broken lighting

shaders/triangle.frag

@@ -4,9 +4,28 @@
 layout(binding = 1) uniform sampler2D tex;
 
 layout(location = 0) in vec2 tex_coords;
+layout(location = 1) in vec3 normal_cam;
+layout(location = 2) in vec3 position_cam;
+layout(location = 3) in vec3 light_direction_cam;
 
 layout(location = 0) out vec4 out_color;
 
 void main() {
-    out_color = texture(tex, tex_coords);
+    vec3 normal_cam_u = normalize(normal_cam);
+    vec3 light_direction_cam_u = normalize(light_direction_cam);
+
+    float ambient_strength = 0.1;
+    vec3 light_color = vec3(1.0, 1.0, 1.0);
+    vec3 ambient_color = ambient_strength * light_color;
+
+    float diffuse_strength = max(0.0, dot(normal_cam_u, light_direction_cam_u));
+    vec3 diffuse_color = diffuse_strength * light_color;
+
+//    float specular_value = 1.0;
+//    vec3 view_direction = normalize(position_cam);
+//    vec3 reflect_direction = reflect(-light_direction_cam_nm, normal_cam_nm);
+//    float specular_strength = pow(max(dot(view_direction, reflect_direction), 0.0), 32);
+//    vec3 specular_color = specular_value * specular_strength * light_color;
+
+    out_color = vec4(ambient_color + diffuse_color, 1.0) * texture(tex, tex_coords);
 }

shaders/triangle.vert

@@ -1,20 +1,25 @@
 #version 450
 #extension GL_ARB_separate_shader_objects : enable
 
+layout(push_constant) uniform PushConstants {
+    mat4 model;
+} push;
+
 layout(binding = 0) uniform ObjectUniformData {
     mat4 view;
     mat4 projection;
     float time;
+    vec3 light_position;
 } ubo;
 
 layout(location = 0) in vec3 position;
 layout(location = 1) in vec2 uv;
+layout(location = 2) in vec3 normal;
 
 layout(location = 0) out vec2 tex_coords;
-
-layout(push_constant) uniform PushConstants {
-    mat4 model;
-} push;
+layout(location = 1) out vec3 normal_cam;
+layout(location = 2) out vec3 position_cam;
+layout(location = 3) out vec3 light_direction_cam;
 
 out gl_PerVertex {
     vec4 gl_Position;
@@ -23,4 +28,11 @@ out gl_PerVertex {
 void main() {
     gl_Position = ubo.projection * ubo.view * push.model * vec4(position, 1.0);
     tex_coords = uv;
+
+    position_cam = vec3(ubo.view * push.model * vec4(position, 1.0));
+    // TODO: use inverse transpose so this doesn't break when scaling
+    normal_cam = vec3(ubo.view * push.model * vec4(normal, 1.0));
+
+    vec3 light_position_cam = vec3(ubo.view * vec4(ubo.light_position, 1.0));
+    light_direction_cam = light_position_cam - position_cam;
 }