Shadow support for surface

Task-number: QTRD-2266

Change-Id: I99fd7a6eda570df3d114ab10a1b07c22736cc86c
Reviewed-by: Tomi Korpipää <tomi.korpipaa@digia.com>

1 files changed, 70 insertions, 0 deletions

diff --git a/src/datavisualization/engine/shaders/surfaceShadowFlat.frag b/src/datavisualization/engine/shaders/surfaceShadowFlat.frag
new file mode 100644
index 00000000..a426b01e
--- /dev/null
+++ b/src/datavisualization/engine/shaders/surfaceShadowFlat.frag
@@ -0,0 +1,70 @@
+#version 120
+
+#extension GL_EXT_gpu_shader4 : require
+
+varying highp vec3 coords_mdl;
+varying highp vec3 position_wrld;
+flat varying highp vec3 normal_cmr;
+varying highp vec3 eyeDirection_cmr;
+varying highp vec3 lightDirection_cmr;
+
+uniform highp sampler2DShadow shadowMap;
+uniform sampler2D textureSampler;
+varying highp vec4 shadowCoord;
+uniform highp vec3 lightPosition_wrld;
+uniform highp float lightStrength;
+uniform highp float ambientStrength;
+uniform highp float shadowQuality;
+
+highp vec2 poissonDisk[16] = vec2[16](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));
+
+void main() {
+    highp vec2 gradientUV = vec2(0.0, (coords_mdl.y + 1.001) / 2.0); // 1000 pixel texture, we need a margin for 1/1000 rounding error
+    highp vec3 materialDiffuseColor = texture2D(textureSampler, gradientUV).xyz;
+    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;
+
+    highp float visibility = 0.6;
+    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 += 0.025 * shadow2DProj(shadowMap, shadCoordsPD).r;
+    }
+
+    gl_FragColor.rgb =
+        visibility * (materialAmbientColor +
+        materialDiffuseColor * lightStrength * cosTheta +
+        materialSpecularColor * lightStrength * pow(cosAlpha, 10));
+    gl_FragColor.a = 1.0;
+}
+