From dca0123f13857ba855d4452865f664ec0dddbb08 Mon Sep 17 00:00:00 2001
From: Alberto Torres <kungfoobar@gmail.com>
Date: Sat, 21 Sep 2024 02:09:22 +0200
Subject: [PATCH] Fix many issues related to shadows.

---
 src/graphics/material.nim     |  7 ++++---
 src/objects/light.nim         | 29 ++++++++++++++++++++++++++++-
 src/shadows/shadow_common.nim |  6 ++++++
 src/shadows/simple_shadow.nim |  3 +++
 4 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/src/graphics/material.nim b/src/graphics/material.nim
index 6a21bba..c82b7bb 100644
--- a/src/graphics/material.nim
+++ b/src/graphics/material.nim
@@ -208,7 +208,7 @@ proc initShader*(self: Shader, engine: MyouEngine, material: Material,
         @[
             &"precision {precision} float;",
             &"precision {precision} int;",
-            &"precision {precision} sampler2DShadow;",
+            &"precision {precision} sampler2DArrayShadow;",
         ]
     else:
         @[]
@@ -438,6 +438,7 @@ proc initShader*(self: Shader, engine: MyouEngine, material: Material,
     if success == 0:
         let gl_log = get_shader_info_log(fragment_shader)
         let error_msg = &"Error compiling fragment shader of material {material.name}\n{gl_log}"
+        echo error_msg
         # console_error fragment
         let lines = fragment.split("\n")
         if "ERROR: 0:" in gl_log:
@@ -452,8 +453,8 @@ proc initShader*(self: Shader, engine: MyouEngine, material: Material,
             for i in max(1, line - 1000) ..< min(line + 4, lines.len):
                 console_error(&"{i} {lines[i - 1]}")
         else:
-            for i in 1 ..< lines.len:
-                console_error(&"{i} {lines[i - 1]}")
+            for i,line in lines:
+                console_error(&"{i+1} {line}")
         console_error(error_msg)
         return
     glGetProgramiv(prog, GL_LINK_STATUS, addr success)
diff --git a/src/objects/light.nim b/src/objects/light.nim
index e69e202..091e3c7 100644
--- a/src/objects/light.nim
+++ b/src/objects/light.nim
@@ -33,6 +33,7 @@
 import ../types
 import vmath except Quat
 import ../util
+import ../graphics/material
 
 when defined(nimdoc):
     type TYPES* = LightType | Light
@@ -100,6 +101,9 @@ proc newLight*(engine: MyouEngine, name: string="",
         scene.add_object(this, name=name)
     return this
 
+when defined(myouDebugShadows):
+    var debug_mesh: Mesh
+
 proc configure_shadow*(self: Light,
                        camera: Camera = nil,
                        max_distance: float32 = 0.0,
@@ -131,13 +135,16 @@ proc configure_shadow*(self: Light,
         # TODO: instead of a ground plane, we can just exclude the largest
         # convex object, as long as we can clamp the polygons outside the
         # frustum. Can we avoid clipping by setting W?
+        
         self.scene.update_all_matrices()
         var casters: seq[Vec3]
-        for ob in self.scene.children:
+        for ob in objects:
             if not (ob.is_mesh and ob.visible):
                 continue
             let me = ob.get_mesh
             let bb = me.bound_box
+            if bb[0] == bb[1]:
+                continue
             let world_dim = (ob.world_matrix * vec4(bb[1] - bb[0], 0.0)).xyz
             var casts = true
             if world_dim.z < 0.00001:
@@ -155,9 +162,29 @@ proc configure_shadow*(self: Light,
                         break
                 casts = not all_above
             if casts:
+                echo "adding casting ", ob.name
                 for v in box_corners(bb):
                     casters.add ob.world_matrix * v
 
+        if casters.len == 0:
+            return
+        when defined(myouDebugShadows):
+            if debug_mesh.nonNil:
+                debug_mesh.destroy()
+            debug_mesh = self.engine.newMesh(vertex_count = 100, draw_method = Lines)
+            debug_mesh.materials.add self.engine.newSolidMaterial("green", vec4(0,1,0,1))
+            debug_mesh.visible = true
+            self.scene.add_object debug_mesh
+
+            let hull = quickhull(casters)
+            for f in hull:
+                debug_mesh.add_vertex f.points[0], vec4(1)
+                for v in f.points[1..^1]:
+                    debug_mesh.add_vertex v, vec4(1)
+                    debug_mesh.add_vertex v, vec4(1)
+                debug_mesh.add_vertex f.points[0], vec4(1)
+            debug_mesh.data.update_varray()
+
         casters = quickhull_points(casters)
         let shadow = newSimpleShadowManager(self, use_camera = false)
         shadow.caster_bounding_points = casters
diff --git a/src/shadows/shadow_common.nim b/src/shadows/shadow_common.nim
index b10aa8c..9d82b74 100644
--- a/src/shadows/shadow_common.nim
+++ b/src/shadows/shadow_common.nim
@@ -38,6 +38,12 @@ proc updateShadowStorage*(scene: Scene) =
     let fb_size = scene.shadow_map_resolution
     assert color_channels <= 4
     if scene.shadow_maps != nil:
+        # TODO: we're assuming that if it exists it has all the same parameters
+        # and that only resolution and number of layers will change
+        if scene.shadow_maps.width == fb_size and
+            scene.shadow_maps.layer_count == count:
+                scene.calculate_max_lights_and_cubemaps()
+                return
         scene.shadow_maps.destroy()
     scene.shadow_maps = scene.engine.newFramebuffer(fb_size, fb_size,
             if color_channels != 0:
diff --git a/src/shadows/simple_shadow.nim b/src/shadows/simple_shadow.nim
index 2b2372d..be0eb03 100644
--- a/src/shadows/simple_shadow.nim
+++ b/src/shadows/simple_shadow.nim
@@ -97,6 +97,8 @@ proc newSimpleShadowManager*(light: Light;
             self.uses_depth = false
 
         when defined(myouDebugShadows):
+            if debug_mesh != nil:
+                debug_mesh.destroy()
             debug_mesh = self.engine.newMesh(vertex_count = 100, draw_method = Lines)
             debug_mesh.materials.add self.engine.newSolidMaterial("green", vec4(0,1,0,1))
             debug_mesh.visible = false
@@ -105,6 +107,7 @@ proc newSimpleShadowManager*(light: Light;
 method destroy*(self: SimpleShadowManager) {.locks:"unknown".} =
     if self.material != nil:
         self.material.destroy()
+        debug_mesh.destroy()
 
 when defined(myouDebugShadows):
     proc show_mat(mat: Mat4) =