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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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75
examples/TinyRenderer/our_gl.cpp
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@@ -70,6 +70,80 @@ Vec3f barycentric(Vec2f A, Vec2f B, Vec2f C, Vec2f P) {
return Vec3f(-1,1,1); // in this case generate negative coordinates, it will be thrown away by the rasterizator
}
void triangleClipped(mat<4,3,float> &clipc, mat<4,3,float> &orgClipc, IShader &shader, TGAImage &image, float *zbuffer, const Matrix& viewPortMatrix)
{
triangleClipped(clipc, orgClipc,shader,image,zbuffer,0,viewPortMatrix,0);
}
void triangleClipped(mat<4,3,float> &clipc, mat<4,3,float> &orgClipc, IShader &shader, TGAImage &image, float *zbuffer, int* segmentationMaskBuffer, const Matrix& viewPortMatrix, int objectIndex)
{
mat<3,4,float> screenSpacePts = (viewPortMatrix*clipc).transpose(); // transposed to ease access to each of the points
mat<3,2,float> pts2;
for (int i=0; i<3; i++)
{
pts2[i] = proj<2>(screenSpacePts[i]/screenSpacePts[i][3]);
}
Vec2f bboxmin( std::numeric_limits<float>::max(), std::numeric_limits<float>::max());
Vec2f bboxmax(-std::numeric_limits<float>::max(), -std::numeric_limits<float>::max());
Vec2f clamp(image.get_width()-1, image.get_height()-1);
for (int i=0; i<3; i++) {
for (int j=0; j<2; j++) {
bboxmin[j] = b3Max(0.f, b3Min(bboxmin[j], pts2[i][j]));
bboxmax[j] = b3Min(clamp[j], b3Max(bboxmax[j], pts2[i][j]));
}
}
Vec2i P;
TGAColor color;
mat<3,4,float> orgScreenSpacePts = (viewPortMatrix*orgClipc).transpose(); // transposed to ease access to each of the points
mat<3,2,float> orgPts2;
for (int i=0; i<3; i++)
{
orgPts2[i] = proj<2>(orgScreenSpacePts[i]/orgScreenSpacePts[i][3]);
}
for (P.x=bboxmin.x; P.x<=bboxmax.x; P.x++) {
for (P.y=bboxmin.y; P.y<=bboxmax.y; P.y++)
{
float frag_depth = 0;
{
Vec3f bc_screen = barycentric(pts2[0], pts2[1], pts2[2], P);
Vec3f bc_clip = Vec3f(bc_screen.x/screenSpacePts[0][3], bc_screen.y/screenSpacePts[1][3], bc_screen.z/screenSpacePts[2][3]);
bc_clip = bc_clip/(bc_clip.x+bc_clip.y+bc_clip.z);
frag_depth = -1*(clipc[2]*bc_clip);
if (bc_screen.x<0 || bc_screen.y<0 || bc_screen.z<0 ||
zbuffer[P.x+P.y*image.get_width()]>frag_depth)
continue;
}
Vec3f bc_screen2 = barycentric(orgPts2[0], orgPts2[1], orgPts2[2], P);
Vec3f bc_clip2 = Vec3f(bc_screen2.x/orgScreenSpacePts[0][3], bc_screen2.y/orgScreenSpacePts[1][3], bc_screen2.z/orgScreenSpacePts[2][3]);
bc_clip2 = bc_clip2/(bc_clip2.x+bc_clip2.y+bc_clip2.z);
float frag_depth2 = -1*(orgClipc[2]*bc_clip2);
bool discard = shader.fragment(bc_clip2, color);
if (!discard) {
zbuffer[P.x+P.y*image.get_width()] = frag_depth;
if (segmentationMaskBuffer)
{
segmentationMaskBuffer[P.x+P.y*image.get_width()] = objectIndex;
}
image.set(P.x, P.y, color);
}
}
}
}
void triangle(mat<4,3,float> &clipc, IShader &shader, TGAImage &image, float *zbuffer, const Matrix& viewPortMatrix)
{
triangle(clipc,shader,image,zbuffer,0,viewPortMatrix,0);
@@ -119,4 +193,3 @@ void triangle(mat<4,3,float> &clipc, IShader &shader, TGAImage &image, float *zb
}
}
}