1 files changed, 147 insertions, 0 deletions
diff --git a/src/datavis3d/engine/shaders/fragmentShadowNoTex b/src/datavis3d/engine/shaders/fragmentShadowNoTex
new file mode 100644
index 00000000..a08b6b40
--- /dev/null
+++ b/src/datavis3d/engine/shaders/fragmentShadowNoTex
@@ -0,0 +1,147 @@
+#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;
+}