diff options
Diffstat (limited to 'game/addons/zylann.hterrain/tools/brush/shaders/splat16.gdshader')
-rw-r--r-- | game/addons/zylann.hterrain/tools/brush/shaders/splat16.gdshader | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/game/addons/zylann.hterrain/tools/brush/shaders/splat16.gdshader b/game/addons/zylann.hterrain/tools/brush/shaders/splat16.gdshader new file mode 100644 index 0000000..68ebaa8 --- /dev/null +++ b/game/addons/zylann.hterrain/tools/brush/shaders/splat16.gdshader @@ -0,0 +1,81 @@ +shader_type canvas_item; +render_mode blend_disabled; + +#include "res://addons/zylann.hterrain/shaders/include/heightmap.gdshaderinc" + +uniform sampler2D u_src_texture; +uniform vec4 u_src_rect; +uniform float u_opacity = 1.0; +uniform vec4 u_splat = vec4(1.0, 0.0, 0.0, 0.0); +uniform sampler2D u_other_splatmap_1; +uniform sampler2D u_other_splatmap_2; +uniform sampler2D u_other_splatmap_3; +uniform sampler2D u_heightmap; +uniform float u_normal_min_y = 0.0; +uniform float u_normal_max_y = 1.0; + +vec2 get_src_uv(vec2 screen_uv) { + vec2 uv = u_src_rect.xy + screen_uv * u_src_rect.zw; + return uv; +} + +float sum(vec4 v) { + return v.x + v.y + v.z + v.w; +} + +float get_height(sampler2D heightmap, vec2 uv) { + return sample_heightmap(heightmap, uv); +} + +vec3 get_normal(sampler2D heightmap, vec2 pos) { + vec2 ps = vec2(1.0) / vec2(textureSize(heightmap, 0)); + float hnx = get_height(heightmap, pos + vec2(-ps.x, 0.0)); + float hpx = get_height(heightmap, pos + vec2(ps.x, 0.0)); + float hny = get_height(heightmap, pos + vec2(0.0, -ps.y)); + float hpy = get_height(heightmap, pos + vec2(0.0, ps.y)); + return normalize(vec3(hnx - hpx, 2.0, hpy - hny)); +} + +// Limits painting based on the slope, with a bit of falloff +float apply_slope_limit(float brush_value, vec3 normal, float normal_min_y, float normal_max_y) { + float normal_falloff = 0.2; + + // If an edge is at min/max, make sure it won't be affected by falloff + normal_min_y = normal_min_y <= 0.0 ? -2.0 : normal_min_y; + normal_max_y = normal_max_y >= 1.0 ? 2.0 : normal_max_y; + + brush_value *= 1.0 - smoothstep( + normal_max_y - normal_falloff, + normal_max_y + normal_falloff, normal.y); + + brush_value *= smoothstep( + normal_min_y - normal_falloff, + normal_min_y + normal_falloff, normal.y); + + return brush_value; +} + +void fragment() { + float brush_value = u_opacity * texture(TEXTURE, UV).r; + + vec2 src_uv = get_src_uv(SCREEN_UV); + vec3 normal = get_normal(u_heightmap, src_uv); + brush_value = apply_slope_limit(brush_value, normal, u_normal_min_y, u_normal_max_y); + + // It is assumed 3 other renders are done the same with the other 3 + vec4 src0 = texture(u_src_texture, src_uv); + vec4 src1 = texture(u_other_splatmap_1, src_uv); + vec4 src2 = texture(u_other_splatmap_2, src_uv); + vec4 src3 = texture(u_other_splatmap_3, src_uv); + float t = brush_value; + vec4 s0 = mix(src0, u_splat, t); + vec4 s1 = mix(src1, vec4(0.0), t); + vec4 s2 = mix(src2, vec4(0.0), t); + vec4 s3 = mix(src3, vec4(0.0), t); + float sum = sum(s0) + sum(s1) + sum(s2) + sum(s3); + s0 /= sum; + s1 /= sum; + s2 /= sum; + s3 /= sum; + COLOR = s0; +} |