e2dc63c5de
644fb2b679 fixed a long standing issue
that offscreen example showed the wrong colors. However the fix assumes
that input texture color space is always sRGB.
This adds a shader variation that draws textures that are stored in scene referred
linear color space (like all of our Image data-block).
Co-authored-by: Clément Foucault <foucault.clem@gmail.com>
Pull Request: https://projects.blender.org/blender/blender/pulls/147788
103 lines
3.7 KiB
Python
103 lines
3.7 KiB
Python
# SPDX-FileCopyrightText: 2018-2023 Blender Authors
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#
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# SPDX-License-Identifier: GPL-2.0-or-later
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__all__ = (
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"draw_circle_2d",
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"draw_texture_2d",
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)
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def draw_circle_2d(position, color, radius, *, segments=None):
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"""
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Draw a circle.
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:arg position: 2D position where the circle will be drawn.
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:type position: Sequence[float]
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:arg color: Color of the circle (RGBA).
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To use transparency blend must be set to ``ALPHA``, see: :func:`gpu.state.blend_set`.
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:type color: Sequence[float]
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:arg radius: Radius of the circle.
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:type radius: float
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:arg segments: How many segments will be used to draw the circle.
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Higher values give better results but the drawing will take longer.
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If None or not specified, an automatic value will be calculated.
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:type segments: int | None
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"""
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from math import sin, cos, pi, ceil, acos
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import gpu
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from gpu.types import (
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GPUBatch,
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GPUVertBuf,
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GPUVertFormat,
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)
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if segments is None:
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max_pixel_error = 0.25 # TODO: multiply 0.5 by display dpi
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segments = int(ceil(pi / acos(1.0 - max_pixel_error / radius)))
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segments = max(segments, 8)
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segments = min(segments, 1000)
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if segments <= 0:
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raise ValueError("Amount of segments must be greater than 0.")
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with gpu.matrix.push_pop():
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gpu.matrix.translate(position)
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gpu.matrix.scale_uniform(radius)
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mul = (1.0 / (segments - 1)) * (pi * 2)
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verts = [(sin(i * mul), cos(i * mul)) for i in range(segments)]
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fmt = GPUVertFormat()
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pos_id = fmt.attr_add(id="pos", comp_type='F32', len=2, fetch_mode='FLOAT')
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vbo = GPUVertBuf(len=len(verts), format=fmt)
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vbo.attr_fill(id=pos_id, data=verts)
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batch = GPUBatch(type='LINE_STRIP', buf=vbo)
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shader = gpu.shader.from_builtin('POLYLINE_UNIFORM_COLOR')
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shader.uniform_float("viewportSize", gpu.state.viewport_get()[2:])
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shader.uniform_float("lineWidth", gpu.state.line_width_get())
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shader.uniform_float("color", color)
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batch.draw(shader)
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def draw_texture_2d(texture, position, width, height, is_scene_linear_with_rec709_srgb_target=False):
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"""
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Draw a 2d texture.
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:arg texture: GPUTexture to draw (e.g. gpu.texture.from_image(image) for :class:`bpy.types.Image`).
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:type texture: :class:`gpu.types.GPUTexture`
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:arg position: Position of the lower left corner.
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:type position: 2D Vector
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:arg width: Width of the image when drawn (not necessarily
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the original width of the texture).
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:type width: float
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:arg height: Height of the image when drawn.
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:type height: float
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:arg is_scene_linear_with_rec709_srgb_target:
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True if the `texture` is stored in scene linear color space and
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the destination framebuffer uses the Rec.709 sRGB color space
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(which is true when drawing textures acquired from :class:`bpy.types.Image` inside a
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'PRE_VIEW', 'POST_VIEW' or 'POST_PIXEL' draw handler).
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Otherwise the color space is assumed to match the one of the framebuffer. (default=False)
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:type is_scene_linear_with_rec709_srgb_target: bool
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"""
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import gpu
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from . batch import batch_for_shader
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coords = ((0, 0), (1, 0), (1, 1), (0, 1))
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indices = ((0, 1, 2), (2, 3, 0))
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shader = gpu.shader.from_builtin(
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'IMAGE_SCENE_LINEAR_TO_REC709_SRGB' if is_scene_linear_with_rec709_srgb_target else 'IMAGE')
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batch = batch_for_shader(
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shader, 'TRIS',
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{"pos": coords, "texCoord": coords},
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indices=indices
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)
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with gpu.matrix.push_pop():
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gpu.matrix.translate(position)
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gpu.matrix.scale((width, height))
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shader.uniform_sampler("image", texture)
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batch.draw(shader)
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