render: move render_world_helper, remove chunks drawn behind view

internal/render/drawtexture.frag

@@ -0,0 +1,23 @@
+#version 330
+
+#define DrawTextureChannels_R (1<<0)
+#define DrawTextureChannels_G (1<<1)
+#define DrawTextureChannels_B (1<<2)
+#define DrawTextureChannels_A (1<<3)
+
+uniform float valueMin, valueMax;
+uniform int channels;
+
+uniform sampler2D tex;
+
+in vec2 fragVert;
+in vec2 fragTexCoord;
+
+out vec4 outputColor;
+
+
+void main() {
+
+	outputColor = vec4(0, 0, 0, 1);
+
+}