wip

3 files changed, 29 insertions, 14 deletions

diff --git a/editor/imgui.cpp b/editor/imgui.cpp
index b953a247..c48dbed1 100644
--- a/editor/imgui.cpp
+++ b/editor/imgui.cpp
@@ -218,12 +218,12 @@ void app::draw_lightmap_test()
 
     if (e_ && ImGui::Begin("Lightmap", &is_open, flags))
     {
-        constexpr auto chunk_size = TILE_SIZE2.sum()/2;
+        constexpr auto tile_size = TILE_SIZE2.sum()/2;
         fm_assert(e_->type() == entity_type::light);
         const auto& li = static_cast<const light&>(*e_);
         light_s L {
             .center = Vector2(li.coord.local()) * TILE_SIZE2 + Vector2(li.offset),
-            .dist = li.max_distance * chunk_size,
+            .dist = li.max_distance,
             .color = li.color,
             .falloff = li.falloff,
         };
diff --git a/shaders/lightmap.cpp b/shaders/lightmap.cpp
index 3a2d339a..7fa76d69 100644
--- a/shaders/lightmap.cpp
+++ b/shaders/lightmap.cpp
@@ -109,8 +109,20 @@ void lightmap_shader::add_light(Vector2i neighbor_offset, const light_s& light)
 
     constexpr auto tile_size = TILE_SIZE2.sum()/2;
     constexpr auto scale = 2/chunk_size;
-    auto dist = std::fmax(0.f, light.dist/* * tile_size*/);
-    auto dist_clip = dist/* * tile_size*/;
+    float I;
+    switch (light.falloff)
+    {
+    default:
+        I = 1;
+        break;
+    case light_falloff::linear:
+        I = std::fmax(1.f, light.dist * tile_size);
+        break;
+    case light_falloff::quadratic:
+        I = std::fmax(1.f, light.dist * tile_size * 100);
+        break;
+    }
+    auto I_clip = I * tile_size;
     auto center = light.center + chunk_offset + Vector2(neighbor_offset)*chunk_size;
     auto center_clip = Vector2{center} * scale; // clip coordinate
     constexpr auto image_size_factor = Vector2(image_size) / Vector2(chunk_size);
@@ -118,10 +130,10 @@ void lightmap_shader::add_light(Vector2i neighbor_offset, const light_s& light)
 
     _indexes[_count] = quad_indexes(0);
     _quads[_count] = std::array<Vector2, 4>{{
-        {  dist_clip + center_clip.x(), -dist_clip + center_clip.y() },
-        {  dist_clip + center_clip.x(),  dist_clip + center_clip.y() },
-        { -dist_clip + center_clip.x(), -dist_clip + center_clip.y() },
-        { -dist_clip + center_clip.x(),  dist_clip + center_clip.y() },
+        { I_clip + center_clip.x(), -I_clip + center_clip.y() },
+        { I_clip + center_clip.x(), I_clip + center_clip.y() },
+        { -I_clip + center_clip.x(), -I_clip + center_clip.y() },
+        { -I_clip + center_clip.x(), I_clip + center_clip.y() },
     }};
 
     _count++;
@@ -129,10 +141,10 @@ void lightmap_shader::add_light(Vector2i neighbor_offset, const light_s& light)
     float alpha = light.color.a() / 255.f;
     auto color = Vector3{light.color.rgb()} / 255.f;
 
-    setUniform(ColorIntensityUniform, Vector4{Vector3{color} * alpha, dist});
+    setUniform(ColorIntensityUniform, Vector4{Vector3{color} * alpha, I });
     setUniform(CenterUniform, center_fragcoord);
     setUniform(FalloffUniform, (uint32_t)light.falloff);
-    setUniform(SizeUniform, chunk_size);
+    setUniform(SizeUniform, 1.f/image_size_factor);
 }
 
 lightmap_shader::~lightmap_shader() = default;
diff --git a/shaders/lightmap.frag b/shaders/lightmap.frag
index eb7ed789..75815c0f 100644
--- a/shaders/lightmap.frag
+++ b/shaders/lightmap.frag
@@ -10,9 +10,12 @@ out vec4 color;
 void main() {
     vec2 pos = gl_FragCoord.xy;
     float I = color_intensity.w;
-    vec2 tmp = pos - center;
+    float dist = distance(pos, center);
     //float dist = sqrt(tmp.x*tmp.x + tmp.y*tmp.y);
-    float dist = sqrt(tmp.x*tmp.x + tmp.y*tmp.y);
-    float alpha = 1 - min(1, dist / I);
-    color = vec4(color_intensity.xyz, alpha);
+    float A = 1;
+    if (falloff == 0) // linear
+        A = 1 - min(1, dist / I);
+    else if (falloff == 2) // quadratic
+        A = I/(1 + I + dist*dist);
+    color = vec4(color_intensity.xyz, A);
 }