Merge commit godotengine/godot@0f5f3bc9546b46b2029fc8896dc859697f1eab97

1 files changed, 28 insertions, 17 deletions

diff --git a/drivers/gles3/rasterizer_canvas_gles3.cpp b/drivers/gles3/rasterizer_canvas_gles3.cpp
index 09f9c4625c..b4160178c1 100644
--- a/drivers/gles3/rasterizer_canvas_gles3.cpp
+++ b/drivers/gles3/rasterizer_canvas_gles3.cpp
@@ -1656,28 +1656,39 @@ void RasterizerCanvasGLES3::light_update_shadow(RID p_rid, int p_shadow_index, c
 		return;
 	}
 
-	for (int i = 0; i < 4; i++) {
-		glViewport((state.shadow_texture_size / 4) * i, p_shadow_index * 2, (state.shadow_texture_size / 4), 2);
+	Projection projection;
+	{
+		real_t fov = 90;
+		real_t nearp = p_near;
+		real_t farp = p_far;
+		real_t aspect = 1.0;
 
-		Projection projection;
-		{
-			real_t fov = 90;
-			real_t nearp = p_near;
-			real_t farp = p_far;
-			real_t aspect = 1.0;
+		real_t ymax = nearp * Math::tan(Math::deg_to_rad(fov * 0.5));
+		real_t ymin = -ymax;
+		real_t xmin = ymin * aspect;
+		real_t xmax = ymax * aspect;
 
-			real_t ymax = nearp * Math::tan(Math::deg_to_rad(fov * 0.5));
-			real_t ymin = -ymax;
-			real_t xmin = ymin * aspect;
-			real_t xmax = ymax * aspect;
+		projection.set_frustum(xmin, xmax, ymin, ymax, nearp, farp);
+	}
 
-			projection.set_frustum(xmin, xmax, ymin, ymax, nearp, farp);
-		}
+	// Precomputed:
+	// Vector3 cam_target = Basis::from_euler(Vector3(0, 0, Math_TAU * ((i + 3) / 4.0))).xform(Vector3(0, 1, 0));
+	// projection = projection * Projection(Transform3D().looking_at(cam_targets[i], Vector3(0, 0, -1)).affine_inverse());
+	const Projection projections[4] = {
+		projection * Projection(Vector4(0, 0, -1, 0), Vector4(1, 0, 0, 0), Vector4(0, -1, 0, 0), Vector4(0, 0, 0, 1)),
 
-		Vector3 cam_target = Basis::from_euler(Vector3(0, 0, Math_TAU * ((i + 3) / 4.0))).xform(Vector3(0, 1, 0));
+		projection * Projection(Vector4(-1, 0, 0, 0), Vector4(0, 0, -1, 0), Vector4(0, -1, 0, 0), Vector4(0, 0, 0, 1)),
+
+		projection * Projection(Vector4(0, 0, 1, 0), Vector4(-1, 0, 0, 0), Vector4(0, -1, 0, 0), Vector4(0, 0, 0, 1)),
+
+		projection * Projection(Vector4(1, 0, 0, 0), Vector4(0, 0, 1, 0), Vector4(0, -1, 0, 0), Vector4(0, 0, 0, 1))
+
+	};
+
+	for (int i = 0; i < 4; i++) {
+		glViewport((state.shadow_texture_size / 4) * i, p_shadow_index * 2, (state.shadow_texture_size / 4), 2);
 
-		projection = projection * Projection(Transform3D().looking_at(cam_target, Vector3(0, 0, -1)).affine_inverse());
-		shadow_render.shader.version_set_uniform(CanvasOcclusionShaderGLES3::PROJECTION, projection, shadow_render.shader_version, variant);
+		shadow_render.shader.version_set_uniform(CanvasOcclusionShaderGLES3::PROJECTION, projections[i], shadow_render.shader_version, variant);
 
 		static const Vector2 directions[4] = { Vector2(1, 0), Vector2(0, 1), Vector2(-1, 0), Vector2(0, -1) };
 		shadow_render.shader.version_set_uniform(CanvasOcclusionShaderGLES3::DIRECTION, directions[i].x, directions[i].y, shadow_render.shader_version, variant);