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TinyRenderer: implement triangle clipping against near-plane

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TinyRenderer: implement texture UV-repeat by default (instead of clamp(0,1))
This commit is contained in:
Erwin Coumans
2017-04-06 14:31:34 -07:00
parent 0f2771b1d1
commit deb95c758b
5 changed files with 254 additions and 44 deletions
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196
examples/TinyRenderer/TinyRenderer.cpp
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@@ -377,42 +377,91 @@ TinyRenderObjectData::~TinyRenderObjectData()
delete m_model;
}
void TinyRenderer::renderObjectDepth(TinyRenderObjectData& renderData)
static bool equals(const Vec4f& vA, const Vec4f& vB)
{
int width = renderData.m_rgbColorBuffer.get_width();
int height = renderData.m_rgbColorBuffer.get_height();
Vec3f light_dir_local = Vec3f(renderData.m_lightDirWorld[0],renderData.m_lightDirWorld[1],renderData.m_lightDirWorld[2]);
float light_distance = renderData.m_lightDistance;
Model* model = renderData.m_model;
if (0==model)
return;
renderData.m_viewportMatrix = viewport(0,0,width, height);
float* shadowBufferPtr = (renderData.m_shadowBuffer && renderData.m_shadowBuffer->size())?&renderData.m_shadowBuffer->at(0):0;
int* segmentationMaskBufferPtr = 0;
TGAImage depthFrame(width, height, TGAImage::RGB);
{
// light target is set to be the origin, and the up direction is set to be vertical up.
Matrix lightViewMatrix = lookat(light_dir_local*light_distance, Vec3f(0.0,0.0,0.0), Vec3f(0.0,0.0,1.0));
Matrix lightModelViewMatrix = lightViewMatrix*renderData.m_modelMatrix;
Matrix lightViewProjectionMatrix = renderData.m_projectionMatrix;
Vec3f localScaling(renderData.m_localScaling[0],renderData.m_localScaling[1],renderData.m_localScaling[2]);
DepthShader shader(model, lightModelViewMatrix, lightViewProjectionMatrix,renderData.m_modelMatrix, localScaling, light_distance);
for (int i=0; i<model->nfaces(); i++)
{
for (int j=0; j<3; j++) {
shader.vertex(i, j);
}
triangle(shader.varying_tri, shader, depthFrame, shadowBufferPtr, segmentationMaskBufferPtr, renderData.m_viewportMatrix, renderData.m_objectIndex);
}
}
return false;
}
static void clipEdge(const mat<4,3,float>& triangleIn, int vertexIndexA, int vertexIndexB, b3AlignedObjectArray<Vec4f>& vertices)
{
Vec4f v0New = triangleIn.col(vertexIndexA);
Vec4f v1New = triangleIn.col(vertexIndexB);
bool v0Inside = v0New[3] > 0.f && v0New[2] > -v0New[3];
bool v1Inside= v1New[3] > 0.f && v1New[2] > -v1New[3];
if (v0Inside && v1Inside)
{
} else if (v0Inside || v1Inside)
{
float d0 = v0New[2]+v0New[3];
float d1 = v1New[2]+v1New[3];
float factor = 1.0 / (d1-d0);
Vec4f newVertex =(v0New*d1-v1New*d0)*factor;
if (v0Inside)
{
v1New = newVertex;
} else
{
v0New = newVertex;
}
} else
{
return;
}
if (vertices.size()==0 || !(equals(vertices[vertices.size()-1],v0New)))
{
vertices.push_back(v0New);
}
vertices.push_back(v1New);
}
static bool clipTriangleAgainstNearplane(const mat<4,3,float>& triangleIn, b3AlignedObjectArray<mat<4,3,float> >& clippedTrianglesOut)
{
//discard triangle if all vertices are behind near-plane
if (triangleIn[3][0]<0 && triangleIn[3][1] <0 && triangleIn[3][2] <0)
{
return false;
}
//accept triangle if all vertices are in front of the near-plane
if (triangleIn[3][0]>=0 && triangleIn[3][1] >=0 && triangleIn[3][2] >=0)
{
clippedTrianglesOut.push_back(triangleIn);
return false;
}
Vec4f vtxCache[5];
b3AlignedObjectArray<Vec4f> vertices;
vertices.initializeFromBuffer(vtxCache,0,5);
clipEdge(triangleIn,0,1,vertices);
clipEdge(triangleIn,1,2,vertices);
clipEdge(triangleIn,2,0,vertices);
if (vertices.size()<3)
return false;
if (equals(vertices[0],vertices[vertices.size()-1]))
{
vertices.pop_back();
}
//create a fan of triangles
for (int i=1;i<vertices.size()-1;i++)
{
mat<4,3,float>& vtx = clippedTrianglesOut.expand();
vtx.set_col(0,vertices[0]);
vtx.set_col(1,vertices[i]);
vtx.set_col(2,vertices[i+1]);
}
return true;
}
void TinyRenderer::renderObject(TinyRenderObjectData& renderData)
@@ -449,7 +498,82 @@ void TinyRenderer::renderObject(TinyRenderObjectData& renderData)
for (int j=0; j<3; j++) {
shader.vertex(i, j);
}
triangle(shader.varying_tri, shader, frame, &zbuffer[0], segmentationMaskBufferPtr, renderData.m_viewportMatrix, renderData.m_objectIndex);
mat<4,3,float> stackTris[3];
b3AlignedObjectArray< mat<4,3,float> > clippedTriangles;
clippedTriangles.initializeFromBuffer(stackTris,0,3);
bool hasClipped = clipTriangleAgainstNearplane(shader.varying_tri,clippedTriangles);
if (hasClipped)
{
for (int t=0;t<clippedTriangles.size();t++)
{
triangleClipped(clippedTriangles[t], shader.varying_tri, shader, frame, &zbuffer[0], segmentationMaskBufferPtr, renderData.m_viewportMatrix, renderData.m_objectIndex);
}
}
else
{
triangle(shader.varying_tri, shader, frame, &zbuffer[0], segmentationMaskBufferPtr, renderData.m_viewportMatrix, renderData.m_objectIndex);
}
}
}
}
void TinyRenderer::renderObjectDepth(TinyRenderObjectData& renderData)
{
int width = renderData.m_rgbColorBuffer.get_width();
int height = renderData.m_rgbColorBuffer.get_height();
Vec3f light_dir_local = Vec3f(renderData.m_lightDirWorld[0],renderData.m_lightDirWorld[1],renderData.m_lightDirWorld[2]);
float light_distance = renderData.m_lightDistance;
Model* model = renderData.m_model;
if (0==model)
return;
renderData.m_viewportMatrix = viewport(0,0,width, height);
float* shadowBufferPtr = (renderData.m_shadowBuffer && renderData.m_shadowBuffer->size())?&renderData.m_shadowBuffer->at(0):0;
int* segmentationMaskBufferPtr = 0;
TGAImage depthFrame(width, height, TGAImage::RGB);
{
// light target is set to be the origin, and the up direction is set to be vertical up.
Matrix lightViewMatrix = lookat(light_dir_local*light_distance, Vec3f(0.0,0.0,0.0), Vec3f(0.0,0.0,1.0));
Matrix lightModelViewMatrix = lightViewMatrix*renderData.m_modelMatrix;
Matrix lightViewProjectionMatrix = renderData.m_projectionMatrix;
Vec3f localScaling(renderData.m_localScaling[0],renderData.m_localScaling[1],renderData.m_localScaling[2]);
DepthShader shader(model, lightModelViewMatrix, lightViewProjectionMatrix,renderData.m_modelMatrix, localScaling, light_distance);
for (int i=0; i<model->nfaces(); i++)
{
for (int j=0; j<3; j++) {
shader.vertex(i, j);
}
mat<4,3,float> stackTris[3];
b3AlignedObjectArray< mat<4,3,float> > clippedTriangles;
clippedTriangles.initializeFromBuffer(stackTris,0,3);
bool hasClipped = clipTriangleAgainstNearplane(shader.varying_tri,clippedTriangles);
if (hasClipped)
{
for (int t=0;t<clippedTriangles.size();t++)
{
triangleClipped(clippedTriangles[t], shader.varying_tri, shader, depthFrame, shadowBufferPtr, segmentationMaskBufferPtr, renderData.m_viewportMatrix, renderData.m_objectIndex);
}
} else
{
triangle(shader.varying_tri, shader, depthFrame, shadowBufferPtr, segmentationMaskBufferPtr, renderData.m_viewportMatrix, renderData.m_objectIndex);
}
}
}