API Docs: gpu api introduction + examples

doc/python_api/examples/gpu.3.py

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+"""
+Triangle with Custom Shader
+---------------------------
+"""
+import bpy
+import gpu
+from gpu_extras.batch import batch_for_shader
+
+vertex_shader = '''
+    uniform mat4 viewProjectionMatrix;
+
+    in vec3 position;
+    out vec3 pos;
+
+    void main()
+    {
+        pos = position;
+        gl_Position = viewProjectionMatrix * vec4(position, 1.0f);
+    }
+'''
+
+fragment_shader = '''
+    uniform float brightness;
+
+    in vec3 pos;
+
+    void main()
+    {
+        gl_FragColor = vec4(pos * brightness, 1.0);
+    }
+'''
+
+coords = [(1, 1, 1), (2, 0, 0), (-2, -1, 3)]
+shader = gpu.types.GPUShader(vertex_shader, fragment_shader)
+batch = batch_for_shader(shader, 'TRIS', {"position" : coords})
+
+def draw():
+    shader.bind()
+    matrix = bpy.context.region_data.perspective_matrix
+    shader.uniform_float("viewProjectionMatrix", matrix)
+    shader.uniform_float("brightness", 0.5)
+    batch.draw(shader)
+
+bpy.types.SpaceView3D.draw_handler_add(draw, (), 'WINDOW', 'POST_VIEW')