bugfix: fix view port transform matrix error, it's for resolution not the projection space.

src/main.cc

@@ -40,7 +40,7 @@ int main(int argc, char *argv[]) {
     const auto &color_image =
         renderer.render(resolution_width, resolution_height);
     cv::imshow("MinusRenderer", color_image);
-  } while (cv::waitKey(25) == -1);
+  } while (cv::waitKey(40) == -1);
   cv::destroyWindow("MinusRenderer");
 
   return 0;

src/minus_renderer.cc

@@ -2,7 +2,6 @@
 // Author: tianlei.richard@qq.com (tianlei.richard)
 
 #include <cmath>
-#include <iostream>
 
 #include "minus_renderer.h"
 #include "rasterizer.h"
@@ -36,13 +35,10 @@ TransformMatrix MinusRenderer::squish_tranform() {
 }
 
 TransformMatrix MinusRenderer::orthographic_tranform() {
-
   const auto right = width_ * 0.5;
   const auto left = -right;
   const auto top = height_ * 0.5;
   const auto bottom = -top;
-  spdlog::info("near: {}, far: {}, top: {}, bottom: {}, left: {}, right: {}",
-               near_, far_, top, bottom, left, right);
 
   TransformMatrix m{{1, 0, 0, -0.5 * (right - left)},
                     {0, 1, 0, -0.5 * (top - bottom)},
@@ -55,13 +51,13 @@ TransformMatrix MinusRenderer::orthographic_tranform() {
                       {0, 0, 0, 1}} *
       m;
 
-  std::cout << m << '\n';
   return m;
 }
 
-TransformMatrix MinusRenderer::view_port_transform() {
-  return TransformMatrix{{width_ * 0.5, 0, 0, width_ * 0.5},
-                         {0, height_ * 0.5, 0, height_ * 0.5},
+TransformMatrix MinusRenderer::view_port_transform(const float width,
+                                                   const float height) {
+  return TransformMatrix{{width * 0.5, 0, 0, width * 0.5},
+                         {0, height * 0.5, 0, height * 0.5},
                          {0, 0, 1, 0},
                          {0, 0, 0, 1}};
 }
@@ -81,7 +77,8 @@ cv::Mat MinusRenderer::render(const int resolution_width,
   for (auto &t : primitives) {
     t.projective_transform(squish_tranform());
     t.affine_transform(orthographic_tranform());
-    t.affine_transform(view_port_transform());
+    t.affine_transform(
+        view_port_transform(resolution_width, resolution_height));
   }
 
   Rasterizer rasterizer{resolution_width, resolution_height};

src/minus_renderer.h

@@ -20,11 +20,12 @@ public:
 private:
   static float calculate_height(const float fov, const float near);
   static float calculate_width(const float height, const float ratio);
+  static TransformMatrix view_port_transform(const float width,
+                                             const float height);
 
 private:
   TransformMatrix squish_tranform();
   TransformMatrix orthographic_tranform();
-  TransformMatrix view_port_transform();
 
 private:
   float near_;

src/rasterizer.cc

@@ -1,12 +1,11 @@
 // Copyright 2024 Bytedance Inc. All Rights Reserved.
 // Author: tianlei.richard@qq.com (tianlei.richard)
 
-#include "rasterizer.h"
-#include "spdlog/fmt/ostr.h" // github.com/gabime/spdlog/issues/1638
-#include "spdlog/spdlog.h"
-#include <iostream>
 #include <limits>
 
+#include "rasterizer.h"
+#include "spdlog/spdlog.h"
+
 Rasterizer::Rasterizer(const int width, const int height)
     : width_(width), height_(height),
       pixels_(std::vector<std::vector<PixelProperty>>(
@@ -19,8 +18,6 @@ std::vector<std::vector<PixelProperty>>
 Rasterizer::rasterize(const std::vector<Triangle> &primitives) {
   for (const auto &t : primitives) {
     const auto &triangle_points = t.get_points<3>();
-    std::cout << "triangle: " << triangle_points[0] << ", "
-              << triangle_points[1] << ", " << triangle_points[2] << '\n';
 
     const auto &aabb = t.axis_align_bbox();
     const int x_min = std::min(std::max(0, aabb.x), width_);
@@ -34,8 +31,6 @@ Rasterizer::rasterize(const std::vector<Triangle> &primitives) {
         auto &property = pixels_[i][j];
         const auto &[is_inside, z_screen] =
             inside(Point2d{j + 0.5, i + 0.5}, t);
-        // spdlog::debug("is_inside: {}, current depth: {}, closest depth: {}",
-        //               is_inside, z_screen, property[3]);
         if (is_inside && z_screen > property[3]) {
           property[0] = 0;
           property[1] = 1;
@@ -53,9 +48,6 @@ std::pair<bool, double> Rasterizer::inside(const Point2d &p_screen,
   const auto points = t.get_points<3>();
 
   const auto plane_normal = t.normal_vector();
-  // spdlog::debug("normal vector: ({},{},{})", plane_normal.x(),
-  // plane_normal.y(),
-  //               plane_normal.z());
   const auto plane_point = points[0];
   const auto z_screen =
       plane_point.z() - (plane_normal.x() * (p_screen.x() - plane_point.x()) +
@@ -75,6 +67,5 @@ std::pair<bool, double> Rasterizer::inside(const Point2d &p_screen,
   const auto r2 = c1.dot(c3);
   const auto r3 = c2.dot(c3);
 
-  // spdlog::debug("r1: {}, r2: {}, r3: {}", r1, r2, r3);
   return {r1 > 0 && r2 > 0 && r3 > 0, z_screen};
 }

src/triangle.cc

@@ -35,12 +35,8 @@ void Triangle::affine_transform(const TransformMatrix &m) {
 }
 
 void Triangle::projective_transform(const TransformMatrix &m) {
-  // std::cout << "triangle: " << points_[0] << ", " << points_[1] << ", "
-  //           << points_[2] << '\n';
   for (auto &p : points_) {
     auto p_homo = m * Eigen::Vector4d(p.x(), p.y(), p.z(), 1.);
-    // std::cout << "triangle: " << p_homo << '\n';
-    // spdlog::info("w: {}", p_homo.w());
     p = (p_homo / p_homo.w()).head<3>();
   }
 }