double-hit-balls/assets/parallax_fragment.txt

68 lines
1.9 KiB
Plaintext
Executable File

precision mediump float;
uniform sampler2D Texture;
uniform sampler2D NormalMap;
uniform sampler2D HeightMap;
precision highp float;
varying vec2 frag_uv;
varying vec3 ts_light_pos;
varying vec3 ts_view_pos;
varying vec3 ts_frag_pos;
const float num_layers = 16.0;
const float depth_scale = 0.01;
vec2 parallax_uv(vec2 uv, vec3 view_dir)
{
float layer_depth = 1.0 / num_layers;
float cur_layer_depth = 0.0;
vec2 delta_uv = view_dir.xy * depth_scale / (view_dir.z * num_layers);
vec2 cur_uv = uv;
float depth_from_tex = texture2D(HeightMap, cur_uv).r;
for (int i = 0; i < 32; i++) {
cur_layer_depth += layer_depth;
cur_uv -= delta_uv;
depth_from_tex = texture2D(HeightMap, cur_uv).r;
if (depth_from_tex < cur_layer_depth) {
break;
}
}
// Parallax occlusion mapping
vec2 prev_uv = cur_uv + delta_uv;
float next = depth_from_tex - cur_layer_depth;
float prev = texture2D(HeightMap, prev_uv).r - cur_layer_depth
+ layer_depth;
float weight = next / (next - prev);
return mix(cur_uv, prev_uv, weight);
}
void main(void)
{
vec3 light_dir = normalize(ts_light_pos - ts_frag_pos);
vec3 view_dir = normalize(ts_view_pos - ts_frag_pos);
// Only perturb the texture coordinates if a parallax technique is selected
vec2 uv = parallax_uv(frag_uv, view_dir);
//vec2 uv = frag_uv;
vec3 albedo = texture2D(Texture, uv).rgb;
vec3 ambient = 0.3 * albedo;
// Normal mapping
vec3 norm = normalize(texture2D(NormalMap, uv).rgb * 2.0 - 1.0);
float diffuse = max(dot(light_dir, norm), 0.0);
gl_FragColor = vec4(diffuse * albedo + ambient, 1.0);
}