2022-04-07 18:46:57 +02:00

100 lines
2.4 KiB
Python

# OpenGL/Metal rendering test: render a red triangle to a texture
# and save it to a PNG file
import sys
sys.path.append('python')
import nanogui
from nanogui import Shader, Texture, RenderPass, Screen
import numpy as np
from PIL import Image
nanogui.init()
if nanogui.api == 'opengl':
s = Screen([16, 16], "Unnamed")
vertex_program = '''
#version 330
in vec3 position;
void main() {
gl_Position = vec4(position, 1.0);
}
'''
fragment_program = '''
#version 330
uniform vec4 color;
out vec4 fragColor;
void main() {
fragColor = color;
}
'''
elif nanogui.api == 'metal':
vertex_program = '''
using namespace metal;
struct VertexOut {
float4 position [[position]];
};
vertex VertexOut vertex_main(const device packed_float3 *position,
uint id [[vertex_id]]) {
VertexOut vert;
vert.position = float4(position[id], 1.f);
return vert;
}
'''
fragment_program = '''
using namespace metal;
struct VertexOut {
float4 position [[position]];
};
fragment float4 fragment_main(VertexOut vert [[stage_in]],
const constant float4 &color) {
return color;
}
'''
texture = Texture(
pixel_format=Texture.PixelFormat.RGBA,
component_format=Texture.ComponentFormat.UInt8,
size=[512, 512],
flags=Texture.TextureFlags.ShaderRead | Texture.TextureFlags.RenderTarget
)
render_pass = RenderPass([texture])
render_pass.set_viewport(
[10, 10], [512 - 10, 512 - 20]
)
shader = Shader(
render_pass,
"test_shader",
vertex_program,
fragment_program
)
p = np.array([[ 0.0, 0.5, 0],
[-0.5, -0.5, 0],
[ 0.5, -0.5, 0]], dtype=np.float32)
shader.set_buffer("position", p)
shader.set_buffer("color", np.array([1, 0, 0, 1], dtype=np.float32))
shader.set_buffer("indices", np.array([0, 1, 2], dtype=np.uint32))
with render_pass:
with shader:
if False:
shader.draw_array(Shader.PrimitiveType.Triangle, 0, 3)
else:
shader.draw_array(Shader.PrimitiveType.Triangle, 0, 3, indexed=True)
result = texture.download()
Image.fromarray(result).save('test_0_%s.png' % nanogui.api)