ile-de-test/addons/waterways/shaders/system_renders/system_flow.gdshader
2023-10-05 20:02:23 +02:00

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shader_type spatial;
render_mode unshaded;
uniform sampler2D flowmap : hint_normal;
uniform sampler2D distmap : hint_default_white;
uniform float flow_base : hint_range(0.0, 8.0) = 0.0;
uniform float flow_steepness : hint_range(0.0, 8.0) = 2.0;
uniform float flow_distance : hint_range(0.0, 8.0) = 1.0;
uniform float flow_pressure : hint_range(0.0, 8.0) = 1.0;
uniform float flow_max : hint_range(0.0, 8.0) = 4.0;
uniform bool valid_flowmap = false;
varying vec3 binormal_world;
void vertex() {
binormal_world = (MODEL_MATRIX * vec4(BINORMAL, 0.0)).xyz;
}
void fragment() {
vec2 flow_foam_noise = textureLod(flowmap, UV2, 0.0).rg;
vec2 dist_pressure = textureLod(distmap, UV2, 0.0).xy;
vec2 flow;
float distance_map;
float pressure_map;
if (valid_flowmap) {
flow = flow_foam_noise.xy;
distance_map = (1.0 - dist_pressure.r) * 2.0;
pressure_map = dist_pressure.g * 2.0;
} else {
flow = vec2(0.5, 0.572);
distance_map = 0.5;
pressure_map = 0.5;
}
flow = (flow - 0.5) * 2.0; // remap
// calculate the steepness map
vec3 flow_viewspace = flow.x * TANGENT + flow.y * BINORMAL;
vec3 up_viewspace = (VIEW_MATRIX * vec4(0.0, 1.0, 0.0, 0.0)).xyz;
float steepness_map = max(0.0, dot(flow_viewspace, up_viewspace)) * 4.0;
float flow_force = min(flow_base + steepness_map * flow_steepness + distance_map * flow_distance + pressure_map * flow_pressure, flow_max);
flow *= flow_force;
float rotation = atan(-binormal_world.x, -binormal_world.z);
float cosine = cos(rotation);
float sine = sin(rotation);
mat2 rotation_mat = mat2(vec2(cosine, -sine), vec2(sine, cosine));
vec2 new_flow = rotation_mat * flow;
ALBEDO = vec3((new_flow), 0.0) * 0.5 + 0.5; // repack flowmap
}