From 76f303538b8fd5c4bed1f5878058fb4c18fb045f Mon Sep 17 00:00:00 2001 From: bunnei 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 8bc8e2b362..10cb2d0652 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) {