Fix multiple point light shadows on Vulkan

Light locations had to be padded properly, that ended up being the ultimate fix. Leading to this bug though I ended up patching a lot of stuff that was mysteriously missing from the Vulkan backend like specialization constants and

engine/renderer/include/shadowpass.hpp

@@ -45,7 +45,7 @@ private:
     GFXFramebuffer* offscreen_framebuffer = nullptr;
 
     GFXBuffer* point_location_buffer = nullptr;
-    prism::float3* point_location_map = nullptr;
+    prism::float4* point_location_map = nullptr;
     
     // sun
     GFXPipeline* static_sun_pipeline = nullptr;

engine/renderer/src/renderer.cpp

@@ -372,7 +372,8 @@ void renderer::render_camera(GFXCommandBuffer* command_buffer, Scene& scene, Obj
     sceneInfo.camPos = scene.get<Transform>(camera_object).get_world_position();
     sceneInfo.camPos.w = 2.0f * camera.near * std::tan(camera.fov * 0.5f) * (static_cast<float>(extent.width) / static_cast<float>(extent.height));
     sceneInfo.vp =  camera.perspective * camera.view;
-    
+
+    int last_point_light = 0;
     for(const auto& [obj, light] : scene.get_all<Light>()) {
         SceneLight sl;
         sl.positionType = prism::float4(scene.get<Transform>(obj).get_world_position(), static_cast<float>(light.type));
@@ -381,8 +382,12 @@ void renderer::render_camera(GFXCommandBuffer* command_buffer, Scene& scene, Obj
         
         sl.directionPower = prism::float4(-front, light.power);
         sl.colorSize = prism::float4(utility::from_srgb_to_linear(light.color), radians(light.spot_size));
-        sl.shadowsEnable = prism::float4(light.enable_shadows, radians(light.size), 0, 0);
+
-        
+        sl.shadowsEnable = prism::float4(light.enable_shadows, radians(light.size), last_point_light, 0);
+
+        if(light.enable_shadows)
+            last_point_light++;
+
         sceneInfo.lights[sceneInfo.numLights++] = sl;
     }
     

engine/renderer/src/shadowpass.cpp

@@ -141,7 +141,7 @@ void ShadowPass::render_meshes(GFXCommandBuffer* command_buffer, Scene& scene, c
                     break;
             }
             
-            command_buffer->bind_shader_buffer(point_location_buffer, 0, 2, sizeof(prism::float3) * max_point_shadows);
+            command_buffer->bind_shader_buffer(point_location_buffer, 0, 2, sizeof(prism::float4) * max_point_shadows);
 
             command_buffer->set_push_constant(&pc, sizeof(PushConstant));
             command_buffer->set_depth_bias(1.25f, 0.00f, 1.75f);
@@ -165,7 +165,7 @@ void ShadowPass::render_meshes(GFXCommandBuffer* command_buffer, Scene& scene, c
                     break;
             }
 
-            command_buffer->bind_shader_buffer(point_location_buffer, 0, 2, sizeof(prism::float3) * max_point_shadows);
+            command_buffer->bind_shader_buffer(point_location_buffer, 0, 2, sizeof(prism::float4) * max_point_shadows);
             
             command_buffer->set_push_constant(&pc, sizeof(PushConstant));
             
@@ -266,7 +266,9 @@ void ShadowPass::render_point(GFXCommandBuffer* command_buffer, Scene& scene, Ob
         return;
     
     if(scene.point_light_dirty[last_point_light] || light.use_dynamic_shadows) {
-        *(point_location_map + last_point_light) = scene.get<Transform>(light_object).get_world_position();
+        const prism::float3 lightPos = scene.get<Transform>(light_object).get_world_position();
+
+        (point_location_map + last_point_light)->xyz = lightPos;
 
         for(int face = 0; face < 6; face++) {
             GFXRenderPassBeginInfo info = {};
@@ -281,9 +283,7 @@ void ShadowPass::render_point(GFXCommandBuffer* command_buffer, Scene& scene, Ob
             viewport.height = render_options.shadow_resolution;
             
             command_buffer->set_viewport(viewport);
-            
+
-            const prism::float3 lightPos = scene.get<Transform>(light_object).get_world_position();
-            
             const Matrix4x4 projection = prism::perspective(radians(90.0f), 1.0f, 0.1f, 100.0f);
             const Matrix4x4 model = inverse(scene.get<Transform>(light_object).model);
             
@@ -408,6 +408,6 @@ void ShadowPass::create_offscreen_resources() {
     
     offscreen_framebuffer = gfx->create_framebuffer(info);
 
-    point_location_buffer = gfx->create_buffer(nullptr, sizeof(prism::float3) * max_point_shadows, false, GFXBufferUsage::Storage);
+    point_location_buffer = gfx->create_buffer(nullptr, sizeof(prism::float4) * max_point_shadows, false, GFXBufferUsage::Storage);
-    point_location_map = reinterpret_cast<prism::float3*>(gfx->get_buffer_contents(point_location_buffer));
+    point_location_map = reinterpret_cast<prism::float4*>(gfx->get_buffer_contents(point_location_buffer));
 }

engine/shaders/omnishadow.frag.glsl

@@ -6,9 +6,9 @@ layout (location = 1) flat in int index;
 layout (location = 0) out float outFragColor;
 
 layout(std430, binding = 2) buffer readonly LightInformation {
-    vec3 light_locations[max_lights];
+    vec4 light_locations[max_lights];
 };
 
 void main() {
-    outFragColor = length(inPos - light_locations[index]);
+    outFragColor = length(inPos - light_locations[index].xyz);
 }

engine/shaders/rendering.nocompile.glsl

@@ -269,8 +269,6 @@ float pcss_point(const vec3 shadowCoords, const int index, float light_size_uv)
 
 #endif
 
-int last_point_light = 0;
-
 ComputedLightInformation calculate_point(Light light) {
     ComputedLightInformation light_info;
     light_info.direction = normalize(light.positionType.xyz - in_frag_pos);
@@ -282,16 +280,16 @@ ComputedLightInformation calculate_point(Light light) {
 #ifdef POINT_SHADOWS_SUPPORTED
     if(light.shadowsEnable.x == 1.0) {
 #ifdef SHADOW_FILTER_NONE
-        const float sampledDist = texture(point_shadow, vec4(lightVec, last_point_light++)).r;
+        const float sampledDist = texture(point_shadow, vec4(lightVec, int(light.shadowsEnable.z))).r;
         const float dist = length(lightVec);
         
         shadow = (dist <= sampledDist + 0.05) ? 1.0 : 0.0;
 #endif
 #ifdef SHADOW_FILTER_PCF
-        shadow = pcf_point(lightVec, last_point_light++, 1.0);
+        shadow = pcf_point(lightVec, int(light.shadowsEnable.z), 1.0);
 #endif
 #ifdef SHADOW_FILTER_PCSS
-        shadow = pcss_point(lightVec, last_point_light++, light.shadowsEnable.y);
+        shadow = pcss_point(lightVec, int(light.shadowsEnable.z), light.shadowsEnable.y);
 #endif
     }
 #endif

engine/shaders/shadow.vert.nocompile.glsl

@@ -21,7 +21,7 @@ layout(std430, binding = 14) buffer readonly BoneInformation {
 #endif
 
 layout(std430, binding = 2) buffer readonly LightInformation {
-    vec3 light_locations[max_lights];
+    vec4 light_locations[max_lights];
 };
 
 void main() {
@@ -36,7 +36,7 @@ void main() {
     gl_Position = mvp * BoneTransform * vec4(inPosition, 1.0);
     outPos = vec3(model * vec4(inPosition, 1.0));
 #else
-    gl_Position =  mvp * vec4(inPosition, 1.0);
+    gl_Position = mvp * vec4(inPosition, 1.0);
     outPos = vec3(model * vec4(inPosition, 1.0));    
 #endif
     index = gl_BaseInstance;