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phong lighting model #140

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8899ca9
phong
qwertyquerty Apr 26, 2026
ecc4491
Merge branch 'main' into phong
qwertyquerty Apr 30, 2026
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16 changes: 16 additions & 0 deletions include/aurora/gfx.h
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Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,22 @@ const AuroraStats* aurora_get_stats();

void aurora_enable_vsync(bool enabled);

void aurora_set_enhanced_lighting(bool enabled);
bool aurora_get_enhanced_lighting();

void aurora_set_specular_lighting(bool enabled);
bool aurora_get_specular_lighting();
void aurora_set_rim_lighting(bool enabled);
bool aurora_get_rim_lighting();
void aurora_set_specular_intensity(float intensity);
float aurora_get_specular_intensity();
void aurora_set_rim_intensity(float intensity);
float aurora_get_rim_intensity();
void aurora_set_ambient_multiplier(float multiplier);
float aurora_get_ambient_multiplier();
void aurora_set_diffuse_multiplier(float multiplier);
float aurora_get_diffuse_multiplier();
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@encounter encounter May 6, 2026

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The public API looks kind of awkward, I think. Would it make sense to pass these all in at once? EnhancedLightingState or something?


#ifdef __cplusplus
}
#endif
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16 changes: 16 additions & 0 deletions lib/gfx/common.cpp
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Expand Up @@ -1058,3 +1058,19 @@ void pop_debug_group() {
}

const AuroraStats* aurora_get_stats() { return &aurora::gfx::g_stats; }

void aurora_set_enhanced_lighting(const bool enabled) { aurora::gx::g_enhancedLighting = enabled; }
bool aurora_get_enhanced_lighting() { return aurora::gx::g_enhancedLighting; }

void aurora_set_specular_lighting(const bool enabled) { aurora::gx::g_enableSpecular = enabled; }
bool aurora_get_specular_lighting() { return aurora::gx::g_enableSpecular; }
void aurora_set_rim_lighting(const bool enabled) { aurora::gx::g_enableRim = enabled; }
bool aurora_get_rim_lighting() { return aurora::gx::g_enableRim; }
void aurora_set_specular_intensity(const float intensity) { aurora::gx::g_specularIntensity = intensity; }
float aurora_get_specular_intensity() { return aurora::gx::g_specularIntensity; }
void aurora_set_rim_intensity(const float intensity) { aurora::gx::g_rimIntensity = intensity; }
float aurora_get_rim_intensity() { return aurora::gx::g_rimIntensity; }
void aurora_set_ambient_multiplier(const float multiplier) { aurora::gx::g_ambientMultiplier = multiplier; }
float aurora_get_ambient_multiplier() { return aurora::gx::g_ambientMultiplier; }
void aurora_set_diffuse_multiplier(const float multiplier) { aurora::gx::g_diffuseMultiplier = multiplier; }
float aurora_get_diffuse_multiplier() { return aurora::gx::g_diffuseMultiplier; }
11 changes: 11 additions & 0 deletions lib/gx/gx.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -724,6 +724,14 @@ u8 comp_cnt_count(GXAttr attr, GXCompCnt cnt) noexcept {
Log.fatal("comp_cnt_count: Unsupported attr/cnt {} {}", attr, cnt);
}

bool g_enhancedLighting = true;
bool g_enableSpecular = true;
bool g_enableRim = true;
float g_specularIntensity = 0.2f;
float g_rimIntensity = 0.08f;
float g_ambientMultiplier = 1.0f;
float g_diffuseMultiplier = 1.0f;

void populate_pipeline_config(PipelineConfig& config, GXPrimitive primitive, GXVtxFmt fmt) noexcept {
ZoneScoped;

Expand Down Expand Up @@ -787,6 +795,9 @@ void populate_pipeline_config(PipelineConfig& config, GXPrimitive primitive, GXV
config.shaderConfig.indStages[i] = g_gxState.indStages[i];
}
config.shaderConfig.numIndStages = g_gxState.numIndStages;
config.shaderConfig.enhancedLighting = g_enhancedLighting ? 1 : 0;
config.shaderConfig.enableSpecular = g_enableSpecular ? 1 : 0;
config.shaderConfig.enableRim = g_enableRim ? 1 : 0;
for (u8 i = 0; i < MaxColorChannels; ++i) {
const auto& cc = g_gxState.colorChannelConfig[i];
if (cc.lightingEnabled) {
Expand Down
15 changes: 13 additions & 2 deletions lib/gx/gx.hpp
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Expand Up @@ -47,7 +47,7 @@ constexpr float GX_LARGE_NUMBER = -1048576.0f;
namespace aurora::gx {
constexpr bool EnableNormalVisualization = false;
constexpr bool EnableDebugPrints = false;
constexpr bool UsePerPixelLighting = false;
constexpr bool UsePerPixelLighting = true;
constexpr bool UseReversedZ = true;

constexpr u32 MaxTextures = GX_MAX_TEXMAP;
Expand Down Expand Up @@ -383,6 +383,13 @@ struct GXState {
void clearVtxSizeCache() { lastVtxFmt = GX_MAX_VTXFMT; }
};
extern GXState g_gxState;
extern bool g_enhancedLighting;
extern bool g_enableSpecular;
extern bool g_enableRim;
extern float g_specularIntensity;
extern float g_rimIntensity;
extern float g_ambientMultiplier;
extern float g_diffuseMultiplier;
Comment on lines +386 to +392
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@encounter encounter May 6, 2026 •
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Might be best to wrap these in a struct of some kind. maybe ExtState (or reuse EnhancedLightingState if it makes sense)

struct ShaderInfo;

void initialize() noexcept;
Expand Down Expand Up @@ -439,7 +446,10 @@ struct ShaderConfig {
u8 fogType = GX_FOG_NONE;
u8 vtxStride = 0;
u8 lineMode : 2 = 0; // 1 = GX_LINES, 2 = GX_LINESTRIP, 3 = GX_POINTS
u8 pad1 : 6 = 0;
u8 enhancedLighting : 1 = 1;
u8 enableSpecular : 1 = 1;
u8 enableRim : 1 = 1;
u8 pad1 : 3 = 0;
u8 pad2 = 0;
std::array<AttrConfig, MaxVtxAttr> attrs;
std::array<TevSwap, MaxTevSwap> tevSwapTable;
Expand Down Expand Up @@ -476,6 +486,7 @@ struct ShaderInfo {
u32 uniformSize = 0;
bool usesFog : 1 = false;
bool lightingEnabled : 1 = false;
bool enhancedLighting : 1 = false;
u8 lineMode : 2 = 0;
};
struct BindGroupRanges {
Expand Down
61 changes: 48 additions & 13 deletions lib/gx/shader.cpp
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Expand Up @@ -592,7 +592,7 @@ auto lighting_func(const ShaderConfig& config, const ColorChannelConfig& cc, u8
std::string_view swizzle = alpha ? ".a"sv : ""sv;
std::string outVar;
std::string_view posVar;
if (UsePerPixelLighting) {
if (config.enhancedLighting) {
outVar = fmt::format("rast{}", i);
posVar = "in.mv_pos"sv;
} else {
Expand All @@ -601,7 +601,7 @@ auto lighting_func(const ShaderConfig& config, const ColorChannelConfig& cc, u8
}
std::string ambSrc, matSrc;
if (cc.ambSrc == GX_SRC_VTX) {
if (UsePerPixelLighting) {
if (config.enhancedLighting) {
ambSrc = fmt::format("in.clr{}", i);
} else {
ambSrc = vtx_attr(config, static_cast<GXAttr>(GX_VA_CLR0 + i));
Expand All @@ -610,7 +610,7 @@ auto lighting_func(const ShaderConfig& config, const ColorChannelConfig& cc, u8
ambSrc = fmt::format("ubuf.cc{0}{1}_amb", i, alpha ? "a"sv : ""sv);
}
if (cc.matSrc == GX_SRC_VTX) {
if (UsePerPixelLighting) {
if (config.enhancedLighting) {
matSrc = fmt::format("in.clr{}", i);
} else {
matSrc = vtx_attr(config, static_cast<GXAttr>(GX_VA_CLR0 + i));
Expand All @@ -632,7 +632,7 @@ auto lighting_func(const ShaderConfig& config, const ColorChannelConfig& cc, u8
var dist_attn = dot(light.dist_att, vec3f(1.0, dist, dist2));
attn = max(0.0, cos_attn / dist_attn);)""");
} else if (cc.attnFn == GX_AF_SPEC) {
std::string_view normal = UsePerPixelLighting ? "in.mv_nrm"sv : "mv_nrm"sv;
std::string_view normal = config.enhancedLighting ? "in.mv_nrm"sv : "mv_nrm"sv;
std::string dist_attn = diffFn != GX_DF_NONE
? "max(0.0, dot(normalize(light.dist_att), vec3f(1.0, attn, attn * attn)));"
: "max(0.0, dot(light.dist_att, vec3f(1.0, attn, attn * attn)));";
Expand All @@ -647,21 +647,49 @@ auto lighting_func(const ShaderConfig& config, const ColorChannelConfig& cc, u8
if (diffFn == GX_DF_NONE) {
lightDiffFn = "1.0"sv;
} else if (diffFn == GX_DF_SIGN) {
if (UsePerPixelLighting) {
if (config.enhancedLighting) {
lightDiffFn = "dot(ldir, in.mv_nrm)"sv;
} else {
lightDiffFn = "dot(ldir, mv_nrm)"sv;
}
} else if (diffFn == GX_DF_CLAMP) {
if (UsePerPixelLighting) {
if (config.enhancedLighting) {
lightDiffFn = "max(0.0, dot(ldir, in.mv_nrm))"sv;
} else {
lightDiffFn = "max(0.0, dot(ldir, mv_nrm))"sv;
}
}
// Blinn-Phong specular + rim lighting for per-pixel lighting
// Skips GX_AF_SPEC (which already computes specular in a worse way)
std::string ambientScale;
std::string diffuseScale;
std::string viewDirCode;
std::string specularCode;
std::string postLoopCode;
if (config.enhancedLighting) {
ambientScale = " * ubuf.ambient_multiplier";
diffuseScale = " * ubuf.diffuse_multiplier";
if (!alpha && diffFn != GX_DF_NONE && cc.attnFn != GX_AF_SPEC &&
(config.enableSpecular || config.enableRim)) {
viewDirCode = R"""(
let view_dir = normalize(-in.mv_pos);)""";
if (config.enableSpecular) {
specularCode = R"""(
if (diff > 0.0) {
let h = normalize(ldir + view_dir);
spec_contrib = pow(max(0.0, dot(in.mv_nrm, h)), 32.0) * ubuf.specular_intensity;
})""";
}
if (config.enableRim) {
postLoopCode = R"""(
let rim = pow(1.0 - max(0.0, dot(view_dir, in.mv_nrm)), 3.0) * ubuf.rim_intensity;
lighting = lighting + vec4f(rim, rim, rim, 0.0);)""";
}
}
}
return fmt::format(R"""(
{{
var lighting = {5};
var lighting = {5}{13};{11}
for (var i = 0u; i < {1}u; i++) {{
if ((ubuf.lightState{0}{9} & (1u << i)) == 0u) {{ continue; }}
var light = ubuf.lights[i];
Expand All @@ -671,12 +699,13 @@ auto lighting_func(const ShaderConfig& config, const ColorChannelConfig& cc, u8
ldir = ldir / dist;
var attn: f32;{2}
var diff = {3};
lighting = lighting + (attn * diff * light.color);
}}
var spec_contrib: f32 = 0.0;{10}
lighting = lighting + (attn * (diff{14} + spec_contrib) * light.color);
}}{12}
{7}{8} = ({4} * clamp(lighting, vec4f(0.0), vec4f(1.0))){8};
}})""",
i, GX::MaxLights, lightAttnFn, lightDiffFn, matSrc, ambSrc, posVar, outVar, swizzle,
alpha ? "a"sv : ""sv);
alpha ? "a"sv : ""sv, specularCode, viewDirCode, postLoopCode, ambientScale, diffuseScale);
}

wgpu::ShaderModule build_shader(const ShaderConfig& config) noexcept {
Expand Down Expand Up @@ -927,6 +956,12 @@ wgpu::ShaderModule build_shader(const ShaderConfig& config) noexcept {
lightState0a: u32,
lightState1a: u32,)"""),
GX::MaxLights);
if (config.enhancedLighting) {
uniBufAttrs += "\n specular_intensity: f32,";
uniBufAttrs += "\n rim_intensity: f32,";
uniBufAttrs += "\n ambient_multiplier: f32,";
uniBufAttrs += "\n diffuse_multiplier: f32,";
}
uniformPre +=
"\n"
"struct Light {\n"
Expand All @@ -936,7 +971,7 @@ wgpu::ShaderModule build_shader(const ShaderConfig& config) noexcept {
" cos_att: vec3f,\n"
" dist_att: vec3f,\n"
"};";
if (UsePerPixelLighting) {
if (config.enhancedLighting) {
vtxOutAttrs += fmt::format("\n @location({}) mv_pos: vec3f,", vtxOutIdx++);
vtxOutAttrs += fmt::format("\n @location({}) mv_nrm: vec3f,", vtxOutIdx++);
vtxXfrAttrs += fmt::format(FMT_STRING(R"""(
Expand Down Expand Up @@ -966,15 +1001,15 @@ wgpu::ShaderModule build_shader(const ShaderConfig& config) noexcept {
}

// Output vertex color if necessary
if (UsePerPixelLighting) {
if (config.enhancedLighting) {
if ((cc.lightingEnabled && cc.ambSrc == GX_SRC_VTX) || cc.matSrc == GX_SRC_VTX ||
(cca.lightingEnabled && cca.ambSrc == GX_SRC_VTX) || cca.matSrc == GX_SRC_VTX) {
vtxOutAttrs += fmt::format("\n @location({}) clr{}: vec4f,", vtxOutIdx++, i);
vtxXfrAttrs += fmt::format("\n out.clr{} = {};", i, vtx_attr(config, static_cast<GXAttr>(GX_VA_CLR0 + i)));
}
}

if (UsePerPixelLighting) {
if (config.enhancedLighting) {
fragmentFnPre += fmt::format("\n var rast{}: vec4f;", i);
fragmentFnPre += lighting_func(config, cc, i, false);
fragmentFnPre += lighting_func(config, cca, i, true);
Expand Down
11 changes: 11 additions & 0 deletions lib/gx/shader_info.cpp
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Expand Up @@ -265,8 +265,13 @@ ShaderInfo build_shader_info(const ShaderConfig& config) noexcept {
}
}
if (info.lightingEnabled) {
info.enhancedLighting = config.enhancedLighting;
// Lights + light state for all channels
info.uniformSize += 16 + sizeof(Light) * GX::MaxLights;
if (info.enhancedLighting) {
// specular_intensity, rim_intensity, ambient_multiplier, diffuse_multiplier
info.uniformSize += 16;
}
}
for (int i = 0; i < info.sampledColorChannels.size(); ++i) {
if (info.sampledColorChannels.test(i)) {
Expand Down Expand Up @@ -406,6 +411,12 @@ gfx::Range build_uniform(const ShaderInfo& info, u32 vtxStart, const BindGroupRa
for (int i = 0; i < 4; ++i) {
buf.append<u32>(g_gxState.colorChannelState[i].lightMask.to_ulong());
}
if (info.enhancedLighting) {
buf.append<f32>(g_specularIntensity);
buf.append<f32>(g_rimIntensity);
buf.append<f32>(g_ambientMultiplier);
buf.append<f32>(g_diffuseMultiplier);
}
}
for (int i = 0; i < info.sampledColorChannels.size(); ++i) {
if (!info.sampledColorChannels.test(i)) {
Expand Down
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