axmol/core/renderer/shaders/label_sdf.frag

53 lines
2.1 KiB
GLSL

/****************************************************************************
Copyright (c) 2018-2019 Xiamen Yaji Software Co., Ltd.
https://axis-project.github.io/
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
****************************************************************************/
const char* label_distanceNormal_frag = R"(
#ifdef GL_ES
precision lowp float;
#endif
varying vec4 v_fragmentColor;
varying vec2 v_texCoord;
uniform vec4 u_textColor;
uniform sampler2D u_tex0;
void main()
{
vec4 color = texture2D(u_tex0, v_texCoord);
//the texture use dual channel 16-bit output for distance_map
//float dist = color.b+color.g/256.0;
// the texture use single channel 8-bit output for distance_map
float dist = color.a;
//TODO: Implementation 'fwidth' for glsl 1.0
float width = fwidth(dist);
//assign width for constant will lead to a little bit fuzzy,it's temporary measure.
//float width = 0.04;
//float width = 1.0/16.0;
float alpha = smoothstep(0.5-width, 0.5+width, dist) * u_textColor.a;
gl_FragColor = v_fragmentColor * vec4(u_textColor.rgb,alpha);
}
)";