73 lines
2.3 KiB
C++
73 lines
2.3 KiB
C++
#include "util_renderer.h"
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#include "util_window.h"
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IShader::~IShader() {}
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float* z_buffer = new float[screen_width * screen_height];
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void viewport(int x, int y, int w, int h, int far_plane, int near_plane) {
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ViewPort[0][3] = x + w / 2.f;
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ViewPort[1][3] = y + h / 2.f;
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ViewPort[2][3] = (far_plane-near_plane) / 2.f;
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ViewPort[0][0] = w / 2.f;
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ViewPort[1][1] = h / 2.f;
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ViewPort[2][2] = (far_plane+near_plane) / 2.f;
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}
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int color_to_int(TGAColor col) {
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return (col[2] << 16) | (col[1] << 8) | col[0];
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}
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Vec3f barycentric(Vec3f* pts, Vec3f P)
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{
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Vec3f u = cross(
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Vec3f(pts[2][0] - pts[0][0], pts[1][0] - pts[0][0], pts[0][0] - P[0]), // AC_x, AB_x, distance_x
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Vec3f(pts[2][1] - pts[0][1], pts[1][1] - pts[0][1], pts[0][1] - P[1]) // AC_y, AB_y, distance_y
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);
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if (std::abs(u[2]) < 1) return Vec3f(-1, 1, 1);
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return Vec3f(1.f - (u.x + u.y) / u.z, u.y / u.z, u.x / u.z);
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}
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void triangle( Vec4f* pts, IShader &shader)
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{
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Vec3f pts3[3];
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for (int i = 0; i < 3; i++)
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pts3[i] = Vec3f(pts[i]);
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if (pts3[0].y == pts3[1].y && pts3[0].y == pts3[2].y) return; // i dont care about degenerate triangles
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//if (pts3[0].y > pts3[1].y) { std::swap(pts3[0], pts3[1]); }
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//if (pts3[0].y > pts3[2].y) { std::swap(pts3[0], pts3[2]); }
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//if (pts3[1].y > pts3[2].y) { std::swap(pts3[1], pts3[2]); }
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Vec2i bounding_box_min(screen_width - 1, screen_height - 1);
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Vec2i bounding_box_max(0, 0);
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Vec2i clamp(screen_width - 1, screen_height - 1);
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#pragma omp parallel for
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for (int i = 0; i < 3; i++)
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for (int j = 0; j < 2; j++) {
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bounding_box_min[j] = std::fmax(0, std::fmin(bounding_box_min[j], (int)pts3[i][j]));
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bounding_box_max[j] = std::fmin(clamp[j], std::fmax(bounding_box_max[j], (int)pts3[i][j]));
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}
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Vec3i P;
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#pragma omp parallel for
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for (P.x = bounding_box_min.x; P.x <= bounding_box_max.x; P.x++) {
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for (P.y = bounding_box_min.y; P.y <= bounding_box_max.y; P.y++) {
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Vec3f bc_coord = barycentric(pts3, P);
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float frag_depth = 0;
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for (int i = 0; i < 3; i++)
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frag_depth += pts3[i][2] * bc_coord[i];
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if (bc_coord.x < 0 || bc_coord.y < 0 || bc_coord.z < 0 || z_buffer[ P.x + P.y * screen_width ]>frag_depth || frag_depth < 0) continue;
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TGAColor color;
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bool discard = shader.fragment(bc_coord, color);
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if (!discard) {
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z_buffer[P.x + P.y * screen_width] = frag_depth;
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set_pixel(P.x, P.y, color_to_int(color));
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}
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}
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}
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} |