ddnet/data/shader/vulkan/text.frag
2022-03-21 12:39:51 +01:00

44 lines
1.6 KiB
GLSL

#version 450
#extension GL_ARB_separate_shader_objects : enable
layout(binding = 0) uniform sampler2D gTextSampler;
layout(binding = 1) uniform sampler2D gTextOutlineSampler;
layout(push_constant) uniform SFragConstBO {
layout(offset = 48) uniform vec4 gVertColor;
layout(offset = 64) uniform vec4 gVertOutlineColor;
} gFragConst;
layout (location = 0) noperspective in vec2 texCoord;
layout (location = 1) noperspective in vec4 outVertColor;
layout(location = 0) out vec4 FragClr;
void main()
{
vec4 textColor = gFragConst.gVertColor * outVertColor * vec4(1.0, 1.0, 1.0, texture(gTextSampler, texCoord).r);
vec4 textOutlineTex = gFragConst.gVertOutlineColor * vec4(1.0, 1.0, 1.0, texture(gTextOutlineSampler, texCoord).r);
// ratio between the two textures
float OutlineBlend = (1.0 - textColor.a);
// since the outline is always black, or even if it has decent colors, it can be just added to the actual color
// without loosing any or too much color
// lerp isn't commutative, so add the color the fragment looses by lerping
// this reduces the chance of false color calculation if the text is transparent
// first get the right color
vec4 textOutlineFrag = vec4(textOutlineTex.rgb * textOutlineTex.a, textOutlineTex.a) * OutlineBlend;
vec3 textFrag = (textColor.rgb * textColor.a);
vec3 finalFragColor = textOutlineFrag.rgb + textFrag;
float RealAlpha = (textOutlineFrag.a + textColor.a);
// simply add the color we will loose through blending
if(RealAlpha > 0.0)
FragClr = vec4(finalFragColor / RealAlpha, RealAlpha);
else
FragClr = vec4(0.0, 0.0, 0.0, 0.0);
}