OpenSubdiv/examples/paintTest/shader.glsl
2013-03-15 12:39:44 -07:00

325 lines
10 KiB
GLSL

//
// Copyright (C) Pixar. All rights reserved.
//
// This license governs use of the accompanying software. If you
// use the software, you accept this license. If you do not accept
// the license, do not use the software.
//
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// copyright law. A "contribution" is the original software, or
// any additions or changes to the software.
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// contribution under this license.
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// directly on its contribution.
//
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// 3. Conditions and Limitations
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// rights to use any contributor's name, logo, or trademarks.
// (B) If you bring a patent claim against any contributor over
// patents that you claim are infringed by the software, your
// patent license from such contributor to the software ends
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// complete copy of this license with your distribution. If you
// distribute any portion of the software in compiled or object
// code form, you may only do so under a license that complies
// with this license.
// (E) The software is licensed "as-is." You bear the risk of
// using it. The contributors give no express warranties,
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//
vec4 PTexLookup(vec4 patchCoord,
sampler2DArray data,
samplerBuffer packings,
isamplerBuffer pages)
{
vec2 uv = patchCoord.xy;
int faceID = int(patchCoord.w);
int page = texelFetch(pages, faceID).x;
vec4 packing = texelFetch(packings, faceID);
vec3 coords = vec3( packing.x + uv.x * packing.z,
packing.y + uv.y * packing.w,
page);
return texture(data, coords);
}
uniform sampler2DArray textureImage_Data;
uniform samplerBuffer textureImage_Packing;
uniform isamplerBuffer textureImage_Pages;
vec4 displacement(vec4 position, vec3 normal, vec4 patchCoord)
{
float disp = PTexLookup(patchCoord,
textureImage_Data,
textureImage_Packing,
textureImage_Pages).x;
return position + 0.01*vec4(disp * normal, 0);
}
//--------------------------------------------------------------
// Geometry Shader
//--------------------------------------------------------------
#ifdef GEOMETRY_SHADER
layout(triangles) in;
layout(triangle_strip, max_vertices = 3) out;
#define EDGE_VERTS 3
in block {
OutputVertex v;
} input[3];
out block {
OutputVertex v;
} output;
void emit(int index, vec4 position, vec3 normal, vec4 patchCoord)
{
output.v.position = position;
output.v.patchCoord = patchCoord;
output.v.normal = normal;
gl_Position = ProjectionMatrix * output.v.position;
EmitVertex();
}
const float VIEWPORT_SCALE = 1024.0; // XXXdyu
float edgeDistance(vec4 p, vec4 p0, vec4 p1)
{
return VIEWPORT_SCALE *
abs((p.x - p0.x) * (p1.y - p0.y) -
(p.y - p0.y) * (p1.x - p0.x)) / length(p1.xy - p0.xy);
}
void emit(int index, vec4 position, vec3 normal, vec4 patchCoord, vec4 edgeVerts[EDGE_VERTS])
{
output.v.edgeDistance[0] =
edgeDistance(edgeVerts[index], edgeVerts[0], edgeVerts[1]);
output.v.edgeDistance[1] =
edgeDistance(edgeVerts[index], edgeVerts[1], edgeVerts[2]);
output.v.edgeDistance[2] =
edgeDistance(edgeVerts[index], edgeVerts[2], edgeVerts[0]);
emit(index, position, normal, patchCoord);
}
// --------------------------------------
void main()
{
gl_PrimitiveID = gl_PrimitiveIDIn;
vec4 position[3];
vec4 patchCoord[3];
vec3 normal[3];
// patch coords are computed in tessellation shader
patchCoord[0] = input[0].v.patchCoord;
patchCoord[1] = input[1].v.patchCoord;
patchCoord[2] = input[2].v.patchCoord;
#ifdef USE_PTEX_DISPLACEMENT
position[0] = displacement(input[0].v.position, input[0].v.normal, patchCoord[0]);
position[1] = displacement(input[1].v.position, input[1].v.normal, patchCoord[1]);
position[2] = displacement(input[2].v.position, input[2].v.normal, patchCoord[2]);
#else
position[0] = input[0].v.position;
position[1] = input[1].v.position;
position[2] = input[2].v.position;
#endif
normal[0] = input[0].v.normal;
normal[1] = input[1].v.normal;
normal[2] = input[2].v.normal;
#if defined(GEOMETRY_OUT_WIRE) || defined(GEOMETRY_OUT_LINE)
vec4 edgeVerts[EDGE_VERTS];
edgeVerts[0] = ProjectionMatrix * input[0].v.position;
edgeVerts[1] = ProjectionMatrix * input[1].v.position;
edgeVerts[2] = ProjectionMatrix * input[2].v.position;
edgeVerts[0].xy /= edgeVerts[0].w;
edgeVerts[1].xy /= edgeVerts[1].w;
edgeVerts[2].xy /= edgeVerts[2].w;
emit(0, position[0], normal[0], patchCoord[0], edgeVerts);
emit(1, position[1], normal[1], patchCoord[1], edgeVerts);
emit(2, position[2], normal[2], patchCoord[2], edgeVerts);
#else
emit(0, position[0], normal[0], patchCoord[0]);
emit(1, position[1], normal[1], patchCoord[1]);
emit(2, position[2], normal[2], patchCoord[2]);
#endif
EndPrimitive();
}
#endif
//--------------------------------------------------------------
// Fragment Shader
//--------------------------------------------------------------
#ifdef FRAGMENT_SHADER
in block {
OutputVertex v;
} input;
out vec4 outColor;
#define NUM_LIGHTS 2
struct LightSource {
vec4 position;
vec4 ambient;
vec4 diffuse;
vec4 specular;
};
layout(std140) uniform Lighting {
LightSource lightSource[NUM_LIGHTS];
};
uniform vec4 diffuseColor = vec4(1);
uniform vec4 ambientColor = vec4(1);
vec4
lighting(vec4 diffuse, vec3 Peye, vec3 Neye)
{
vec4 color = vec4(0);
for (int i = 0; i < NUM_LIGHTS; ++i) {
vec4 Plight = lightSource[i].position;
vec3 l = (Plight.w == 0.0)
? normalize(Plight.xyz) : normalize(Plight.xyz - Peye);
vec3 n = normalize(Neye);
vec3 h = normalize(l + vec3(0,0,1)); // directional viewer
float d = max(0.0, dot(n, l));
float s = pow(max(0.0, dot(n, h)), 500.0f);
color += lightSource[i].ambient * ambientColor
+ d * lightSource[i].diffuse * diffuse
+ s * lightSource[i].specular;
}
color.a = 1;
return color;
}
#ifdef USE_PTEX_DISPLACEMENT
vec3
perturbNormalFromDisplacement(vec3 position, vec3 normal, vec4 patchCoord)
{
// by Morten S. Mikkelsen
// http://jbit.net/~sparky/sfgrad_bump/mm_sfgrad_bump.pdf
// slightly modified for ptex guttering
vec3 vSigmaS = dFdx(position);
vec3 vSigmaT = dFdy(position);
vec3 vN = normal;
vec3 vR1 = cross(vSigmaT, vN);
vec3 vR2 = cross(vN, vSigmaS);
float fDet = dot(vSigmaS, vR1);
vec2 texDx = dFdx(patchCoord.xy);
vec2 texDy = dFdy(patchCoord.xy);
// limit forward differencing to the width of ptex gutter
const float resolution = 128.0;
float d = (0.5/resolution)/max(length(texDx), length(texDy));
vec4 STll = patchCoord;
vec4 STlr = patchCoord + d * vec4(texDx.x, texDx.y, 0, 0);
vec4 STul = patchCoord + d * vec4(texDy.x, texDy.y, 0, 0);
float Hll = PTexLookup(STll, textureImage_Data, textureImage_Packing, textureImage_Pages).x;
float Hlr = PTexLookup(STlr, textureImage_Data, textureImage_Packing, textureImage_Pages).x;
float Hul = PTexLookup(STul, textureImage_Data, textureImage_Packing, textureImage_Pages).x;
float dBs = (Hlr - Hll)/d;
float dBt = (Hul - Hll)/d;
vec3 vSurfGrad = sign(fDet) * (dBs * vR1 + dBt * vR2);
return normalize(abs(fDet) * vN - vSurfGrad);
}
#endif // USE_PTEX_NORMAL
vec4
edgeColor(vec4 Cfill, vec4 edgeDistance)
{
#if defined(GEOMETRY_OUT_WIRE) || defined(GEOMETRY_OUT_LINE)
float d =
min(input.v.edgeDistance[0], min(input.v.edgeDistance[1], input.v.edgeDistance[2]));
vec4 Cedge = vec4(0.5, 0.5, 0.5, 1.0);
float p = exp2(-2 * d * d);
#if defined(GEOMETRY_OUT_WIRE)
if (p < 0.25) discard;
#endif
Cfill.rgb = mix(Cfill.rgb, Cedge.rgb, p);
#endif
return Cfill;
}
void
main()
{
vec3 N = (gl_FrontFacing ? input.v.normal : -input.v.normal);
#ifdef USE_PTEX_DISPLACEMENT
N = perturbNormalFromDisplacement(input.v.position.xyz,
N,
input.v.patchCoord);
#endif
vec4 Cf = vec4(1.0);
#if defined(GEOMETRY_OUT_WIRE) || defined(GEOMETRY_OUT_LINE)
Cf = edgeColor(Cf, input.v.edgeDistance);
#endif
#ifdef USE_PTEX_COLOR
Cf = Cf * (vec4(1) - vec4(PTexLookup(input.v.patchCoord,
textureImage_Data,
textureImage_Packing,
textureImage_Pages).x));
#endif
Cf = lighting(Cf, input.v.position.xyz, N);
outColor = Cf;
}
#endif