Don't use geo shader for nine patch

Author: einarf

arcade/gui/nine_patch.py

@@ -1,6 +1,10 @@
+from array import array
+
 import arcade
-import arcade.gl as gl
+from arcade.gl import Buffer, BufferDescription, Geometry, Program
+from arcade.math import Vec2
 from arcade.texture_atlas.base import TextureAtlasBase
+from arcade.types import Rect
 
 
 class NinePatchTexture:
@@ -74,6 +78,7 @@ def __init__(
         self._initialized = False
         self._texture = texture
         self._custom_atlas = atlas
+        self._geometry_cache: tuple[int, int, int, int, Rect] | None = None
 
         # pixel texture co-ordinate start and end of central box.
         self._left = left
@@ -84,37 +89,16 @@ def __init__(
         self._check_sizes()
 
         # Created in _init_deferred
-        self._program: gl.program.Program
-        self._geometry: gl.Geometry
+        self._buffer: Buffer
+        self._program: Program
+        self._geometry: Geometry
         self._ctx: arcade.ArcadeContext
         self._atlas: TextureAtlasBase
         try:
             self._init_deferred()
         except Exception:
             pass
 
-    def _init_deferred(self):
-        """Deferred initialization when lazy loaded"""
-        self._ctx = arcade.get_window().ctx
-        # TODO: Cache in context?
-        self._program = self._ctx.load_program(
-            vertex_shader=":system:shaders/gui/nine_patch_vs.glsl",
-            geometry_shader=":system:shaders/gui/nine_patch_gs.glsl",
-            fragment_shader=":system:shaders/gui/nine_patch_fs.glsl",
-        )
-        # Configure texture channels
-        self._program.set_uniform_safe("uv_texture", 0)
-        self._program["sprite_texture"] = 1
-
-        # TODO: Cache in context?
-        self._geometry = self._ctx.geometry()
-
-        # References for the texture
-        self._atlas = self._custom_atlas or self._ctx.default_atlas
-        self._add_to_atlas(self.texture)
-
-        self._initialized = True
-
     def initialize(self) -> None:
         """
         Manually initialize the NinePatchTexture if it was lazy loaded.
@@ -141,7 +125,7 @@ def texture(self, texture: arcade.Texture):
         self._add_to_atlas(texture)
 
     @property
-    def program(self) -> gl.program.Program:
+    def program(self) -> Program:
         """Get or set the shader program.
 
         Returns the default shader if no other shader is assigned.
@@ -152,7 +136,7 @@ def program(self) -> gl.program.Program:
         return self._program
 
     @program.setter
-    def program(self, program: gl.program.Program):
+    def program(self, program: Program):
         if not self._initialized:
             raise RuntimeError("The NinePatchTexture has not been initialized")
 
@@ -241,26 +225,22 @@ def draw_rect(
         if not self._initialized:
             self._init_deferred()
 
+        self._create_geometry(rect)
+
         if blend:
             self._ctx.enable_only(self._ctx.BLEND)
         else:
             self._ctx.disable(self._ctx.BLEND)
 
-        self.program.set_uniform_safe("texture_id", self._atlas.get_texture_id(self._texture))
         if pixelated:
             self._atlas.texture.filter = self._ctx.NEAREST, self._ctx.NEAREST
         else:
             self._atlas.texture.filter = self._ctx.LINEAR, self._ctx.LINEAR
 
-        self.program["position"] = rect.bottom_left
-        self.program["start"] = self._left, self._bottom
-        self.program["end"] = self.width - self._right, self.height - self._top
-        self.program["size"] = rect.size
-        self.program["t_size"] = self._texture.size
-
         self._atlas.use_uv_texture(0)
         self._atlas.texture.use(1)
-        self._geometry.render(self._program, vertices=1)
+
+        self._geometry.render(self._program)
 
         if blend:
             self._ctx.disable(self._ctx.BLEND)
@@ -282,3 +262,218 @@ def _check_sizes(self):
             raise ValueError("Left and right border must be smaller than texture width")
         if self._bottom + self._top > self._texture.height:
             raise ValueError("Bottom and top border must be smaller than texture height")
+
+    def _init_deferred(self):
+        """Deferred initialization when lazy loaded"""
+        self._ctx = arcade.get_window().ctx
+        # TODO: Cache in context?
+        self._program = self._ctx.load_program(
+            vertex_shader=":system:shaders/gui/nine_patch_vs.glsl",
+            fragment_shader=":system:shaders/gui/nine_patch_fs.glsl",
+        )
+        # Configure texture channels
+        self._program.set_uniform_safe("uv_texture", 0)
+        self._program["sprite_texture"] = 1
+
+        # 4 byte floats * 4 floats * 4 vertices * 9 patches
+        self._buffer = self._ctx.buffer(reserve=576)
+        # fmt: off
+        self._ibo = self._ctx.buffer(
+            data=array("i",
+                [
+                    # Triangulate the patches
+                    # First rot
+                    0, 1, 2,
+                    3, 1, 2,
+
+                    4, 5, 6,
+                    7, 5, 6,
+
+                    8, 9, 10,
+                    11, 9, 10,
+
+                    # Middle row
+                    12, 13, 14,
+                    15, 13, 14,
+
+                    16, 17, 18,
+                    19, 17, 18,
+
+                    20, 21, 22,
+                    23, 21, 22,
+
+                    # Bottom row
+                    24, 25, 26,
+                    27, 25, 26,
+
+                    28, 29, 30,
+                    31, 29, 30,
+
+                    32, 33, 34,
+                    35, 33, 34,
+                ]
+            ),
+        )
+        # fmt: on
+        self._geometry = self._ctx.geometry(
+            content=[BufferDescription(self._buffer, "2f 2f", ["in_position", "in_uv"])],
+            index_buffer=self._ibo,
+            mode=self._ctx.TRIANGLES,
+            index_element_size=4,
+        )
+
+        # References for the texture
+        self._atlas = self._custom_atlas or self._ctx.default_atlas
+        self._add_to_atlas(self.texture)
+
+        # NOTE: Important to create geometry after the texture is added to the atlas
+        # self._create_geometry(LBWH(0, 0, self.width, self.height))
+        self._initialized = True
+
+    def _create_geometry(self, rect: Rect):
+        """Create vertices for the 9-patch texture."""
+        # NOTE: This was ported from glsl geometry shader to python
+        # Simulate old uniforms
+        cache_key = (self._left, self._right, self._bottom, self._top, rect)
+        if cache_key == self._geometry_cache:
+            return
+        self._geometry_cache = cache_key
+
+        position = rect.bottom_left
+        start = Vec2(self._left, self._bottom)
+        end = Vec2(self.width - self._right, self.height - self._top)
+        size = rect.size
+        t_size = Vec2(*self._texture.size)
+        atlas_size = Vec2(*self._atlas.size)
+
+        # Patch points starting from upper left row by row
+        p1 = position + Vec2(0.0, size.y)
+        p2 = position + Vec2(start.x, size.y)
+        p3 = position + Vec2(size.x - (t_size.x - end.x), size.y)
+        p4 = position + Vec2(size.x, size.y)
+
+        y = size.y - (t_size.y - end.y)
+        p5 = position + Vec2(0.0, y)
+        p6 = position + Vec2(start.x, y)
+        p7 = position + Vec2(size.x - (t_size.x - end.x), y)
+        p8 = position + Vec2(size.x, y)
+
+        p9 = position + Vec2(0.0, start.y)
+        p10 = position + Vec2(start.x, start.y)
+        p11 = position + Vec2(size.x - (t_size.x - end.x), start.y)
+        p12 = position + Vec2(size.x, start.y)
+
+        p13 = position + Vec2(0.0, 0.0)
+        p14 = position + Vec2(start.x, 0.0)
+        p15 = position + Vec2(size.x - (t_size.x - end.x), 0.0)
+        p16 = position + Vec2(size.x, 0.0)
+
+        # <AtlasRegion
+        #     x=1 y=1
+        #     width=100 height=100
+        #     uvs=(
+        #         0.001953125, 0.001953125,
+        #         0.197265625, 0.001953125,
+        #         0.001953125, 0.197265625,
+        #         0.197265625, 0.197265625,
+        #     )
+        # Get texture coordinates
+        # vec2 uv0, uv1, uv2, uv3
+        region = self._atlas.get_texture_region_info(self._texture.atlas_name)
+        tex_coords = region.texture_coordinates
+        uv0 = Vec2(tex_coords[0], tex_coords[1])
+        uv1 = Vec2(tex_coords[2], tex_coords[3])
+        uv2 = Vec2(tex_coords[4], tex_coords[5])
+        uv3 = Vec2(tex_coords[6], tex_coords[7])
+
+        # Local corner offsets in pixels
+        left = start.x
+        right = t_size.x - end.x
+        top = t_size.y - end.y
+        bottom = start.y
+
+        # UV offsets to the inner rectangle in the patch
+        # This is the global texture coordinate offset in the entire atlas
+        c1 = Vec2(left, top) / atlas_size  # Upper left corner
+        c2 = Vec2(right, top) / atlas_size  # Upper right corner
+        c3 = Vec2(left, bottom) / atlas_size  # Lower left corner
+        c4 = Vec2(right, bottom) / atlas_size  # Lower right corner
+
+        # Texture coordinates for all the points in the patch
+        t1 = uv0
+        t2 = uv0 + Vec2(c1.x, 0.0)
+        t3 = uv1 - Vec2(c2.x, 0.0)
+        t4 = uv1
+
+        t5 = uv0 + Vec2(0.0, c1.y)
+        t6 = uv0 + c1
+        t7 = uv1 + Vec2(-c2.x, c2.y)
+        t8 = uv1 + Vec2(0.0, c2.y)
+
+        t9 = uv2 - Vec2(0.0, c3.y)
+        t10 = uv2 + Vec2(c3.x, -c3.y)
+        t11 = uv3 - c4
+        t12 = uv3 - Vec2(0.0, c4.y)
+
+        t13 = uv2
+        t14 = uv2 + Vec2(c3.x, 0.0)
+        t15 = uv3 - Vec2(c4.x, 0.0)
+        t16 = uv3
+
+        # fmt: off
+        primitives = [
+            # First row - two fixed corners + stretchy middle
+            # Upper left corner. Fixed size.
+            p1, t1,
+            p5, t5,
+            p2, t2,
+            p6, t6,
+            # Upper middle part stretches on x axis
+            p2, t2,
+            p6, t6,
+            p3, t3,
+            p7, t7,
+            # Upper right corner. Fixed size
+            p3, t3,
+            p7, t7,
+            p4, t4,
+            p8, t8,
+
+            #  Middle row: Two stretchy sides + stretchy middle
+            # left border sketching on y axis
+            p5, t5,
+            p9, t9,
+            p6, t6,
+            p10, t10,
+            # Center stretchy area
+            p6, t6,
+            p10, t10,
+            p7, t7,
+            p11, t11,
+            # Right border. Stenches on y axis
+            p7, t7,
+            p11, t11,
+            p8, t8,
+            p12, t12,
+
+            # Bottom row: two fixed corners + stretchy middle
+            # Lower left corner. Fixed size.
+            p9, t9,
+            p13, t13,
+            p10, t10,
+            p14, t14,
+            # Lower middle part stretches on x axis
+            p10, t10,
+            p14, t14,
+            p11, t11,
+            p15, t15,
+            # Lower right corner. Fixed size
+            p11, t11,
+            p15, t15,
+            p12, t12,
+            p16, t16,
+        ]
+        # fmt: on
+
+        data = array("f", [coord for point in primitives for coord in point])
+        self._buffer.write(data.tobytes())

arcade/resources/system/shaders/gui/nine_patch_fs.glsl

@@ -1,10 +1,10 @@
 #version 330
 
 uniform sampler2D sprite_texture;
-out vec4 f_color;
+out vec4 fragColor;
 
 in vec2 uv;
 
 void main() {
-   f_color = texture(sprite_texture, uv);
+   fragColor = texture(sprite_texture, uv);
 }