Downgrade OpenGL to 3.3 since no 4.0+ features were used

src/main/kotlin/ru/dbotthepony/kstarbound/client/StarboundClient.kt

@@ -173,8 +173,8 @@ class StarboundClient : Closeable {
 
 		GLFW.glfwWindowHint(GLFW.GLFW_VISIBLE, GLFW.GLFW_FALSE)
 		GLFW.glfwWindowHint(GLFW.GLFW_RESIZABLE, GLFW.GLFW_TRUE)
-		GLFW.glfwWindowHint(GLFW.GLFW_CONTEXT_VERSION_MAJOR, 4)
-		GLFW.glfwWindowHint(GLFW.GLFW_CONTEXT_VERSION_MINOR, 6)
+		GLFW.glfwWindowHint(GLFW.GLFW_CONTEXT_VERSION_MAJOR, 3)
+		GLFW.glfwWindowHint(GLFW.GLFW_CONTEXT_VERSION_MINOR, 3)
 		GLFW.glfwWindowHint(GLFW.GLFW_OPENGL_PROFILE, GLFW.GLFW_OPENGL_CORE_PROFILE)
 
 		window = GLFW.glfwCreateWindow(800, 600, "KStarbound", MemoryUtil.NULL, MemoryUtil.NULL)
@@ -843,7 +843,6 @@ class StarboundClient : Closeable {
 		ensureSameThread()
 
 		var diff = nextRender - System.nanoTime()
-		var yields = 0
 
 		// try to sleep until next frame as precise as possible
 		while (diff > 0L) {
@@ -851,7 +850,6 @@ class StarboundClient : Closeable {
 				LockSupport.parkNanos(1_000_000L)
 			} else {
 				Thread.yield()
-				yields++
 			}
 
 			diff = nextRender - System.nanoTime()

src/main/kotlin/ru/dbotthepony/kstarbound/client/world/ClientWorld.kt

@@ -90,7 +90,7 @@ class ClientWorld(
 						val tile = view.getTile(x, y) ?: continue
 						val material = tile.material
 
-						if (material != null && !material.isMeta) {
+						if (!material.isMeta) {
 							client.tileRenderers.getMaterialRenderer(material.materialName).tesselate(tile, view, meshes, Vector2i(x, y), background = isBackground)
 						}
 

src/main/resources/shaders/flat.fsh

@@ -1,5 +1,5 @@
 
-#version 460
+#version 330
 
 uniform vec4 color;
 out vec4 color_out;

src/main/resources/shaders/flat.vsh

@@ -1,5 +1,5 @@
 
-#version 460
+#version 330
 
 layout (location = 0) in vec2 pos;
 uniform mat4 transform;

src/main/resources/shaders/flat_color.fsh

@@ -1,5 +1,5 @@
 
-#version 460
+#version 330
 
 in vec4 finalVertexColor;
 

src/main/resources/shaders/flat_color.vsh

@@ -1,5 +1,5 @@
 
-#version 460
+#version 330
 
 layout (location = 0) in vec2 vertexPos;
 layout (location = 1) in vec4 vertexColor;

src/main/resources/shaders/font.fsh

@@ -1,5 +1,5 @@
 
-#version 460
+#version 330
 
 in vec2 uv_out;
 out vec4 color_out;

src/main/resources/shaders/font.vsh

@@ -1,5 +1,5 @@
 
-#version 460
+#version 330
 
 layout (location = 0) in vec2 pos;
 layout (location = 1) in vec2 uv_in;

src/main/resources/shaders/fragment/texture.glsl

@@ -1,5 +1,5 @@
 
-#version 460
+#version 330
 
 uniform sampler2D texture0;
 

src/main/resources/shaders/fragment/texture_color.glsl

@@ -1,5 +1,5 @@
 
-#version 460
+#version 330
 
 uniform sampler2D texture0;
 uniform vec4 color;

src/main/resources/shaders/light.fsh

@@ -1,5 +1,5 @@
 
-#version 460
+#version 330
 
 in vec2 oUVCoords;
 out vec4 resultColor;

src/main/resources/shaders/light.vsh

@@ -1,5 +1,5 @@
 
-#version 460
+#version 330
 
 layout (location = 0) in vec2 vertexPos;
 layout (location = 1) in vec2 uvCoords;

src/main/resources/shaders/liquid.fsh

@@ -1,5 +1,5 @@
 
-#version 460
+#version 330
 
 out vec4 resultColor;
 

src/main/resources/shaders/liquid.vsh

@@ -1,5 +1,5 @@
 
-#version 460
+#version 330
 
 layout (location = 0) in vec2 vertexPos;
 

src/main/resources/shaders/tile.fsh

@@ -1,5 +1,5 @@
 
-#version 460
+#version 330
 
 uniform sampler2D texture0;
 uniform vec4 color;

src/main/resources/shaders/tile.vsh

@@ -1,5 +1,5 @@
 
-#version 460
+#version 330
 
 layout (location = 0) in vec3 pos;
 layout (location = 1) in vec2 uv_in;

src/main/resources/shaders/vertex/2dtexture.glsl

@@ -1,5 +1,5 @@
 
-#version 460
+#version 330
 
 layout (location = 0) in vec2 pos;
 layout (location = 1) in vec2 uv_in;

src/main/resources/shaders/vertex/texture.glsl

@@ -1,5 +1,5 @@
 
-#version 460
+#version 330
 
 layout (location = 0) in vec3 pos;
 layout (location = 1) in vec2 uv_in;