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#version 120
//#version 130 // use with version 1
uniform highp float lightStrength;
uniform highp float ambientStrength;
uniform highp float shadowQuality;
uniform highp vec3 color_mdl;
uniform highp sampler2DShadow shadowMap; // use with version 2
//uniform highp sampler2D shadowMap; // use with version 1
varying highp vec4 shadowCoord;
varying highp vec2 UV;
varying highp vec3 position_wrld;
varying highp vec3 normal_cmr;
varying highp vec3 eyeDirection_cmr;
varying highp vec3 lightDirection_cmr;
const highp vec2 poissonDisk[16] = vec2[](vec2(-0.94201624, -0.39906216),
vec2(0.94558609, -0.76890725),
vec2(-0.094184101, -0.92938870),
vec2(0.34495938, 0.29387760),
vec2(-0.91588581, 0.45771432),
vec2(-0.81544232, -0.87912464),
vec2(-0.38277543, 0.27676845),
vec2(0.97484398, 0.75648379),
vec2(0.44323325, -0.97511554),
vec2(0.53742981, -0.47373420),
vec2(-0.26496911, -0.41893023),
vec2(0.79197514, 0.19090188),
vec2(-0.24188840, 0.99706507),
vec2(-0.81409955, 0.91437590),
vec2(0.19984126, 0.78641367),
vec2(0.14383161, -0.14100790));
/*const highp vec2 poissonDisk[16] = vec2[](vec2(-0.25, -0.25),
vec2(0.25, -0.25),
vec2(-0.25, 0.25),
vec2(0.25, 0.25),
vec2(-0.5, -0.5),
vec2(0.5, -0.5),
vec2(-0.5, 0.5),
vec2(0.5, 0.5),
vec2(-0.75, -0.75),
vec2(0.75, -0.75),
vec2(-0.75, 0.75),
vec2(0.75, 0.75),
vec2(-1.0, -1.0),
vec2(1.0, -1.0),
vec2(-1.0, 1.0),
vec2(1.0, 1.0));*/
/*float random(vec3 seed, int i) {
vec4 seed4 = vec4(seed, i);
float dot_product = dot(seed4, vec4(12.9898, 78.233, 45.164, 94.673));
return fract(sin(dot_product) * 43758.5453);
}*/
// Version 1: Causes self-shadowing, but shadows are smooth
/*void main() {
float shadowFactor = 1.0; // default to '1' meaning "no shadow"
vec4 shadCoordsPD = shadowCoord;
shadCoordsPD.z += 0.005;
shadCoordsPD /= shadowCoord.w;
if (shadowCoord.w <= 0.0) { // ignore negative projection
shadowFactor = 1.0;
} else if (shadCoordsPD.x < 0.0 || shadCoordsPD.y < 0.0) { // outside light frustum, ignore
shadowFactor = 1.0;
} else if (shadCoordsPD.x >= 1.0 || shadCoordsPD.y >= 1.0) { // outside light frustum, ignore
shadowFactor = 1.0;
} else {
// This does not work perfectly. It causes self-shadowing, which we should get rid of.
// Requires at least #version 130
float shadow = 0.0;
shadow += textureProjOffset(shadowMap, shadCoordsPD, ivec2(0, 0));
shadow += textureProjOffset(shadowMap, shadCoordsPD, ivec2(-1, 1));
shadow += textureProjOffset(shadowMap, shadCoordsPD, ivec2(1, 1));
shadow += textureProjOffset(shadowMap, shadCoordsPD, ivec2(-1, -1));
shadow += textureProjOffset(shadowMap, shadCoordsPD, ivec2(1, -1));
shadow *= 0.2;
shadowFactor = shadow;
}
highp vec3 materialDiffuseColor = color_mdl.rgb;
highp vec3 materialAmbientColor = vec3(ambientStrength, ambientStrength, ambientStrength) * materialDiffuseColor;
highp vec3 materialSpecularColor = vec3(1.0, 1.0, 1.0);
highp vec3 n = normalize(normal_cmr);
highp vec3 l = normalize(lightDirection_cmr);
highp float cosTheta = clamp(dot(n, l), 0.0, 1.0);
highp vec3 E = normalize(eyeDirection_cmr);
highp vec3 R = reflect(-l, n);
highp float cosAlpha = clamp(dot(E, R), 0.0, 1.0);
// Shadow strength can be adjusted by using pow(shadowFactor, strength), but it causes self-shadowing issues that need to be solved
gl_FragColor.rgb =
shadowFactor * (materialAmbientColor +
materialDiffuseColor * lightStrength * cosTheta +
materialSpecularColor * lightStrength * pow(cosAlpha, 20));
gl_FragColor.a = 1.0;
}*/
// Version 2: Shadows are a bit rugged (may be fixed with poisson disk?)
void main() {
highp vec3 materialDiffuseColor = color_mdl.rgb;
highp vec3 materialAmbientColor = vec3(ambientStrength, ambientStrength, ambientStrength) * materialDiffuseColor;
highp vec3 materialSpecularColor = vec3(1.0, 1.0, 1.0);
highp vec3 n = normalize(normal_cmr);
highp vec3 l = normalize(lightDirection_cmr);
highp float cosTheta = clamp(dot(n, l), 0.0, 1.0);
highp vec3 E = normalize(eyeDirection_cmr);
highp vec3 R = reflect(-l, n);
highp float cosAlpha = clamp(dot(E, R), 0.0, 1.0);
highp float bias = 0.005 * tan(acos(cosTheta));
bias = clamp(bias, 0.0, 0.01);
vec4 shadCoords = shadowCoord;
shadCoords.z -= bias;
// adjust shadow strength by increasing the multiplier and lowering the addition (their sum must be 1)
// direct method; needs large shadow texture to look good
//highp float visibility = 0.75 * shadow2DProj(shadowMap, shadCoords).r + 0.25;
// poisson disk sampling; smoothes edges
highp float visibility = 0.2;
for (int i = 0; i < 15; i++) {
vec4 shadCoordsPD = shadCoords;
shadCoordsPD.x += cos(poissonDisk[i].x) / shadowQuality;
shadCoordsPD.y += sin(poissonDisk[i].y) / shadowQuality;
visibility += 0.05 * shadow2DProj(shadowMap, shadCoordsPD).r;
}
// stratified poisson; produces noise but hides pixel edges well
/*for (int i = 0; i < 15; i++) {
vec4 shadCoordsPD = shadCoords;
int index = int(16.0 * random(gl_FragCoord.xyy, i));
shadCoordsPD.xy += poissonDisk[index] / 150.0;
visibility += 0.05 * shadow2DProj(shadowMap, shadCoordsPD).r;
}
*/
gl_FragColor.rgb =
visibility * (materialAmbientColor +
materialDiffuseColor * lightStrength * cosTheta +
materialSpecularColor * lightStrength * pow(cosAlpha, 10));
gl_FragColor.a = 1.0;
}
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