// Copyright 2015 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include "video_core/pica.h"
#include "video_core/renderer_opengl/gl_rasterizer.h"
#include "video_core/renderer_opengl/gl_shader_gen.h"
using Pica::Regs;
using TevStageConfig = Regs::TevStageConfig;
namespace GLShader {
/// Detects if a TEV stage is configured to be skipped (to avoid generating unnecessary code)
static bool IsPassThroughTevStage(const TevStageConfig& stage) {
return (stage.color_op == TevStageConfig::Operation::Replace &&
stage.alpha_op == TevStageConfig::Operation::Replace &&
stage.color_source1 == TevStageConfig::Source::Previous &&
stage.alpha_source1 == TevStageConfig::Source::Previous &&
stage.color_modifier1 == TevStageConfig::ColorModifier::SourceColor &&
stage.alpha_modifier1 == TevStageConfig::AlphaModifier::SourceAlpha &&
stage.GetColorMultiplier() == 1 &&
stage.GetAlphaMultiplier() == 1);
}
/// Writes the specified TEV stage source component(s)
static void AppendSource(std::string& out, TevStageConfig::Source source,
const std::string& index_name) {
using Source = TevStageConfig::Source;
switch (source) {
case Source::PrimaryColor:
out += "o[2]";
break;
case Source::PrimaryFragmentColor:
// HACK: Until we implement fragment lighting, use primary_color
out += "o[2]";
break;
case Source::SecondaryFragmentColor:
// HACK: Until we implement fragment lighting, use zero
out += "vec4(0.0, 0.0, 0.0, 0.0)";
break;
case Source::Texture0:
out += "texture(tex[0], o[3].xy)";
break;
case Source::Texture1:
out += "texture(tex[1], o[3].zw)";
break;
case Source::Texture2: // TODO: Unverified
out += "texture(tex[2], o[5].zw)";
break;
case Source::PreviousBuffer:
out += "g_combiner_buffer";
break;
case Source::Constant:
out += "const_color[" + index_name + "]";
break;
case Source::Previous:
out += "g_last_tex_env_out";
break;
default:
out += "vec4(0.0)";
LOG_CRITICAL(Render_OpenGL, "Unknown source op %u", source);
break;
}
}
/// Writes the color components to use for the specified TEV stage color modifier
static void AppendColorModifier(std::string& out, TevStageConfig::ColorModifier modifier,
TevStageConfig::Source source, const std::string& index_name) {
using ColorModifier = TevStageConfig::ColorModifier;
switch (modifier) {
case ColorModifier::SourceColor:
AppendSource(out, source, index_name);
out += ".rgb";
break;
case ColorModifier::OneMinusSourceColor:
out += "vec3(1.0) - ";
AppendSource(out, source, index_name);
out += ".rgb";
break;
case ColorModifier::SourceAlpha:
AppendSource(out, source, index_name);
out += ".aaa";
break;
case ColorModifier::OneMinusSourceAlpha:
out += "vec3(1.0) - ";
AppendSource(out, source, index_name);
out += ".aaa";
break;
case ColorModifier::SourceRed:
AppendSource(out, source, index_name);
out += ".rrr";
break;
case ColorModifier::OneMinusSourceRed:
out += "vec3(1.0) - ";
AppendSource(out, source, index_name);
out += ".rrr";
break;
case ColorModifier::SourceGreen:
AppendSource(out, source, index_name);
out += ".ggg";
break;
case ColorModifier::OneMinusSourceGreen:
out += "vec3(1.0) - ";
AppendSource(out, source, index_name);
out += ".ggg";
break;
case ColorModifier::SourceBlue:
AppendSource(out, source, index_name);
out += ".bbb";
break;
case ColorModifier::OneMinusSourceBlue:
out += "vec3(1.0) - ";
AppendSource(out, source, index_name);
out += ".bbb";
break;
default:
out += "vec3(0.0)";
LOG_CRITICAL(Render_OpenGL, "Unknown color modifier op %u", modifier);
break;
}
}
/// Writes the alpha component to use for the specified TEV stage alpha modifier
static void AppendAlphaModifier(std::string& out, TevStageConfig::AlphaModifier modifier,
TevStageConfig::Source source, const std::string& index_name) {
using AlphaModifier = TevStageConfig::AlphaModifier;
switch (modifier) {
case AlphaModifier::SourceAlpha:
AppendSource(out, source, index_name);
out += ".a";
break;
case AlphaModifier::OneMinusSourceAlpha:
out += "1.0 - ";
AppendSource(out, source, index_name);
out += ".a";
break;
case AlphaModifier::SourceRed:
AppendSource(out, source, index_name);
out += ".r";
break;
case AlphaModifier::OneMinusSourceRed:
out += "1.0 - ";
AppendSource(out, source, index_name);
out += ".r";
break;
case AlphaModifier::SourceGreen:
AppendSource(out, source, index_name);
out += ".g";
break;
case AlphaModifier::OneMinusSourceGreen:
out += "1.0 - ";
AppendSource(out, source, index_name);
out += ".g";
break;
case AlphaModifier::SourceBlue:
AppendSource(out, source, index_name);
out += ".b";
break;
case AlphaModifier::OneMinusSourceBlue:
out += "1.0 - ";
AppendSource(out, source, index_name);
out += ".b";
break;
default:
out += "vec3(0.0)";
LOG_CRITICAL(Render_OpenGL, "Unknown alpha modifier op %u", modifier);
break;
}
}
/// Writes the combiner function for the color components for the specified TEV stage operation
static void AppendColorCombiner(std::string& out, TevStageConfig::Operation operation,
const std::string& variable_name) {
using Operation = TevStageConfig::Operation;
switch (operation) {
case Operation::Replace:
out += variable_name + "[0]";
break;
case Operation::Modulate:
out += variable_name + "[0] * " + variable_name + "[1]";
break;
case Operation::Add:
out += "min(" + variable_name + "[0] + " + variable_name + "[1], vec3(1.0))";
break;
case Operation::AddSigned:
out += "clamp(" + variable_name + "[0] + " + variable_name + "[1] - vec3(0.5), vec3(0.0), vec3(1.0))";
break;
case Operation::Lerp:
out += variable_name + "[0] * " + variable_name + "[2] + " + variable_name + "[1] * (vec3(1.0) - " + variable_name + "[2])";
break;
case Operation::Subtract:
out += "max(" + variable_name + "[0] - " + variable_name + "[1], vec3(0.0))";
break;
case Operation::MultiplyThenAdd:
out += "min(" + variable_name + "[0] * " + variable_name + "[1] + " + variable_name + "[2], vec3(1.0))";
break;
case Operation::AddThenMultiply:
out += "min(" + variable_name + "[0] + " + variable_name + "[1], vec3(1.0)) * " + variable_name + "[2]";
break;
default:
out += "vec3(0.0)";
LOG_CRITICAL(Render_OpenGL, "Unknown color combiner operation: %u", operation);
break;
}
}
/// Writes the combiner function for the alpha component for the specified TEV stage operation
static void AppendAlphaCombiner(std::string& out, TevStageConfig::Operation operation,
const std::string& variable_name) {
using Operation = TevStageConfig::Operation;
switch (operation) {
case Operation::Replace:
out += variable_name + "[0]";
break;
case Operation::Modulate:
out += variable_name + "[0] * " + variable_name + "[1]";
break;
case Operation::Add:
out += "min(" + variable_name + "[0] + " + variable_name + "[1], 1.0)";
break;
case Operation::AddSigned:
out += "clamp(" + variable_name + "[0] + " + variable_name + "[1] - 0.5, 0.0, 1.0)";
break;
case Operation::Lerp:
out += variable_name + "[0] * " + variable_name + "[2] + " + variable_name + "[1] * (1.0 - " + variable_name + "[2])";
break;
case Operation::Subtract:
out += "max(" + variable_name + "[0] - " + variable_name + "[1], 0.0)";
break;
case Operation::MultiplyThenAdd:
out += "min(" + variable_name + "[0] * " + variable_name + "[1] + " + variable_name + "[2], 1.0)";
break;
case Operation::AddThenMultiply:
out += "min(" + variable_name + "[0] + " + variable_name + "[1], 1.0) * " + variable_name + "[2]";
break;
default:
out += "0.0";
LOG_CRITICAL(Render_OpenGL, "Unknown alpha combiner operation: %u", operation);
break;
}
}
/// Writes the if-statement condition used to evaluate alpha testing
static void AppendAlphaTestCondition(std::string& out, Regs::CompareFunc func) {
using CompareFunc = Regs::CompareFunc;
switch (func) {
case CompareFunc::Never:
out += "true";
break;
case CompareFunc::Always:
out += "false";
break;
case CompareFunc::Equal:
out += "int(g_last_tex_env_out.a * 255.0f) != alphatest_ref";
break;
case CompareFunc::NotEqual:
out += "int(g_last_tex_env_out.a * 255.0f) == alphatest_ref";
break;
case CompareFunc::LessThan:
out += "int(g_last_tex_env_out.a * 255.0f) >= alphatest_ref";
break;
case CompareFunc::LessThanOrEqual:
out += "int(g_last_tex_env_out.a * 255.0f) > alphatest_ref";
break;
case CompareFunc::GreaterThan:
out += "int(g_last_tex_env_out.a * 255.0f) <= alphatest_ref";
break;
case CompareFunc::GreaterThanOrEqual:
out += "int(g_last_tex_env_out.a * 255.0f) < alphatest_ref";
break;
default:
out += "false";
LOG_CRITICAL(Render_OpenGL, "Unknown alpha test condition %u", func);
break;
}
}
/// Writes the code to emulate the specified TEV stage
static void WriteTevStage(std::string& out, const ShaderCacheKey& config, unsigned index) {
auto& stage = config.tev_stages[index];
if (!IsPassThroughTevStage(stage)) {
std::string index_name = std::to_string(index);
out += "vec3 color_results_" + index_name + "[3] = vec3[3](";
AppendColorModifier(out, stage.color_modifier1, stage.color_source1, index_name);
out += ", ";
AppendColorModifier(out, stage.color_modifier2, stage.color_source2, index_name);
out += ", ";
AppendColorModifier(out, stage.color_modifier3, stage.color_source3, index_name);
out += ");\n";
out += "vec3 color_output_" + index_name + " = ";
AppendColorCombiner(out, stage.color_op, "color_results_" + index_name);
out += ";\n";
out += "float alpha_results_" + index_name + "[3] = float[3](";
AppendAlphaModifier(out, stage.alpha_modifier1, stage.alpha_source1, index_name);
out += ", ";
AppendAlphaModifier(out, stage.alpha_modifier2, stage.alpha_source2, index_name);
out += ", ";
AppendAlphaModifier(out, stage.alpha_modifier3, stage.alpha_source3, index_name);
out += ");\n";
out += "float alpha_output_" + index_name + " = ";
AppendAlphaCombiner(out, stage.alpha_op, "alpha_results_" + index_name);
out += ";\n";
out += "g_last_tex_env_out = vec4("
"clamp(color_output_" + index_name + " * " + std::to_string(stage.GetColorMultiplier()) + ".0, 0.0, 1.0),"
"clamp(alpha_output_" + index_name + " * " + std::to_string(stage.GetAlphaMultiplier()) + ".0, 0.0, 1.0));\n";
}
if (config.TevStageUpdatesCombinerBufferColor(index))
out += "g_combiner_buffer.rgb = g_last_tex_env_out.rgb;\n";
if (config.TevStageUpdatesCombinerBufferAlpha(index))
out += "g_combiner_buffer.a = g_last_tex_env_out.a;\n";
}
std::string GenerateFragmentShader(const ShaderCacheKey& config) {
std::string out = R"(
#version 150 core
#define NUM_VTX_ATTR 7
#define NUM_TEV_STAGES 6
in vec4 o[NUM_VTX_ATTR];
out vec4 color;
uniform int alphatest_ref;
uniform vec4 const_color[NUM_TEV_STAGES];
uniform sampler2D tex[3];
uniform vec4 tev_combiner_buffer_color;
void main(void) {
vec4 g_combiner_buffer = tev_combiner_buffer_color;
vec4 g_last_tex_env_out = vec4(0.0, 0.0, 0.0, 0.0);
)";
// 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) {
out += "discard;";
return out;
}
for (std::size_t index = 0; index < config.tev_stages.size(); ++index)
WriteTevStage(out, config, (unsigned)index);
if (config.alpha_test_func != Regs::CompareFunc::Always) {
out += "if (";
AppendAlphaTestCondition(out, config.alpha_test_func);
out += ") {\n discard;\n }\n";
}
out += "color = g_last_tex_env_out;\n}";
return out;
}
std::string GenerateVertexShader() {
static const std::string out = R"(
#version 150 core
#define NUM_VTX_ATTR 7
in vec4 vert_position;
in vec4 vert_color;
in vec2 vert_texcoords0;
in vec2 vert_texcoords1;
in vec2 vert_texcoords2;
out vec4 o[NUM_VTX_ATTR];
void main() {
o[2] = vert_color;
o[3] = vec4(vert_texcoords0.xy, vert_texcoords1.xy);
o[5] = vec4(0.0, 0.0, vert_texcoords2.xy);
gl_Position = vec4(vert_position.x, -vert_position.y, -vert_position.z, vert_position.w);
}
)";
return out;
}
} // namespace GLShader
