完成加载obj输出三角面片

tinyrender/CMakeLists.txt

@@ -3,7 +3,7 @@
 #
 
 # 将源代码添加到此项目的可执行文件。
-add_executable (tinyrender "main.cpp" "tgaimage.h" "tgaimage.cpp")
+add_executable (tinyrender "main.cpp" "tgaimage.h" "tgaimage.cpp" "objLoader.h" "objLoader.cpp" "geometry.h")
 
 if (CMAKE_VERSION VERSION_GREATER 3.12)
   set_property(TARGET tinyrender PROPERTY CXX_STANDARD 20)

tinyrender/geometry.h

@@ -0,0 +1,73 @@
+#pragma once
+#ifndef _GEOMETRY_H_
+#define _GEOMETRY_H_
+
+#include <cmath>
+#include <ostream>
+
+
+template <class t> struct Vec2 
+{
+	union 
+	{
+		struct 
+		{
+			t u, v;
+		};
+		struct 
+		{
+			t x, y;
+		};
+		t raw[2];
+	};
+	Vec2(): u(0),v(0){}
+	Vec2(t _u,t _v):u(_u),v(_v){}
+	inline Vec2<t> operator + (const Vec2<t>& V) const { return Vec2<t>(u + V.u, v + V.v); }
+	inline Vec2<t> operator - (const Vec2<t>& V) const { return Vec2<t>(u - V.u, v - V.v); }
+	inline Vec2<t> operator * (float f) const { return Vec2<t>(u * f, v * f); }
+	template <class> friend std::ostream& operator<< (std::ostream& s, Vec2<t>& v);
+};
+
+template <class t> struct Vec3
+{
+	union
+	{
+		struct
+		{
+			t x,y,z ;
+		};
+		struct
+		{
+			t ivert, iuv, inorm;
+		};
+		t raw[3];
+	};
+	Vec3() : x(0), y(0),z(0) {}
+	Vec3(t _x, t _y,t _z) :x(_x), y(_y),z(_z) {}
+	inline Vec3<t> operator ^ (const Vec3<t>& v) const { return Vec3<t>(y * v.z - z * v.y, z * v.x - x * v.z, x * v.y - y * v.x); }
+	inline Vec3<t> operator - (const Vec3<t>& v) const { return Vec3<t>(x - v.x, y - v.y,z-v.z); }
+	inline Vec3<t> operator + (const Vec3<t>& v) const { return Vec3<t>(x + v.x, y + v.y, z + v.z); }
+	inline Vec3<t> operator * (float f) const { return Vec3<t>(x * f, y * f,z * f); }
+	inline t operator *(const Vec3<t>& v) const { return x * v.x + y * v.y + z * v.z; }
+	float norm() const { return std::sqrt(x * x + y * y + z * z); }
+	Vec3<t>& normalize(t l = 1) { *this = (*this) * (l / norm()); return *this; }
+	template <class> friend std::ostream& operator<< (std::ostream& s, Vec3<t>& v);
+};
+
+typedef Vec2<float> Vec2f;
+typedef Vec2<int> Vec2i;
+typedef Vec3<float> Vec3f;
+typedef Vec3<int> Vec3i;
+
+
+template <class t> std::ostream& operator<<(std::ostream& s, Vec2<t>& v) {
+	s << "(" << v.x << ", " << v.y << ")\n";
+	return s;
+}
+
+template <class t> std::ostream& operator<<(std::ostream& s, Vec3<t>& v) {
+	s << "(" << v.x << ", " << v.y << ","<< v.z << ")\n";
+	return s;
+}
+
+#endif // _GEOMETRY_H_

tinyrender/main.cpp

@@ -1,7 +1,11 @@
 #include "tgaimage.h"
+#include "objLoader.h"
 
 const TGAColor white = TGAColor(255, 255, 255, 255);
 const TGAColor red = TGAColor(255, 0, 0, 255);
+objModel* model = NULL;
+const int height = 800;
+const int width = 800;
 
 
 void line(int x0, int y0, int x1, int y1, TGAImage& image, TGAColor color) {
@@ -17,13 +21,11 @@ void line(int x0, int y0, int x1, int y1, TGAImage& image, TGAColor color) {
 		std::swap(x0, x1);
 		std::swap(y0, y1);
 	}
-	int dx = x1 - x0;
-	int dy = y1 - y0;
-	int derror2 = std::abs(dy) * 2;
-	int error2 = 0;
-	int y = y0;
+
 	for (int x = x0; x <=x1; x++)
 	{
+		float t = (x - x0) / (float)(x1 - x0);
+		int y = y0 * (1. - t) + y1 * t;
 		if (steep) 
 		{
 			image.set(y, x, color);
@@ -32,28 +34,38 @@ void line(int x0, int y0, int x1, int y1, TGAImage& image, TGAColor color) {
 		{
 			image.set(x, y, color);
 		}
-		error2 += derror2;
-
-		if (error2 > dx) // 误差值，提供从当前位置到最佳直线的距离
-		{
-			y += (y1 > y0 ? 1 : -1);
-			error2 -= dx * 2;
-		}
 	}
 }
 
 
 int main(int argc, char** argv) {
-	TGAImage image(100, 100, TGAImage::RGB);
-	for (int i = 0; i < 1000000; i++)
+	if (2==argc)
 	{
-		line(13, 20, 80, 40, image, white);
-		line(20, 13, 40, 80, image, red);
-		line(80, 40, 13, 20, image, red);
+		model = new objModel(argv[1]);
+	}
+	else
+	{
+		model = new	objModel("obj/african_head.obj");
+	}
+	TGAImage image(width, height, TGAImage::RGB);
+	for (int i = 0; i < model->nfaces(); i++)
+	{
+		std::vector<int> face = model->face(i);
+		for (int j = 0; j < 3; j++)
+		{
+			Vec3f v0 = model->vert(face[j]);
+			Vec3f v1 = model->vert(face[(j + 1) % 3]);
+			int x0 = (v0.x + 1.) * width / 2.;
+			int y0 = (v0.y + 1.) * height / 2.;
+			int x1 = (v1.x + 1.) * width / 2.;
+			int y1 = (v1.y + 1.) * height / 2.;
+			line(x0, y0, x1, y1, image, white);
+		}
 	}
 	
 	image.flip_vertically(); // i want to have the origin at the left bottom corner of the image
 	image.write_tga_file("output.tga");
+	delete model;
 	return 0;
 }
 

tinyrender/objLoader.cpp

@@ -0,0 +1,74 @@
+#include <vector>
+#include <string>
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include "objLoader.h"
+
+objModel::objModel(const char* filename) : verts_(), faces_() {
+
+	std::cout << "model loading" << std::endl;
+	std::ifstream in;
+	in.open(filename, std::ifstream::in);
+	if (in.fail())
+	{
+		std::cout << "fail"<<std::endl;
+		return;
+	}
+	std::string line;
+	while (!in.eof())
+	{
+		std::getline(in, line);
+		std::istringstream iss(line.c_str());
+		char trash;
+		if (!line.compare(0, 2, "v "))
+		{
+			
+			iss >> trash;
+			Vec3f v;
+			for (int i = 0; i < 3; i++)
+			{
+				iss >> v.raw[i];
+			}
+			verts_.push_back(v);
+		}
+		else if(!line.compare(0,2,"f "))
+		{
+			std::vector<int> f;
+			int itrash, idx;
+			iss >> trash;
+			while (iss >> idx >> trash >> itrash >> trash >> itrash)
+			{
+				idx--;
+				f.push_back(idx);
+			}
+			faces_.push_back(f);
+		}
+
+	}
+	std::cout << "vector size: " << verts_.size() << " \nface size: " << faces_.size() << std::endl;
+
+}
+
+objModel::~objModel() {
+
+}
+
+int objModel::nfaces() {
+	return (int)faces_.size();
+
+}
+
+int objModel::nverts() {
+	return (int)verts_.size();
+}
+
+std::vector<int> objModel::face(int idx) {
+	return faces_[idx];
+}
+
+Vec3f objModel::vert(int i) {
+	return verts_[i];
+}
+
+

tinyrender/objLoader.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#ifndef _OBJLOADER_H_
+#define _OBJLOADER_H_
+
+#include <vector>
+#include "geometry.h"
+
+class objModel
+{
+public:
+	objModel(const char* filename);
+	~objModel();
+	int nverts();
+	int nfaces();
+	Vec3f vert(int i);
+	std::vector<int> face(int idx);
+
+
+
+private:
+	std::vector<Vec3f> verts_;
+	std::vector<std::vector<int>> faces_;
+};
+
+
+
+#endif