#include #include #include #include "our_gl.h" #include "Bullet3Common/b3MinMax.h" namespace TinyRender { IShader::~IShader() {} Matrix viewport(int x, int y, int w, int h) { Matrix Viewport; Viewport = Matrix::identity(); Viewport[0][3] = x + w / 2.f; Viewport[1][3] = y + h / 2.f; Viewport[2][3] = .5f; Viewport[0][0] = w / 2.f; Viewport[1][1] = h / 2.f; Viewport[2][2] = .5f; return Viewport; } Matrix projection(float coeff) { Matrix Projection; Projection = Matrix::identity(); Projection[3][2] = coeff; return Projection; } Matrix lookat(Vec3f eye, Vec3f center, Vec3f up) { Vec3f f = (center - eye).normalize(); Vec3f u = up.normalize(); Vec3f s = cross(f, u).normalize(); u = cross(s, f); Matrix ModelView; ModelView[0][0] = s.x; ModelView[0][1] = s.y; ModelView[0][2] = s.z; ModelView[1][0] = u.x; ModelView[1][1] = u.y; ModelView[1][2] = u.z; ModelView[2][0] = -f.x; ModelView[2][1] = -f.y; ModelView[2][2] = -f.z; ModelView[3][0] = 0.f; ModelView[3][1] = 0.f; ModelView[3][2] = 0.f; ModelView[0][3] = -(s[0] * eye[0] + s[1] * eye[1] + s[2] * eye[2]); ModelView[1][3] = -(u[0] * eye[0] + u[1] * eye[1] + u[2] * eye[2]); ModelView[2][3] = f[0] * eye[0] + f[1] * eye[1] + f[2] * eye[2]; ModelView[3][3] = 1.f; return ModelView; } Vec3f barycentric(Vec2f A, Vec2f B, Vec2f C, Vec2f P) { Vec3f s[2]; for (int i = 2; i--;) { s[i][0] = C[i] - A[i]; s[i][1] = B[i] - A[i]; s[i][2] = A[i] - P[i]; } Vec3f u = cross(s[0], s[1]); if (std::abs(u[2]) > 1e-2) // dont forget that u[2] is integer. If it is zero then triangle ABC is degenerate return Vec3f(1.f - (u.x + u.y) / u.z, u.y / u.z, u.x / u.z); 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 objectAndLinkIndex) { 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::max(), std::numeric_limits::max()); Vec2f bboxmax(-std::numeric_limits::max(), -std::numeric_limits::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()] = objectAndLinkIndex; } 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); } void triangle(mat<4, 3, float> &clipc, IShader &shader, TGAImage &image, float *zbuffer, int *segmentationMaskBuffer, const Matrix &viewPortMatrix, int objectAndLinkIndex) { mat<3, 4, float> pts = (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>(pts[i] / pts[i][3]); Vec2f bboxmin(std::numeric_limits::max(), std::numeric_limits::max()); Vec2f bboxmax(-std::numeric_limits::max(), -std::numeric_limits::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; for (P.x = bboxmin.x; P.x <= bboxmax.x; P.x++) { for (P.y = bboxmin.y; P.y <= bboxmax.y; P.y++) { Vec3f bc_screen = barycentric(pts2[0], pts2[1], pts2[2], P); Vec3f bc_clip = Vec3f(bc_screen.x / pts[0][3], bc_screen.y / pts[1][3], bc_screen.z / pts[2][3]); bc_clip = bc_clip / (bc_clip.x + bc_clip.y + bc_clip.z); float 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; bool discard = shader.fragment(bc_clip, color); if (frag_depth < -shader.m_farPlane) discard = true; if (frag_depth > shader.m_nearPlane) discard = true; if (!discard) { zbuffer[P.x + P.y * image.get_width()] = frag_depth; if (segmentationMaskBuffer) { segmentationMaskBuffer[P.x + P.y * image.get_width()] = objectAndLinkIndex; } image.set(P.x, P.y, color); } } } } }