Improve textwriter

Author: einarf

demosys/text/resources/shaders/demosys/text/textwriter2d.glsl

@@ -0,0 +1,74 @@
+#version 330
+
+#if defined VERTEX_SHADER
+
+in vec3 in_position;
+in uint in_char_id;
+
+uniform vec2 char_size;
+
+out uint vs_char_id;
+
+void main() {
+	gl_Position = vec4(in_position + vec3(gl_InstanceID * char_size.x, 0.0, 0.0), 1.0);
+    vs_char_id = in_char_id;
+}
+
+#elif defined GEOMETRY_SHADER
+
+layout (points) in;
+layout (triangle_strip, max_vertices = 4) out;
+
+uniform mat4 m_proj;
+uniform vec2 text_pos;
+uniform vec2 char_size;
+
+in uint vs_char_id[1];
+out vec2 uv;
+flat out uint gs_char_id;
+
+void main() {
+    vec3 pos = gl_in[0].gl_Position.xyz + vec3(text_pos, 0.0);
+
+    vec3 right = vec3(1.0, 0.0, 0.0) * char_size.x / 2.0;
+    vec3 up = vec3(0.0, 1.0, 0.0) * char_size.y / 2.0;
+
+    // upper right
+    uv = vec2(1.0, 1.0);
+    gs_char_id = vs_char_id[0];
+    gl_Position = m_proj * vec4(pos + (right + up), 1.0);
+    EmitVertex();
+
+    // upper left
+    uv = vec2(0.0, 1.0);
+    gs_char_id = vs_char_id[0];
+    gl_Position = m_proj * vec4(pos + (-right + up), 1.0);
+    EmitVertex();
+
+    // lower right
+    uv = vec2(1.0, 0.0);
+    gs_char_id = vs_char_id[0];
+    gl_Position = m_proj * vec4(pos + (right - up), 1.0);
+    EmitVertex();
+
+    // lower left
+    uv = vec2(0.0, 0.0);
+    gs_char_id = vs_char_id[0];
+    gl_Position = m_proj * vec4(pos + (-right - up), 1.0);
+    EmitVertex();
+
+    EndPrimitive();
+}
+
+#elif defined FRAGMENT_SHADER
+
+out vec4 fragColor;
+uniform sampler2DArray font_texture;
+in vec2 uv;
+flat in uint gs_char_id;
+
+void main()
+{
+    fragColor = texture(font_texture, vec3(uv, gs_char_id));
+}
+#endif

…ces/shaders/demosys/text/textwriter.glsl …s/shaders/demosys/text/textwriter3d.glsldemosys/text/resources/shaders/demosys/text/textwriter.glsl renamed to demosys/text/resources/shaders/demosys/text/textwriter3d.glsl demosys/text/resources/shaders/demosys/text/textwriter.glsl renamed to demosys/text/resources/shaders/demosys/text/textwriter3d.glsl

@@ -1,28 +1,32 @@
 import numpy
+
 import moderngl
-from demosys.opengl import VAO
+from demosys.opengl import VAO, TextureArray
 from demosys.resources import data, shaders, textures
-from demosys.opengl import TextureArray
+from pyrr import matrix44
 
 from .base import BaseText, Meta
 
 
 class TextWriter2D(BaseText):
 
-    def __init__(self, area, size=0.1, text=""):
+    def __init__(self, area, text="", aspect_ratio=1.0):
         """
         :param area: (x, y) Text area size (number of characters)
         :param size: Text size
         :param text: Initial text
         """
         super().__init__()
         self.area = area
-        self.size = size
         self._text = text.encode('latin1')
 
+        self.projection_bytes = None
+        self._aspect_ratio = 1.0
+        self.aspect_ratio = aspect_ratio
+
         self._vao = None
         self._texture = textures.get('demosys/text/VeraMono.png', cls=TextureArray, layers=190, create=True)
-        self._shader = shaders.get('demosys/text/textwriter.glsl', create=True)
+        self._shader = shaders.get('demosys/text/textwriter2d.glsl', create=True)
         self._config = data.get('demosys/text/meta.json', create=True)
 
         data.on_loaded(self._post_load)
@@ -49,11 +53,36 @@ def text(self):
     def text(self, value):
         self._text = value
 
-    def draw(self, proj_matrix, view_matrix):
-        # print(self._text, self._string_data)
+    @property
+    def aspect_ratio(self):
+        return self._aspect_ratio
+
+    @aspect_ratio.setter
+    def aspect_ratio(self, value):
+        self._aspect_ratio = value
+        self.projection_bytes = matrix44.create_orthogonal_projection_matrix(
+            -self.aspect_ratio,  # left
+            self.aspect_ratio,  # right
+            -1.0,  # bottom
+            1.0,  # top
+            -100.0,  # near
+            100.0,  # far
+            dtype=numpy.float32,
+        ).tobytes()
+
+    def draw(self, pos, size=1.0):
+        csize = (
+            self._meta.character_width / self._meta.character_height * size,
+            1.0 * size,
+        )
+        cpos = (
+            pos[0] - self._aspect_ratio + csize[0] / 2,
+            -pos[1] + 1.0 - csize[1] / 2,
+        )
+
         self._texture.use(location=0)
-        self._shader.uniform("m_proj", proj_matrix.astype('f4').tobytes())
-        self._shader.uniform("m_mv", view_matrix.astype('f4').tobytes())
+        self._shader.uniform("m_proj", self.projection_bytes)
+        self._shader.uniform("text_pos", cpos)
         self._shader.uniform("font_texture", 0)
-        self._shader.uniform("char_size", (self._meta.character_width / self._meta.character_height, 1.0))
+        self._shader.uniform("char_size", csize)
         self._vao.draw(self._shader, instances=len(self._string_data))

demosys/text/writer2d.py

@@ -14,7 +14,7 @@
     "aspect_ratio": 1.7777777777777777,
     "fullscreen": False,
     "resizable": True,
-    "title": "demosys-py",
+    "title": "Examples",
     "vsync": True,
     "cursor": True,
 }

examples/settings.py

@@ -10,15 +10,15 @@ def __init__(self):
         super().__init__()
         self.writer = TextWriter2D(
             (10, 1),
-            text="Hello world! Hello world! Hello world!")
+            aspect_ratio=self.window_aspect,
+            text="Hello world! Hello world! Hello world!",
+        )
 
     def post_load(self):
         pass
 
     @effect.bind_target
     def draw(self, time, frametime, target):
         self.ctx.disable(moderngl.CULL_FACE)
-        m_proj = self.create_projection()
-        # m_mv = matrix44.create_identity()
 
-        self.writer.draw(m_proj, self.sys_camera.view_matrix)
+        self.writer.draw((0.02, 0.01), size=0.05)