minetest/client/shaders/nodes_shader/opengl_fragment.glsl
x2048 bf3acbf388
Distribute shadow map update over multiple frames to reduce stutter (#11422)
Reduces stutter and freezes when playing.

 * Maintains double SM and SM Color textures
 * Light frustum update triggers incremental generation of shadow map into secondary 'future' textures.
 * Every incremental update renders a portion of the shadow draw list (split equally).
 * After defined number of frames (currently, 4), 'future' and 'current' textures are swapped, and DirectionalLight 'commits' the new frustum to use when rendering shadows on screen.

Co-authored-by: sfan5 <sfan5@live.de>
2021-07-25 12:36:23 +02:00

531 lines
16 KiB
GLSL

uniform sampler2D baseTexture;
uniform vec4 skyBgColor;
uniform float fogDistance;
uniform vec3 eyePosition;
// The cameraOffset is the current center of the visible world.
uniform vec3 cameraOffset;
uniform float animationTimer;
#ifdef ENABLE_DYNAMIC_SHADOWS
// shadow texture
uniform sampler2D ShadowMapSampler;
// shadow uniforms
uniform vec3 v_LightDirection;
uniform float f_textureresolution;
uniform mat4 m_ShadowViewProj;
uniform float f_shadowfar;
varying float normalOffsetScale;
varying float adj_shadow_strength;
varying float cosLight;
varying float f_normal_length;
#endif
varying vec3 vNormal;
varying vec3 vPosition;
// World position in the visible world (i.e. relative to the cameraOffset.)
// This can be used for many shader effects without loss of precision.
// If the absolute position is required it can be calculated with
// cameraOffset + worldPosition (for large coordinates the limits of float
// precision must be considered).
varying vec3 worldPosition;
varying lowp vec4 varColor;
#ifdef GL_ES
varying mediump vec2 varTexCoord;
#else
centroid varying vec2 varTexCoord;
#endif
varying vec3 eyeVec;
varying float nightRatio;
const float fogStart = FOG_START;
const float fogShadingParameter = 1.0 / ( 1.0 - fogStart);
#ifdef ENABLE_DYNAMIC_SHADOWS
const float bias0 = 0.9;
const float zPersFactor = 0.5;
const float bias1 = 1.0 - bias0 + 1e-6;
vec4 getPerspectiveFactor(in vec4 shadowPosition)
{
float pDistance = length(shadowPosition.xy);
float pFactor = pDistance * bias0 + bias1;
shadowPosition.xyz *= vec3(vec2(1.0 / pFactor), zPersFactor);
return shadowPosition;
}
// assuming near is always 1.0
float getLinearDepth()
{
return 2.0 * f_shadowfar / (f_shadowfar + 1.0 - (2.0 * gl_FragCoord.z - 1.0) * (f_shadowfar - 1.0));
}
vec3 getLightSpacePosition()
{
vec4 pLightSpace;
// some drawtypes have zero normals, so we need to handle it :(
#if DRAW_TYPE == NDT_PLANTLIKE
pLightSpace = m_ShadowViewProj * vec4(worldPosition, 1.0);
#else
float offsetScale = (0.0057 * getLinearDepth() + normalOffsetScale);
pLightSpace = m_ShadowViewProj * vec4(worldPosition + offsetScale * normalize(vNormal), 1.0);
#endif
pLightSpace = getPerspectiveFactor(pLightSpace);
return pLightSpace.xyz * 0.5 + 0.5;
}
// custom smoothstep implementation because it's not defined in glsl1.2
// https://docs.gl/sl4/smoothstep
float mtsmoothstep(in float edge0, in float edge1, in float x)
{
float t = clamp((x - edge0) / (edge1 - edge0), 0.0, 1.0);
return t * t * (3.0 - 2.0 * t);
}
#ifdef COLORED_SHADOWS
// c_precision of 128 fits within 7 base-10 digits
const float c_precision = 128.0;
const float c_precisionp1 = c_precision + 1.0;
float packColor(vec3 color)
{
return floor(color.b * c_precision + 0.5)
+ floor(color.g * c_precision + 0.5) * c_precisionp1
+ floor(color.r * c_precision + 0.5) * c_precisionp1 * c_precisionp1;
}
vec3 unpackColor(float value)
{
vec3 color;
color.b = mod(value, c_precisionp1) / c_precision;
color.g = mod(floor(value / c_precisionp1), c_precisionp1) / c_precision;
color.r = floor(value / (c_precisionp1 * c_precisionp1)) / c_precision;
return color;
}
vec4 getHardShadowColor(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
{
vec4 texDepth = texture2D(shadowsampler, smTexCoord.xy).rgba;
float visibility = step(0.0, realDistance - texDepth.r);
vec4 result = vec4(visibility, vec3(0.0,0.0,0.0));//unpackColor(texDepth.g));
if (visibility < 0.1) {
visibility = step(0.0, realDistance - texDepth.b);
result = vec4(visibility, unpackColor(texDepth.a));
}
return result;
}
#else
float getHardShadow(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
{
float texDepth = texture2D(shadowsampler, smTexCoord.xy).r;
float visibility = step(0.0, realDistance - texDepth);
return visibility;
}
#endif
#if SHADOW_FILTER == 2
#define PCFBOUND 3.5
#define PCFSAMPLES 64.0
#elif SHADOW_FILTER == 1
#define PCFBOUND 1.5
#if defined(POISSON_FILTER)
#define PCFSAMPLES 32.0
#else
#define PCFSAMPLES 16.0
#endif
#else
#define PCFBOUND 0.0
#if defined(POISSON_FILTER)
#define PCFSAMPLES 4.0
#else
#define PCFSAMPLES 1.0
#endif
#endif
#ifdef COLORED_SHADOWS
float getHardShadowDepth(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
{
vec4 texDepth = texture2D(shadowsampler, smTexCoord.xy);
float depth = max(realDistance - texDepth.r, realDistance - texDepth.b);
return depth;
}
#else
float getHardShadowDepth(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
{
float texDepth = texture2D(shadowsampler, smTexCoord.xy).r;
float depth = realDistance - texDepth;
return depth;
}
#endif
float getBaseLength(vec2 smTexCoord)
{
float l = length(2.0 * smTexCoord.xy - 1.0); // length in texture coords
return bias1 / (1.0 / l - bias0); // return to undistorted coords
}
float getDeltaPerspectiveFactor(float l)
{
return 0.1 / (bias0 * l + bias1); // original distortion factor, divided by 10
}
float getPenumbraRadius(sampler2D shadowsampler, vec2 smTexCoord, float realDistance, float multiplier)
{
float baseLength = getBaseLength(smTexCoord);
float perspectiveFactor;
// Return fast if sharp shadows are requested
if (SOFTSHADOWRADIUS <= 1.0) {
perspectiveFactor = getDeltaPerspectiveFactor(baseLength);
return max(2 * length(smTexCoord.xy) * 2048 / f_textureresolution / pow(perspectiveFactor, 3), SOFTSHADOWRADIUS);
}
vec2 clampedpos;
float texture_size = 1.0 / (2048 /*f_textureresolution*/ * 0.5);
float y, x;
float depth = 0.0;
float pointDepth;
float maxRadius = SOFTSHADOWRADIUS * 5.0 * multiplier;
float bound = clamp(PCFBOUND * (1 - baseLength), 0.0, PCFBOUND);
int n = 0;
for (y = -bound; y <= bound; y += 1.0)
for (x = -bound; x <= bound; x += 1.0) {
clampedpos = vec2(x,y);
perspectiveFactor = getDeltaPerspectiveFactor(baseLength + length(clampedpos) * texture_size * maxRadius);
clampedpos = clampedpos * texture_size * perspectiveFactor * maxRadius * perspectiveFactor + smTexCoord.xy;
pointDepth = getHardShadowDepth(shadowsampler, clampedpos.xy, realDistance);
if (pointDepth > -0.01) {
depth += pointDepth;
n += 1;
}
}
depth = depth / n;
depth = pow(clamp(depth, 0.0, 1000.0), 1.6) / 0.001;
perspectiveFactor = getDeltaPerspectiveFactor(baseLength);
return max(length(smTexCoord.xy) * 2 * 2048 / f_textureresolution / pow(perspectiveFactor, 3), depth * maxRadius);
}
#ifdef POISSON_FILTER
const vec2[64] poissonDisk = vec2[64](
vec2(0.170019, -0.040254),
vec2(-0.299417, 0.791925),
vec2(0.645680, 0.493210),
vec2(-0.651784, 0.717887),
vec2(0.421003, 0.027070),
vec2(-0.817194, -0.271096),
vec2(-0.705374, -0.668203),
vec2(0.977050, -0.108615),
vec2(0.063326, 0.142369),
vec2(0.203528, 0.214331),
vec2(-0.667531, 0.326090),
vec2(-0.098422, -0.295755),
vec2(-0.885922, 0.215369),
vec2(0.566637, 0.605213),
vec2(0.039766, -0.396100),
vec2(0.751946, 0.453352),
vec2(0.078707, -0.715323),
vec2(-0.075838, -0.529344),
vec2(0.724479, -0.580798),
vec2(0.222999, -0.215125),
vec2(-0.467574, -0.405438),
vec2(-0.248268, -0.814753),
vec2(0.354411, -0.887570),
vec2(0.175817, 0.382366),
vec2(0.487472, -0.063082),
vec2(0.355476, 0.025357),
vec2(-0.084078, 0.898312),
vec2(0.488876, -0.783441),
vec2(0.470016, 0.217933),
vec2(-0.696890, -0.549791),
vec2(-0.149693, 0.605762),
vec2(0.034211, 0.979980),
vec2(0.503098, -0.308878),
vec2(-0.016205, -0.872921),
vec2(0.385784, -0.393902),
vec2(-0.146886, -0.859249),
vec2(0.643361, 0.164098),
vec2(0.634388, -0.049471),
vec2(-0.688894, 0.007843),
vec2(0.464034, -0.188818),
vec2(-0.440840, 0.137486),
vec2(0.364483, 0.511704),
vec2(0.034028, 0.325968),
vec2(0.099094, -0.308023),
vec2(0.693960, -0.366253),
vec2(0.678884, -0.204688),
vec2(0.001801, 0.780328),
vec2(0.145177, -0.898984),
vec2(0.062655, -0.611866),
vec2(0.315226, -0.604297),
vec2(-0.780145, 0.486251),
vec2(-0.371868, 0.882138),
vec2(0.200476, 0.494430),
vec2(-0.494552, -0.711051),
vec2(0.612476, 0.705252),
vec2(-0.578845, -0.768792),
vec2(-0.772454, -0.090976),
vec2(0.504440, 0.372295),
vec2(0.155736, 0.065157),
vec2(0.391522, 0.849605),
vec2(-0.620106, -0.328104),
vec2(0.789239, -0.419965),
vec2(-0.545396, 0.538133),
vec2(-0.178564, -0.596057)
);
#ifdef COLORED_SHADOWS
vec4 getShadowColor(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
{
vec2 clampedpos;
vec4 visibility = vec4(0.0);
float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance, 1.5); // scale to align with PCF
if (radius < 0.1) {
// we are in the middle of even brightness, no need for filtering
return getHardShadowColor(shadowsampler, smTexCoord.xy, realDistance);
}
float baseLength = getBaseLength(smTexCoord);
float perspectiveFactor;
float texture_size = 1.0 / (f_textureresolution * 0.5);
int samples = int(clamp(PCFSAMPLES * (1 - baseLength) * (1 - baseLength), PCFSAMPLES / 4, PCFSAMPLES));
int init_offset = int(floor(mod(((smTexCoord.x * 34.0) + 1.0) * smTexCoord.y, 64.0-samples)));
int end_offset = int(samples) + init_offset;
for (int x = init_offset; x < end_offset; x++) {
clampedpos = poissonDisk[x];
perspectiveFactor = getDeltaPerspectiveFactor(baseLength + length(clampedpos) * texture_size * radius);
clampedpos = clampedpos * texture_size * perspectiveFactor * radius * perspectiveFactor + smTexCoord.xy;
visibility += getHardShadowColor(shadowsampler, clampedpos.xy, realDistance);
}
return visibility / samples;
}
#else
float getShadow(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
{
vec2 clampedpos;
float visibility = 0.0;
float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance, 1.5); // scale to align with PCF
if (radius < 0.1) {
// we are in the middle of even brightness, no need for filtering
return getHardShadow(shadowsampler, smTexCoord.xy, realDistance);
}
float baseLength = getBaseLength(smTexCoord);
float perspectiveFactor;
float texture_size = 1.0 / (f_textureresolution * 0.5);
int samples = int(clamp(PCFSAMPLES * (1 - baseLength) * (1 - baseLength), PCFSAMPLES / 4, PCFSAMPLES));
int init_offset = int(floor(mod(((smTexCoord.x * 34.0) + 1.0) * smTexCoord.y, 64.0-samples)));
int end_offset = int(samples) + init_offset;
for (int x = init_offset; x < end_offset; x++) {
clampedpos = poissonDisk[x];
perspectiveFactor = getDeltaPerspectiveFactor(baseLength + length(clampedpos) * texture_size * radius);
clampedpos = clampedpos * texture_size * perspectiveFactor * radius * perspectiveFactor + smTexCoord.xy;
visibility += getHardShadow(shadowsampler, clampedpos.xy, realDistance);
}
return visibility / samples;
}
#endif
#else
/* poisson filter disabled */
#ifdef COLORED_SHADOWS
vec4 getShadowColor(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
{
vec2 clampedpos;
vec4 visibility = vec4(0.0);
float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance, 1.0);
if (radius < 0.1) {
// we are in the middle of even brightness, no need for filtering
return getHardShadowColor(shadowsampler, smTexCoord.xy, realDistance);
}
float baseLength = getBaseLength(smTexCoord);
float perspectiveFactor;
float texture_size = 1.0 / (f_textureresolution * 0.5);
float y, x;
float bound = clamp(PCFBOUND * (1 - baseLength), PCFBOUND / 2, PCFBOUND);
int n = 0;
// basic PCF filter
for (y = -bound; y <= bound; y += 1.0)
for (x = -bound; x <= bound; x += 1.0) {
clampedpos = vec2(x,y); // screen offset
perspectiveFactor = getDeltaPerspectiveFactor(baseLength + length(clampedpos) * texture_size * radius / bound);
clampedpos = clampedpos * texture_size * perspectiveFactor * radius * perspectiveFactor / bound + smTexCoord.xy; // both dx,dy and radius are adjusted
visibility += getHardShadowColor(shadowsampler, clampedpos.xy, realDistance);
n += 1;
}
return visibility / n;
}
#else
float getShadow(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
{
vec2 clampedpos;
float visibility = 0.0;
float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance, 1.0);
if (radius < 0.1) {
// we are in the middle of even brightness, no need for filtering
return getHardShadow(shadowsampler, smTexCoord.xy, realDistance);
}
float baseLength = getBaseLength(smTexCoord);
float perspectiveFactor;
float texture_size = 1.0 / (f_textureresolution * 0.5);
float y, x;
float bound = clamp(PCFBOUND * (1 - baseLength), PCFBOUND / 2, PCFBOUND);
int n = 0;
// basic PCF filter
for (y = -bound; y <= bound; y += 1.0)
for (x = -bound; x <= bound; x += 1.0) {
clampedpos = vec2(x,y); // screen offset
perspectiveFactor = getDeltaPerspectiveFactor(baseLength + length(clampedpos) * texture_size * radius / bound);
clampedpos = clampedpos * texture_size * perspectiveFactor * radius * perspectiveFactor / bound + smTexCoord.xy; // both dx,dy and radius are adjusted
visibility += getHardShadow(shadowsampler, clampedpos.xy, realDistance);
n += 1;
}
return visibility / n;
}
#endif
#endif
#endif
#if ENABLE_TONE_MAPPING
/* Hable's UC2 Tone mapping parameters
A = 0.22;
B = 0.30;
C = 0.10;
D = 0.20;
E = 0.01;
F = 0.30;
W = 11.2;
equation used: ((x * (A * x + C * B) + D * E) / (x * (A * x + B) + D * F)) - E / F
*/
vec3 uncharted2Tonemap(vec3 x)
{
return ((x * (0.22 * x + 0.03) + 0.002) / (x * (0.22 * x + 0.3) + 0.06)) - 0.03333;
}
vec4 applyToneMapping(vec4 color)
{
color = vec4(pow(color.rgb, vec3(2.2)), color.a);
const float gamma = 1.6;
const float exposureBias = 5.5;
color.rgb = uncharted2Tonemap(exposureBias * color.rgb);
// Precalculated white_scale from
//vec3 whiteScale = 1.0 / uncharted2Tonemap(vec3(W));
vec3 whiteScale = vec3(1.036015346);
color.rgb *= whiteScale;
return vec4(pow(color.rgb, vec3(1.0 / gamma)), color.a);
}
#endif
void main(void)
{
vec3 color;
vec2 uv = varTexCoord.st;
vec4 base = texture2D(baseTexture, uv).rgba;
#ifdef USE_DISCARD
// If alpha is zero, we can just discard the pixel. This fixes transparency
// on GPUs like GC7000L, where GL_ALPHA_TEST is not implemented in mesa,
// and also on GLES 2, where GL_ALPHA_TEST is missing entirely.
if (base.a == 0.0) {
discard;
}
#endif
color = base.rgb;
vec4 col = vec4(color.rgb * varColor.rgb, 1.0);
#ifdef ENABLE_DYNAMIC_SHADOWS
float shadow_int = 0.0;
vec3 shadow_color = vec3(0.0, 0.0, 0.0);
vec3 posLightSpace = getLightSpacePosition();
float distance_rate = (1 - pow(clamp(2.0 * length(posLightSpace.xy - 0.5),0.0,1.0), 20.0));
float f_adj_shadow_strength = max(adj_shadow_strength-mtsmoothstep(0.9,1.1, posLightSpace.z ),0.0);
if (distance_rate > 1e-7) {
#ifdef COLORED_SHADOWS
vec4 visibility = getShadowColor(ShadowMapSampler, posLightSpace.xy, posLightSpace.z);
shadow_int = visibility.r;
shadow_color = visibility.gba;
#else
shadow_int = getShadow(ShadowMapSampler, posLightSpace.xy, posLightSpace.z);
#endif
shadow_int *= distance_rate;
shadow_int *= 1.0 - nightRatio;
}
if (f_normal_length != 0 && cosLight < 0.035) {
shadow_int = max(shadow_int, min(clamp(1.0-nightRatio, 0.0, 1.0), 1 - clamp(cosLight, 0.0, 0.035)/0.035));
}
shadow_int = 1.0 - (shadow_int * f_adj_shadow_strength);
col.rgb = mix(shadow_color,col.rgb,shadow_int)*shadow_int;
// col.r = 0.5 * clamp(getPenumbraRadius(ShadowMapSampler, posLightSpace.xy, posLightSpace.z, 1.0) / SOFTSHADOWRADIUS, 0.0, 1.0) + 0.5 * col.r;
#endif
#if ENABLE_TONE_MAPPING
col = applyToneMapping(col);
#endif
// Due to a bug in some (older ?) graphics stacks (possibly in the glsl compiler ?),
// the fog will only be rendered correctly if the last operation before the
// clamp() is an addition. Else, the clamp() seems to be ignored.
// E.g. the following won't work:
// float clarity = clamp(fogShadingParameter
// * (fogDistance - length(eyeVec)) / fogDistance), 0.0, 1.0);
// As additions usually come for free following a multiplication, the new formula
// should be more efficient as well.
// Note: clarity = (1 - fogginess)
float clarity = clamp(fogShadingParameter
- fogShadingParameter * length(eyeVec) / fogDistance, 0.0, 1.0);
col = mix(skyBgColor, col, clarity);
col = vec4(col.rgb, base.a);
gl_FragColor = col;
}