66 lines
2.1 KiB
Python
66 lines
2.1 KiB
Python
# src/bg_shader.py
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import time
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import math
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from typing import Optional
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import numpy as np
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from imgui_bundle import imgui, nanovg as nvg, hello_imgui
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class BackgroundShader:
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def __init__(self):
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self.enabled = False
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self.start_time = time.time()
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self.ctx: Optional[nvg.Context] = None
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def render(self, width: float, height: float):
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if not self.enabled:
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return
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# In imgui-bundle, hello_imgui handles the background.
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# We can use the background_draw_list to draw primitives.
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# Since we don't have raw GLSL easily in Python without PyOpenGL,
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# we'll use a "faux-shader" approach with NanoVG or DrawList gradients.
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t = time.time() - self.start_time
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dl = imgui.get_background_draw_list()
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# Base deep sea color
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dl.add_rect_filled(imgui.ImVec2(0, 0), imgui.ImVec2(width, height), imgui.get_color_u32(imgui.ImVec4(0.01, 0.07, 0.20, 1.0)))
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# Layer 1: Slow moving large blobs (FBM approximation)
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for i in range(3):
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phase = t * (0.1 + i * 0.05)
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x = (math.sin(phase) * 0.5 + 0.5) * width
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y = (math.cos(phase * 0.8) * 0.5 + 0.5) * height
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radius = (0.4 + 0.2 * math.sin(t * 0.2)) * max(width, height)
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col = imgui.ImVec4(0.02, 0.26, 0.55, 0.3)
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dl.add_circle_filled(imgui.ImVec2(x, y), radius, imgui.get_color_u32(col), num_segments=32)
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# Layer 2: Shimmering caustics (Animated Lines)
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num_lines = 15
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for i in range(num_lines):
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offset = (t * 20.0 + i * (width / num_lines)) % width
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alpha = 0.1 * (1.0 + math.sin(t + i))
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col = imgui.get_color_u32(imgui.ImVec4(0.08, 0.60, 0.88, alpha))
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p1 = imgui.ImVec2(offset, 0)
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p2 = imgui.ImVec2(offset - 100, height)
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dl.add_line(p1, p2, col, thickness=2.0)
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# Vignette
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center = imgui.ImVec2(width/2, height/2)
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radius = max(width, height) * 0.8
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# Draw multiple concentric circles for a soft vignette
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for i in range(10):
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r = radius + (i * 50)
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alpha = (i / 10.0) * 0.5
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dl.add_circle(center, r, imgui.get_color_u32(imgui.ImVec4(0, 0, 0, alpha)), num_segments=64, thickness=60.0)
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_bg: Optional[BackgroundShader] = None
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def get_bg():
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global _bg
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if _bg is None:
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_bg = BackgroundShader()
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return _bg
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