minetest/client/shaders/shadow_shaders/pass1_vertex.glsl

31 lines
857 B
GLSL

uniform mat4 LightMVP; // world matrix
uniform vec4 CameraPos; // camera position
varying vec4 tPos;
uniform float xyPerspectiveBias0;
uniform float xyPerspectiveBias1;
uniform float zPerspectiveBias;
vec4 getPerspectiveFactor(in vec4 shadowPosition)
{
vec2 s = vec2(shadowPosition.x > CameraPos.x ? 1.0 : -1.0, shadowPosition.y > CameraPos.y ? 1.0 : -1.0);
vec2 l = s * (shadowPosition.xy - CameraPos.xy) / (1.0 - s * CameraPos.xy);
float pDistance = length(l);
float pFactor = pDistance * xyPerspectiveBias0 + xyPerspectiveBias1;
l /= pFactor;
shadowPosition.xy = CameraPos.xy * (1.0 - l) + s * l;
shadowPosition.z *= zPerspectiveBias;
return shadowPosition;
}
void main()
{
vec4 pos = LightMVP * gl_Vertex;
tPos = getPerspectiveFactor(pos);
gl_Position = vec4(tPos.xyz, 1.0);
gl_TexCoord[0] = gl_TextureMatrix[0] * gl_MultiTexCoord0;
}