src + ".ambient) * " + dist_atten + ";\n";
+
+ // If enabled, clamp specular component if lighting result is negative
+ std::string clamp_highlights = config.clamp_highlights ? "(dot(light_vector, normal) <= 0.0 ? 0.0 : 1.0)" : "1.0";
+
+ // Lookup specular distribution 0 LUT value
+ std::string d0_lut_index = GetLutIndex(num, config.lighting_lut.d0_type, config.lighting_lut.d0_abs);
+ std::string d0_lut_value = GetLutValue(Regs::LightingSampler::Distribution0, d0_lut_index);
+
+ // Compute secondary fragment color (specular lighting) function
+ out += "specular_sum += " + clamp_highlights + " * " + d0_lut_value + " * " + light_src + ".specular_0 * " + dist_atten + ";\n";
+ }
+
+ // Sum final lighting result
+ out += "diffuse_sum += lighting_global_ambient;\n";
+ out += "primary_fragment_color = vec4(clamp(diffuse_sum, vec3(0.0), vec3(1.0)), 1.0);\n";
+ out += "secondary_fragment_color = vec4(clamp(specular_sum, vec3(0.0), vec3(1.0)), 1.0);\n";
+}
+
std::string GenerateFragmentShader(const PicaShaderConfig& config) {
std::string out = R"(
#version 330 core
@@ -358,106 +463,8 @@ vec4 primary_fragment_color = vec4(0.0);
vec4 secondary_fragment_color = vec4(0.0);
)";
- if (config.lighting_enabled) {
- out += "vec3 normal = normalize(vec3(\n";
- out += " 2.f*(normquat.x*normquat.z + normquat.y*normquat.w),\n";
- out += " 2.f*(normquat.y*normquat.z + normquat.x*normquat.w),\n";
- out += " 1.f - 2.f*(normquat.x*normquat.x + normquat.y*normquat.y)));\n";
- out += "vec4 secondary_color = vec4(0.0);\n";
- out += "vec3 diffuse_sum = vec3(0.0);\n";
- out += "vec3 specular_sum = vec3(0.0);\n";
- out += "vec3 fragment_position = -view;\n";
- out += "vec3 light_vector = vec3(0.0);\n";
- out += "vec3 half_angle_vector = vec3(0.0);\n";
- out += "float clamp_highlights = 1.0;\n";
- out += "float dist_atten = 1.0;\n";
-
- // Gets the index into the specified lookup table for specular lighting
- auto GetLutIndex = [&](unsigned light_num, Regs::LightingLutInput input, bool abs) {
- std::string index;
- switch (input) {
- case Regs::LightingLutInput::NH:
- index = "dot(normal, half_angle_vector)";
- break;
-
- case Regs::LightingLutInput::VH:
- index = std::string("dot(view, half_angle_vector)");
- break;
-
- case Regs::LightingLutInput::NV:
- index = std::string("dot(normal, view)");
- break;
-
- case Regs::LightingLutInput::LN:
- index = std::string("dot(light_vector, normal)");
- break;
-
- default:
- LOG_CRITICAL(HW_GPU, "Unknown lighting LUT input %d\n", (int)input);
- UNIMPLEMENTED();
- break;
- }
-
- if (abs) {
- // In the range of [ 0.f, 1.f]
- index = config.light_src[light_num].two_sided_diffuse ? "abs(" + index + ")" : "max(" + index + ", 0.f)";
- return "clamp(" + index + ", 0.0, FLOAT_255)";
- } else {
- // In the range of [-1.f, 1.f]
- index = "clamp(" + index + ", -1.0, 1.0)";
- return "clamp(((" + index + " < 0) ? " + index + " + 2.0 : " + index + ") / 2.0, 0.0, FLOAT_255)";
- }
-
- return std::string();
- };
-
- for (unsigned light_index = 0; light_index < config.num_lights; ++light_index) {
- unsigned num = config.light_src[light_index].num;
- std::string light_src = "light_src[" + std::to_string(num) + "]";
-
- if (config.light_src[light_index].directional)
- out += "light_vector = normalize(" + light_src + ".position);\n";
- else
- out += "light_vector = normalize(" + light_src + ".position - fragment_position);\n";
-
- std::string dot_product;
- if (config.light_src[light_index].two_sided_diffuse)
- dot_product = "abs(dot(light_vector, normal))";
- else
- dot_product = "max(dot(light_vector, normal), 0.0)";
-
- // Compute distance attenuation value
- out += "dist_atten = 1.0;\n";
- if (config.light_src[light_index].dist_atten_enabled) {
- std::string scale = std::to_string(config.light_src[light_index].dist_atten_scale);
- std::string bias = std::to_string(config.light_src[light_index].dist_atten_bias);
- std::string lut_index = "(" + scale + " * length(fragment_position - " + light_src + ".position) + " + bias + ")";
- std::string clamped_lut_index = "((clamp(" + lut_index + ", 0.0, FLOAT_255)))";
-
- const unsigned lut_num = ((unsigned)Regs::LightingSampler::DistanceAttenuation + num);
- out += "dist_atten = texture(lut[" + std::to_string(lut_num / 4) + "], " + clamped_lut_index + ")[" + std::to_string(lut_num & 3) + "];\n";
- }
-
- // Compute primary fragment color (diffuse lighting) function
- out += "diffuse_sum += ((light_src[" + std::to_string(num) + "].diffuse * " + dot_product + ") + light_src[" + std::to_string(num) + "].ambient) * dist_atten;\n";
-
- // Compute secondary fragment color (specular lighting) function
- out += "half_angle_vector = normalize(normalize(view) + light_vector);\n";
- std::string clamped_lut_index = GetLutIndex(num, config.lighting_lut.d0_type, config.lighting_lut.d0_abs);
- const unsigned lut_num = (unsigned)Regs::LightingSampler::Distribution0;
- std::string lut_lookup = "texture(lut[" + std::to_string(lut_num / 4) + "], " + clamped_lut_index + ")[" + std::to_string(lut_num & 3) + "]";
-
- if (config.clamp_highlights) {
- out += "clamp_highlights = (dot(light_vector, normal) <= 0.0) ? 0.0 : 1.0;\n";
- }
-
- out += "specular_sum += clamp_highlights * " + lut_lookup + " * light_src[" + std::to_string(num) + "].specular_0 * dist_atten;\n";
- }
-
- out += "diffuse_sum += lighting_global_ambient;\n";
- out += "primary_fragment_color = vec4(clamp(diffuse_sum, vec3(0.0), vec3(1.0)), 1.0);\n";
- out += "secondary_fragment_color = vec4(clamp(specular_sum, vec3(0.0), vec3(1.0)), 1.0);\n";
- }
+ if (config.lighting_enabled)
+ WriteLighting(out, config);
// Do not do any sort of processing if it's obvious we're not going to pass the alpha test
if (config.alpha_test_func == Regs::CompareFunc::Never) {