Pass IDs in to shader as integers

asny · Sep 27, 2024 · d5cf6c2 · d5cf6c2
1 parent 8eed6b3
commit d5cf6c2
Show file tree

Hide file tree

Showing 4 changed files with 22 additions and 18 deletions.
diff --git a/src/renderer/geometry/shaders/mesh.vert b/src/renderer/geometry/shaders/mesh.vert
@@ -22,12 +22,12 @@ in vec4 row3;
 
 out vec3 pos;
 
-#ifdef USE_NORMALS 
+#ifdef USE_NORMALS
 uniform mat4 normalMatrix;
 in vec3 normal;
 out vec3 nor;
 
-#ifdef USE_TANGENTS 
+#ifdef USE_TANGENTS
 in vec4 tangent;
 out vec3 tang;
 out vec3 bitang;
@@ -36,7 +36,7 @@ out vec3 bitang;
 #endif
 
 
-#ifdef USE_UVS 
+#ifdef USE_UVS
 #ifdef USE_INSTANCE_TEXTURE_TRANSFORMATION
 in vec3 tex_transform_row1;
 in vec3 tex_transform_row2;
@@ -45,7 +45,7 @@ in vec2 uv_coordinates;
 out vec2 uvs;
 #endif
 
-#ifdef USE_VERTEX_COLORS 
+#ifdef USE_VERTEX_COLORS
 in vec4 color;
 #endif
 #ifdef USE_INSTANCE_COLORS
@@ -54,6 +54,8 @@ in vec4 instance_color;
 
 out vec4 col;
 
+flat out int instanceID;
+
 void main()
 {
     // *** POSITION ***
@@ -73,31 +75,31 @@ void main()
 #ifdef PARTICLES
     worldPosition.xyz += start_position + start_velocity * time + 0.5 * acceleration * time * time;
 #endif
-#ifdef USE_INSTANCE_TRANSLATIONS 
+#ifdef USE_INSTANCE_TRANSLATIONS
     worldPosition.xyz += instance_translation;
 #endif
     gl_Position = viewProjection * worldPosition;
 
     pos = worldPosition.xyz;
 
     // *** NORMAL ***
-#ifdef USE_NORMALS 
+#ifdef USE_NORMALS
 #ifdef USE_INSTANCE_TRANSFORMS
     mat3 normalMat = mat3(transpose(inverse(local2World)));
 #else
     mat3 normalMat = mat3(normalMatrix);
 #endif
     nor = normalize(normalMat * normal);
 
-#ifdef USE_TANGENTS 
+#ifdef USE_TANGENTS
     tang = normalize(normalMat * tangent.xyz);
     bitang = normalize(cross(nor, tang) * tangent.w);
 #endif
 
 #endif
 
     // *** UV ***
-#ifdef USE_UVS 
+#ifdef USE_UVS
 #ifdef USE_INSTANCE_TEXTURE_TRANSFORMATION
     mat3 texTransform;
     texTransform[0] = vec3(tex_transform_row1.x, tex_transform_row2.x, 0.0);
@@ -111,7 +113,7 @@ void main()
 
     // *** COLOR ***
     col = vec4(1.0);
-#ifdef USE_VERTEX_COLORS 
+#ifdef USE_VERTEX_COLORS
     col *= color;
 #endif
 #ifdef USE_INSTANCE_COLORS
@@ -120,6 +122,8 @@ void main()
 
     // *** IDs ***
 #ifdef USE_INSTANCE_ID
-    col.x = -float(gl_InstanceID);
+    instanceID = gl_InstanceID;
+#else
+    instanceID = -1;
 #endif
-}
+}
diff --git a/src/renderer/material.rs b/src/renderer/material.rs
@@ -162,7 +162,7 @@ pub struct FragmentAttributes {
     pub uv: bool,
     /// Color: `in vec4 col;`
     pub color: bool,
-    /// Instance ID: `in uint instanceID`
+    /// Instance ID: `in int instanceID`
     pub instance_id: bool,
 }
 

diff --git a/src/renderer/material/geometry_instance_material.rs b/src/renderer/material/geometry_instance_material.rs
@@ -30,13 +30,14 @@ impl Material for GeometryInstanceMaterial {
 
     fn fragment_attributes(&self) -> FragmentAttributes {
         FragmentAttributes {
+            position: true,
             instance_id: true,
             ..FragmentAttributes::NONE
         }
     }
 
     fn use_uniforms(&self, program: &Program, camera: &Camera, _lights: &[&dyn Light]) {
-        program.use_uniform("id", self.id as f32);
+        program.use_uniform("id", self.id as i32);
         program.use_uniform("eye", camera.position());
     }
 

diff --git a/src/renderer/material/shaders/geometry_instance_material.frag b/src/renderer/material/shaders/geometry_instance_material.frag
@@ -1,15 +1,14 @@
-uniform float id;
+uniform int id;
 uniform vec3 eye;
 
+flat in int instanceID;
+
 in vec3 pos;
-in vec4 col;
 
 layout (location = 0) out vec4 outColor;
 
 void main()
 {
-    float instanceID = -col.x;
-
     float dist = distance(pos, eye);
-    outColor = vec4(dist, id, instanceID, 1.0);
+    outColor = vec4(dist, float(id), float(instanceID), 1.0);
 }