minetest/client/shaders/nodes_shader/opengl_fragment.glsl

178 lines
4.6 KiB
GLSL

uniform sampler2D baseTexture;
uniform sampler2D normalTexture;
uniform sampler2D useNormalmap;
uniform vec4 skyBgColor;
uniform float fogDistance;
uniform vec3 eyePosition;
varying vec3 vPosition;
varying vec3 worldPosition;
varying float generate_heightmaps;
varying vec3 eyeVec;
varying vec3 tsEyeVec;
varying vec3 lightVec;
varying vec3 tsLightVec;
bool normalTexturePresent = false;
const float e = 2.718281828459;
const float BS = 10.0;
float intensity (vec3 color)
{
return (color.r + color.g + color.b) / 3.0;
}
float get_rgb_height (vec2 uv)
{
return intensity(texture2D(baseTexture,uv).rgb);
}
vec4 get_normal_map(vec2 uv)
{
vec4 bump = texture2D(normalTexture, uv).rgba;
bump.xyz = normalize(bump.xyz * 2.0 - 1.0);
return bump;
}
float find_intersection(vec2 dp, vec2 ds)
{
const int linear_steps = 10;
const int binary_steps = 5;
const float depth_step = 1.0 / linear_steps;
float size = depth_step;
float depth = 1.0;
float best_depth = 1.0;
for (int i = 0 ; i < linear_steps - 1 ; ++i) {
vec4 t = texture2D(normalTexture, dp + ds * depth);
if (best_depth > 0.05)
if (depth >= t.a)
best_depth = depth;
depth -= size;
}
depth = best_depth - size;
for (int i = 0 ; i < binary_steps ; ++i) {
size *= 0.5;
vec4 t = texture2D(normalTexture, dp + ds * depth);
if (depth >= t.a) {
best_depth = depth;
depth -= 2 * size;
}
depth += size;
}
return best_depth;
}
float find_intersectionRGB(vec2 dp, vec2 ds) {
const float iterations = 24;
const float depth_step = 1.0 / iterations;
float depth = 1.0;
for (int i = 0 ; i < iterations ; i++) {
float h = get_rgb_height(dp + ds * depth);
if (h >= depth)
break;
depth -= depth_step;
}
return depth;
}
void main (void)
{
vec3 color;
vec4 bump;
vec2 uv = gl_TexCoord[0].st;
bool use_normalmap = false;
#ifdef USE_NORMALMAPS
if (texture2D(useNormalmap,vec2(1.0, 1.0)).r > 0.0) {
normalTexturePresent = true;
}
#endif
#ifdef ENABLE_PARALLAX_OCCLUSION
vec3 eyeRay = normalize(tsEyeVec);
#if PARALLAX_OCCLUSION_MODE == 0
// Parallax occlusion with slope information
if (normalTexturePresent) {
const float scale = PARALLAX_OCCLUSION_SCALE / PARALLAX_OCCLUSION_ITERATIONS;
const float bias = PARALLAX_OCCLUSION_BIAS / PARALLAX_OCCLUSION_ITERATIONS;
for(int i = 0; i < PARALLAX_OCCLUSION_ITERATIONS; i++) {
vec4 normal = texture2D(normalTexture, uv.xy);
float h = normal.a * scale - bias;
uv += h * normal.z * eyeRay.xy;
}
#endif
#if PARALLAX_OCCLUSION_MODE == 1
// Relief mapping
if (normalTexturePresent) {
vec2 ds = eyeRay.xy * PARALLAX_OCCLUSION_SCALE;
float dist = find_intersection(uv, ds);
uv += dist * ds;
#endif
} else if (generate_heightmaps > 0.0) {
vec2 ds = eyeRay.xy * PARALLAX_OCCLUSION_SCALE;
float dist = find_intersectionRGB(uv, ds);
uv += dist * ds;
}
#endif
#ifdef USE_NORMALMAPS
if (normalTexturePresent) {
bump = get_normal_map(uv);
use_normalmap = true;
}
#endif
if (GENERATE_NORMALMAPS == 1 && use_normalmap == false) {
float tl = get_rgb_height(vec2(uv.x - SAMPLE_STEP, uv.y + SAMPLE_STEP));
float t = get_rgb_height(vec2(uv.x - SAMPLE_STEP, uv.y - SAMPLE_STEP));
float tr = get_rgb_height(vec2(uv.x + SAMPLE_STEP, uv.y + SAMPLE_STEP));
float r = get_rgb_height(vec2(uv.x + SAMPLE_STEP, uv.y));
float br = get_rgb_height(vec2(uv.x + SAMPLE_STEP, uv.y - SAMPLE_STEP));
float b = get_rgb_height(vec2(uv.x, uv.y - SAMPLE_STEP));
float bl = get_rgb_height(vec2(uv.x -SAMPLE_STEP, uv.y - SAMPLE_STEP));
float l = get_rgb_height(vec2(uv.x - SAMPLE_STEP, uv.y));
float dX = (tr + 2.0 * r + br) - (tl + 2.0 * l + bl);
float dY = (bl + 2.0 * b + br) - (tl + 2.0 * t + tr);
bump = vec4(normalize(vec3 (-dX, -dY, NORMALMAPS_STRENGTH)), 1.0);
use_normalmap = true;
}
vec4 base = texture2D(baseTexture, uv).rgba;
#ifdef ENABLE_BUMPMAPPING
if (use_normalmap) {
vec3 L = normalize(lightVec);
vec3 E = normalize(-eyeVec);
float specular = pow(clamp(dot(reflect(L, bump.xyz), -E), 0.0, 1.0), 1.0);
float diffuse = dot(E,bump.xyz);
color = (diffuse + 0.1 * specular) * base.rgb;
} else {
color = base.rgb;
}
#else
color = base.rgb;
#endif
#if MATERIAL_TYPE == TILE_MATERIAL_LIQUID_TRANSPARENT || MATERIAL_TYPE == TILE_MATERIAL_LIQUID_OPAQUE
float alpha = gl_Color.a;
vec4 col = vec4(color.rgb, alpha);
col *= gl_Color;
if (fogDistance != 0.0) {
float d = max(0.0, min(vPosition.z / fogDistance * 1.5 - 0.6, 1.0));
alpha = mix(alpha, 0.0, d);
}
gl_FragColor = vec4(col.rgb, alpha);
#else
vec4 col = vec4(color.rgb, base.a);
col *= gl_Color;
if (fogDistance != 0.0) {
float d = max(0.0, min(vPosition.z / fogDistance * 1.5 - 0.6, 1.0));
col = mix(col, skyBgColor, d);
}
gl_FragColor = vec4(col.rgb, base.a);
#endif
}