Add Google IO sample.

samples/GoogleIO-2009/shaders/checker.shader

Index: samples/GoogleIO-2009/shaders/checker.shader
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--- samples/GoogleIO-2009/shaders/checker.shader	(revision 0)
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+/*
+ * Copyright 2009, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+// The 4x4 world view projection matrix.
+float4x4 worldViewProjection : WORLDVIEWPROJECTION;
+float4x4 worldInverseTranspose : WORLDINVERSETRANSPOSE;
+float4x4 world : WORLD;
+
+// light position
+float3 lightWorldPos;
+float3 lightColor;
+
+// input parameters for our vertex shader
+struct VertexShaderInput {
+  float4 position : POSITION;
+  float4 normal : NORMAL;
+  float2 texcoord : TEXCOORD0;
+};
+
+// input parameters for our pixel shader
+struct PixelShaderInput {
+  float4 position : POSITION;
+  float2 texcoord : TEXCOORD0;
+  float3 normal : TEXCOORD1;
+  float3 worldPosition : TEXCOORD2;
+};
+
+// function for getting the checker pattern
+float4 checker(float2 uv) {
+  float checkSize = 10;
+  float fmodResult = fmod(floor(checkSize * uv.x) + floor(checkSize * uv.y),
+                          2.0);
+  return (fmodResult < 1) ?
+      float4(0.4, 0.5, 0.5, 1) :
+      float4(0.6, 0.8, 0.8, 1);
+}
+
+/**
+ * Our vertex shader. In the vertex shader, we calculate the lighting.
+ * Then we'll combine it with our checker pattern input the pixel shader.
+ */
+PixelShaderInput vertexShaderFunction(VertexShaderInput input) {
+  PixelShaderInput output;
+
+  // Transform position into clip space.
+  output.position = mul(input.position, worldViewProjection);
+
+  // Transform normal into world space, where we can do lighting
+  // calculations even if the world transform contains scaling.
+  output.normal = mul(input.normal, worldInverseTranspose).xyz;
+
+  // Calculate surface position in world space.
+  output.worldPosition = mul(input.position, world).xyz;
+
+  output.texcoord = input.texcoord;
+
+  return output;
+}
+
+/**
+ * Our pixel shader. We take the lighting color we got from the vertex sahder
+ * and combine it with our checker pattern. We only need to use the x
+ * coordinate of our input.col because we gave it uniform color
+ */
+float4 pixelShaderFunction(PixelShaderInput input): COLOR {
+  float3 surfaceToLight = normalize(lightWorldPos - input.worldPosition);
+
+  float3 worldNormal = normalize(input.normal);
+
+  // Apply diffuse lighting in world space in case the world transform
+  // contains scaling.
+  float4 check = checker(input.texcoord);
+  float4 directionalIntensity = saturate(dot(worldNormal, surfaceToLight));
+  float4 outColor = directionalIntensity * check;
+  return float4(outColor.rgb, 1);
+}
+
+// Here we tell our effect file *which* functions are
+// our vertex and pixel shaders.
+
+// #o3d VertexShaderEntryPoint vertexShaderFunction
+// #o3d PixelShaderEntryPoint pixelShaderFunction
+// #o3d MatrixLoadOrder RowMajor