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1033 lines
65 KiB
1033 lines
65 KiB
/*
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OneLoneCoder.com - 3D Graphics Part #4 - Texturing & Depth Buffers
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"Tredimensjonal Grafikk" - @Javidx9
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!!! MODIFIED TO SUITE PIXEL GAME ENGINE !!!
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!!! EXAMINE LINE 70 BEFORE COMPILING !!!
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License (OLC-3)
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~~~~~~~~~~~~~~~
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Copyright 2018-2019 OneLoneCoder.com
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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1. Redistributions or derivations of source code must retain the above
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copyright notice, this list of conditions and the following disclaimer.
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2. Redistributions or derivative works in binary form must reproduce
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the above copyright notice. This list of conditions and the following
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disclaimer must be reproduced in the documentation and/or other
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materials provided with the distribution.
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3. Neither the name of the copyright holder nor the names of its
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contributors may be used to endorse or promote products derived
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from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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Background
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~~~~~~~~~~
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3D Graphics is an interesting, visually pleasing suite of algorithms. This is the
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first video in a series that will demonstrate the fundamentals required to
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build your own software based 3D graphics systems.
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Video
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~~~~~
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https://youtu.be/ih20l3pJoeU
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https://youtu.be/XgMWc6LumG4
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https://youtu.be/HXSuNxpCzdM
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https://youtu.be/nBzCS-Y0FcY
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Author
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~~~~~~
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Twitter: @javidx9
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Blog: http://www.onelonecoder.com
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Discord: https://discord.gg/WhwHUMV
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Last Updated: 26/05/2019
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*/
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// PLEASE NOTE! The video shows the Spyro The Dragon Level - I can't redistribute that
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// so this file is configured to show the textured Jario cube. Please ensure you have
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// downloaded the "Jario.spr" file from
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// Comment out this line to run "mountains" demo from part 3
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#define DO_TEXTURE_DEMO
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#define OLC_PGE_APPLICATION
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#include "olcPixelGameEngine.h"
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#include <fstream>
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#include <strstream>
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#include <algorithm>
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#include <string>
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using namespace std;
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// Created a 2D structure to hold texture coordinates
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struct vec2d
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{
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float u = 0;
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float v = 0;
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float w = 1;
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};
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struct vec3d
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{
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float x = 0;
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float y = 0;
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float z = 0;
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float w = 1; // Need a 4th term to perform sensible matrix vector multiplication
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};
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struct triangle
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{
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vec3d p[3];
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vec2d t[3]; // added a texture coord per vertex
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olc::Pixel col;
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};
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struct mesh
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{
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vector<triangle> tris;
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bool LoadFromObjectFile(string sFilename, bool bHasTexture = false)
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{
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ifstream f(sFilename);
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if (!f.is_open())
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return false;
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// Local cache of verts
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vector<vec3d> verts;
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vector<vec2d> texs;
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while (!f.eof())
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{
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char line[128];
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f.getline(line, 128);
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strstream s;
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s << line;
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char junk;
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if (line[0] == 'v')
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{
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if (line[1] == 't')
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{
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vec2d v;
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s >> junk >> junk >> v.u >> v.v;
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// A little hack for the spyro texture
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//v.u = 1.0f - v.u;
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//v.v = 1.0f - v.v;
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texs.push_back(v);
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}
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else
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{
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vec3d v;
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s >> junk >> v.x >> v.y >> v.z;
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verts.push_back(v);
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}
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}
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if (!bHasTexture)
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{
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if (line[0] == 'f')
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{
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int f[3];
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s >> junk >> f[0] >> f[1] >> f[2];
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tris.push_back({ verts[f[0] - 1], verts[f[1] - 1], verts[f[2] - 1] });
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}
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}
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else
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{
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if (line[0] == 'f')
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{
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s >> junk;
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string tokens[6];
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int nTokenCount = -1;
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while (!s.eof())
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{
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char c = s.get();
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if (c == ' ' || c == '/')
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nTokenCount++;
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else
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tokens[nTokenCount].append(1, c);
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}
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tokens[nTokenCount].pop_back();
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tris.push_back({ verts[stoi(tokens[0]) - 1], verts[stoi(tokens[2]) - 1], verts[stoi(tokens[4]) - 1],
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texs[stoi(tokens[1]) - 1], texs[stoi(tokens[3]) - 1], texs[stoi(tokens[5]) - 1] });
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}
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}
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}
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return true;
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}
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};
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struct mat4x4
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{
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float m[4][4] = { 0 };
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};
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class olcEngine3D : public olc::PixelGameEngine
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{
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public:
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olcEngine3D()
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{
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sAppName = "3D Demo";
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}
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private:
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mesh meshCube;
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mat4x4 matProj; // Matrix that converts from view space to screen space
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vec3d vCamera; // Location of camera in world space
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vec3d vLookDir; // Direction vector along the direction camera points
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float fYaw; // FPS Camera rotation in XZ plane
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float fTheta; // Spins World transform
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olc::Sprite *sprTex1;
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vec3d Matrix_MultiplyVector(mat4x4 &m, vec3d &i)
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{
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vec3d v;
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v.x = i.x * m.m[0][0] + i.y * m.m[1][0] + i.z * m.m[2][0] + i.w * m.m[3][0];
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v.y = i.x * m.m[0][1] + i.y * m.m[1][1] + i.z * m.m[2][1] + i.w * m.m[3][1];
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v.z = i.x * m.m[0][2] + i.y * m.m[1][2] + i.z * m.m[2][2] + i.w * m.m[3][2];
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v.w = i.x * m.m[0][3] + i.y * m.m[1][3] + i.z * m.m[2][3] + i.w * m.m[3][3];
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return v;
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}
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mat4x4 Matrix_MakeIdentity()
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{
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mat4x4 matrix;
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matrix.m[0][0] = 1.0f;
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matrix.m[1][1] = 1.0f;
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matrix.m[2][2] = 1.0f;
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matrix.m[3][3] = 1.0f;
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return matrix;
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}
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mat4x4 Matrix_MakeRotationX(float fAngleRad)
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{
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mat4x4 matrix;
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matrix.m[0][0] = 1.0f;
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matrix.m[1][1] = cosf(fAngleRad);
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matrix.m[1][2] = sinf(fAngleRad);
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matrix.m[2][1] = -sinf(fAngleRad);
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matrix.m[2][2] = cosf(fAngleRad);
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matrix.m[3][3] = 1.0f;
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return matrix;
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}
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mat4x4 Matrix_MakeRotationY(float fAngleRad)
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{
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mat4x4 matrix;
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matrix.m[0][0] = cosf(fAngleRad);
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matrix.m[0][2] = sinf(fAngleRad);
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matrix.m[2][0] = -sinf(fAngleRad);
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matrix.m[1][1] = 1.0f;
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matrix.m[2][2] = cosf(fAngleRad);
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matrix.m[3][3] = 1.0f;
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return matrix;
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}
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mat4x4 Matrix_MakeRotationZ(float fAngleRad)
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{
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mat4x4 matrix;
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matrix.m[0][0] = cosf(fAngleRad);
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matrix.m[0][1] = sinf(fAngleRad);
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matrix.m[1][0] = -sinf(fAngleRad);
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matrix.m[1][1] = cosf(fAngleRad);
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matrix.m[2][2] = 1.0f;
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matrix.m[3][3] = 1.0f;
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return matrix;
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}
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mat4x4 Matrix_MakeTranslation(float x, float y, float z)
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{
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mat4x4 matrix;
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matrix.m[0][0] = 1.0f;
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matrix.m[1][1] = 1.0f;
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matrix.m[2][2] = 1.0f;
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matrix.m[3][3] = 1.0f;
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matrix.m[3][0] = x;
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matrix.m[3][1] = y;
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matrix.m[3][2] = z;
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return matrix;
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}
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mat4x4 Matrix_MakeProjection(float fFovDegrees, float fAspectRatio, float fNear, float fFar)
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{
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float fFovRad = 1.0f / tanf(fFovDegrees * 0.5f / 180.0f * 3.14159f);
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mat4x4 matrix;
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matrix.m[0][0] = fAspectRatio * fFovRad;
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matrix.m[1][1] = fFovRad;
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matrix.m[2][2] = fFar / (fFar - fNear);
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matrix.m[3][2] = (-fFar * fNear) / (fFar - fNear);
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matrix.m[2][3] = 1.0f;
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matrix.m[3][3] = 0.0f;
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return matrix;
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}
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mat4x4 Matrix_MultiplyMatrix(mat4x4 &m1, mat4x4 &m2)
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{
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mat4x4 matrix;
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for (int c = 0; c < 4; c++)
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for (int r = 0; r < 4; r++)
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matrix.m[r][c] = m1.m[r][0] * m2.m[0][c] + m1.m[r][1] * m2.m[1][c] + m1.m[r][2] * m2.m[2][c] + m1.m[r][3] * m2.m[3][c];
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return matrix;
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}
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mat4x4 Matrix_PointAt(vec3d &pos, vec3d &target, vec3d &up)
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{
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// Calculate new forward direction
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vec3d newForward = Vector_Sub(target, pos);
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newForward = Vector_Normalise(newForward);
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// Calculate new Up direction
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vec3d a = Vector_Mul(newForward, Vector_DotProduct(up, newForward));
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vec3d newUp = Vector_Sub(up, a);
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newUp = Vector_Normalise(newUp);
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// New Right direction is easy, its just cross product
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vec3d newRight = Vector_CrossProduct(newUp, newForward);
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// Construct Dimensioning and Translation Matrix
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mat4x4 matrix;
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matrix.m[0][0] = newRight.x; matrix.m[0][1] = newRight.y; matrix.m[0][2] = newRight.z; matrix.m[0][3] = 0.0f;
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matrix.m[1][0] = newUp.x; matrix.m[1][1] = newUp.y; matrix.m[1][2] = newUp.z; matrix.m[1][3] = 0.0f;
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matrix.m[2][0] = newForward.x; matrix.m[2][1] = newForward.y; matrix.m[2][2] = newForward.z; matrix.m[2][3] = 0.0f;
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matrix.m[3][0] = pos.x; matrix.m[3][1] = pos.y; matrix.m[3][2] = pos.z; matrix.m[3][3] = 1.0f;
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return matrix;
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}
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mat4x4 Matrix_QuickInverse(mat4x4 &m) // Only for Rotation/Translation Matrices
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{
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mat4x4 matrix;
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matrix.m[0][0] = m.m[0][0]; matrix.m[0][1] = m.m[1][0]; matrix.m[0][2] = m.m[2][0]; matrix.m[0][3] = 0.0f;
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matrix.m[1][0] = m.m[0][1]; matrix.m[1][1] = m.m[1][1]; matrix.m[1][2] = m.m[2][1]; matrix.m[1][3] = 0.0f;
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matrix.m[2][0] = m.m[0][2]; matrix.m[2][1] = m.m[1][2]; matrix.m[2][2] = m.m[2][2]; matrix.m[2][3] = 0.0f;
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matrix.m[3][0] = -(m.m[3][0] * matrix.m[0][0] + m.m[3][1] * matrix.m[1][0] + m.m[3][2] * matrix.m[2][0]);
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matrix.m[3][1] = -(m.m[3][0] * matrix.m[0][1] + m.m[3][1] * matrix.m[1][1] + m.m[3][2] * matrix.m[2][1]);
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matrix.m[3][2] = -(m.m[3][0] * matrix.m[0][2] + m.m[3][1] * matrix.m[1][2] + m.m[3][2] * matrix.m[2][2]);
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matrix.m[3][3] = 1.0f;
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return matrix;
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}
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vec3d Vector_Add(vec3d &v1, vec3d &v2)
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{
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return { v1.x + v2.x, v1.y + v2.y, v1.z + v2.z };
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}
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vec3d Vector_Sub(vec3d &v1, vec3d &v2)
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{
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return { v1.x - v2.x, v1.y - v2.y, v1.z - v2.z };
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}
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vec3d Vector_Mul(vec3d &v1, float k)
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{
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return { v1.x * k, v1.y * k, v1.z * k };
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}
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vec3d Vector_Div(vec3d &v1, float k)
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{
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return { v1.x / k, v1.y / k, v1.z / k };
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}
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float Vector_DotProduct(vec3d &v1, vec3d &v2)
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{
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return v1.x*v2.x + v1.y*v2.y + v1.z * v2.z;
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}
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float Vector_Length(vec3d &v)
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{
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return sqrtf(Vector_DotProduct(v, v));
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}
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vec3d Vector_Normalise(vec3d &v)
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{
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float l = Vector_Length(v);
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return { v.x / l, v.y / l, v.z / l };
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}
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vec3d Vector_CrossProduct(vec3d &v1, vec3d &v2)
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{
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vec3d v;
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v.x = v1.y * v2.z - v1.z * v2.y;
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v.y = v1.z * v2.x - v1.x * v2.z;
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v.z = v1.x * v2.y - v1.y * v2.x;
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return v;
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}
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vec3d Vector_IntersectPlane(vec3d &plane_p, vec3d &plane_n, vec3d &lineStart, vec3d &lineEnd, float &t)
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{
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plane_n = Vector_Normalise(plane_n);
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float plane_d = -Vector_DotProduct(plane_n, plane_p);
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float ad = Vector_DotProduct(lineStart, plane_n);
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float bd = Vector_DotProduct(lineEnd, plane_n);
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t = (-plane_d - ad) / (bd - ad);
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vec3d lineStartToEnd = Vector_Sub(lineEnd, lineStart);
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vec3d lineToIntersect = Vector_Mul(lineStartToEnd, t);
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return Vector_Add(lineStart, lineToIntersect);
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}
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int Triangle_ClipAgainstPlane(vec3d plane_p, vec3d plane_n, triangle &in_tri, triangle &out_tri1, triangle &out_tri2)
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{
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// Make sure plane normal is indeed normal
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plane_n = Vector_Normalise(plane_n);
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// Return signed shortest distance from point to plane, plane normal must be normalised
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auto dist = [&](vec3d &p)
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{
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vec3d n = Vector_Normalise(p);
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return (plane_n.x * p.x + plane_n.y * p.y + plane_n.z * p.z - Vector_DotProduct(plane_n, plane_p));
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};
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// Create two temporary storage arrays to classify points either side of plane
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// If distance sign is positive, point lies on "inside" of plane
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vec3d* inside_points[3]; int nInsidePointCount = 0;
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vec3d* outside_points[3]; int nOutsidePointCount = 0;
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vec2d* inside_tex[3]; int nInsideTexCount = 0;
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vec2d* outside_tex[3]; int nOutsideTexCount = 0;
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|
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// Get signed distance of each point in triangle to plane
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float d0 = dist(in_tri.p[0]);
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float d1 = dist(in_tri.p[1]);
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float d2 = dist(in_tri.p[2]);
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if (d0 >= 0) { inside_points[nInsidePointCount++] = &in_tri.p[0]; inside_tex[nInsideTexCount++] = &in_tri.t[0]; }
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else {
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outside_points[nOutsidePointCount++] = &in_tri.p[0]; outside_tex[nOutsideTexCount++] = &in_tri.t[0];
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}
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if (d1 >= 0) {
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inside_points[nInsidePointCount++] = &in_tri.p[1]; inside_tex[nInsideTexCount++] = &in_tri.t[1];
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}
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else {
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outside_points[nOutsidePointCount++] = &in_tri.p[1]; outside_tex[nOutsideTexCount++] = &in_tri.t[1];
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}
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if (d2 >= 0) {
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inside_points[nInsidePointCount++] = &in_tri.p[2]; inside_tex[nInsideTexCount++] = &in_tri.t[2];
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}
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else {
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outside_points[nOutsidePointCount++] = &in_tri.p[2]; outside_tex[nOutsideTexCount++] = &in_tri.t[2];
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}
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|
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// Now classify triangle points, and break the input triangle into
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// smaller output triangles if required. There are four possible
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// outcomes...
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if (nInsidePointCount == 0)
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{
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// All points lie on the outside of plane, so clip whole triangle
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// It ceases to exist
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return 0; // No returned triangles are valid
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}
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if (nInsidePointCount == 3)
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{
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// All points lie on the inside of plane, so do nothing
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// and allow the triangle to simply pass through
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out_tri1 = in_tri;
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return 1; // Just the one returned original triangle is valid
|
|
}
|
|
|
|
if (nInsidePointCount == 1 && nOutsidePointCount == 2)
|
|
{
|
|
// Triangle should be clipped. As two points lie outside
|
|
// the plane, the triangle simply becomes a smaller triangle
|
|
|
|
// Copy appearance info to new triangle
|
|
out_tri1.col = in_tri.col;
|
|
|
|
|
|
// The inside point is valid, so keep that...
|
|
out_tri1.p[0] = *inside_points[0];
|
|
out_tri1.t[0] = *inside_tex[0];
|
|
|
|
// but the two new points are at the locations where the
|
|
// original sides of the triangle (lines) intersect with the plane
|
|
float t;
|
|
out_tri1.p[1] = Vector_IntersectPlane(plane_p, plane_n, *inside_points[0], *outside_points[0], t);
|
|
out_tri1.t[1].u = t * (outside_tex[0]->u - inside_tex[0]->u) + inside_tex[0]->u;
|
|
out_tri1.t[1].v = t * (outside_tex[0]->v - inside_tex[0]->v) + inside_tex[0]->v;
|
|
out_tri1.t[1].w = t * (outside_tex[0]->w - inside_tex[0]->w) + inside_tex[0]->w;
|
|
|
|
out_tri1.p[2] = Vector_IntersectPlane(plane_p, plane_n, *inside_points[0], *outside_points[1], t);
|
|
out_tri1.t[2].u = t * (outside_tex[1]->u - inside_tex[0]->u) + inside_tex[0]->u;
|
|
out_tri1.t[2].v = t * (outside_tex[1]->v - inside_tex[0]->v) + inside_tex[0]->v;
|
|
out_tri1.t[2].w = t * (outside_tex[1]->w - inside_tex[0]->w) + inside_tex[0]->w;
|
|
|
|
return 1; // Return the newly formed single triangle
|
|
}
|
|
|
|
if (nInsidePointCount == 2 && nOutsidePointCount == 1)
|
|
{
|
|
// Triangle should be clipped. As two points lie inside the plane,
|
|
// the clipped triangle becomes a "quad". Fortunately, we can
|
|
// represent a quad with two new triangles
|
|
|
|
// Copy appearance info to new triangles
|
|
out_tri1.col = in_tri.col;
|
|
|
|
|
|
out_tri2.col = in_tri.col;
|
|
|
|
|
|
// The first triangle consists of the two inside points and a new
|
|
// point determined by the location where one side of the triangle
|
|
// intersects with the plane
|
|
out_tri1.p[0] = *inside_points[0];
|
|
out_tri1.p[1] = *inside_points[1];
|
|
out_tri1.t[0] = *inside_tex[0];
|
|
out_tri1.t[1] = *inside_tex[1];
|
|
|
|
float t;
|
|
out_tri1.p[2] = Vector_IntersectPlane(plane_p, plane_n, *inside_points[0], *outside_points[0], t);
|
|
out_tri1.t[2].u = t * (outside_tex[0]->u - inside_tex[0]->u) + inside_tex[0]->u;
|
|
out_tri1.t[2].v = t * (outside_tex[0]->v - inside_tex[0]->v) + inside_tex[0]->v;
|
|
out_tri1.t[2].w = t * (outside_tex[0]->w - inside_tex[0]->w) + inside_tex[0]->w;
|
|
|
|
// The second triangle is composed of one of he inside points, a
|
|
// new point determined by the intersection of the other side of the
|
|
// triangle and the plane, and the newly created point above
|
|
out_tri2.p[0] = *inside_points[1];
|
|
out_tri2.t[0] = *inside_tex[1];
|
|
out_tri2.p[1] = out_tri1.p[2];
|
|
out_tri2.t[1] = out_tri1.t[2];
|
|
out_tri2.p[2] = Vector_IntersectPlane(plane_p, plane_n, *inside_points[1], *outside_points[0], t);
|
|
out_tri2.t[2].u = t * (outside_tex[0]->u - inside_tex[1]->u) + inside_tex[1]->u;
|
|
out_tri2.t[2].v = t * (outside_tex[0]->v - inside_tex[1]->v) + inside_tex[1]->v;
|
|
out_tri2.t[2].w = t * (outside_tex[0]->w - inside_tex[1]->w) + inside_tex[1]->w;
|
|
return 2; // Return two newly formed triangles which form a quad
|
|
}
|
|
}
|
|
|
|
|
|
|
|
|
|
float *pDepthBuffer = nullptr;
|
|
|
|
public:
|
|
bool OnUserCreate() override
|
|
{
|
|
|
|
pDepthBuffer = new float[ScreenWidth() * ScreenHeight()];
|
|
|
|
// Load object file
|
|
#ifdef DO_TEXTURE_DEMO
|
|
meshCube.tris = {
|
|
|
|
// SOUTH
|
|
{ 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f,},
|
|
{ 0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f,},
|
|
|
|
// EAST
|
|
{ 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f,},
|
|
{ 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f,},
|
|
|
|
// NORTH
|
|
{ 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f,},
|
|
{ 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f,},
|
|
|
|
// WEST
|
|
{ 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f,},
|
|
{ 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f,},
|
|
|
|
// TOP
|
|
{ 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f,},
|
|
{ 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f,},
|
|
|
|
// BOTTOM
|
|
{ 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f,},
|
|
{ 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f,},
|
|
|
|
};
|
|
#else
|
|
meshCube.LoadFromObjectFile("mountains.obj");
|
|
#endif
|
|
|
|
|
|
sprTex1 = new olc::Sprite("zombie.png");
|
|
|
|
// Projection Matrix
|
|
matProj = Matrix_MakeProjection(90.0f, (float)ScreenHeight() / (float)ScreenWidth(), 0.1f, 1000.0f);
|
|
return true;
|
|
}
|
|
|
|
bool OnUserUpdate(float fElapsedTime) override
|
|
{
|
|
if (GetKey(olc::Key::UP).bHeld)
|
|
vCamera.y += 8.0f * fElapsedTime; // Travel Upwards
|
|
|
|
if (GetKey(olc::Key::DOWN).bHeld)
|
|
vCamera.y -= 8.0f * fElapsedTime; // Travel Downwards
|
|
|
|
|
|
// Dont use these two in FPS mode, it is confusing :P
|
|
if (GetKey(olc::Key::LEFT).bHeld)
|
|
vCamera.x -= 8.0f * fElapsedTime; // Travel Along X-Axis
|
|
|
|
if (GetKey(olc::Key::RIGHT).bHeld)
|
|
vCamera.x += 8.0f * fElapsedTime; // Travel Along X-Axis
|
|
///////
|
|
|
|
|
|
vec3d vForward = Vector_Mul(vLookDir, 8.0f * fElapsedTime);
|
|
|
|
// Standard FPS Control scheme, but turn instead of strafe
|
|
if (GetKey(olc::Key::W).bHeld)
|
|
vCamera = Vector_Add(vCamera, vForward);
|
|
|
|
if (GetKey(olc::Key::S).bHeld)
|
|
vCamera = Vector_Sub(vCamera, vForward);
|
|
|
|
if (GetKey(olc::Key::A).bHeld)
|
|
fYaw -= 2.0f * fElapsedTime;
|
|
|
|
if (GetKey(olc::Key::D).bHeld)
|
|
fYaw += 2.0f * fElapsedTime;
|
|
|
|
|
|
|
|
|
|
// Set up "World Tranmsform" though not updating theta
|
|
// makes this a bit redundant
|
|
mat4x4 matRotZ, matRotX;
|
|
#ifdef DO_TEXTURE_DEMO
|
|
fTheta += 1.0f * fElapsedTime; // Uncomment to spin me right round baby right round
|
|
#endif
|
|
matRotZ = Matrix_MakeRotationZ(fTheta * 0.5f);
|
|
matRotX = Matrix_MakeRotationX(fTheta);
|
|
|
|
mat4x4 matTrans;
|
|
matTrans = Matrix_MakeTranslation(0.0f, 0.0f, 5.0f);
|
|
|
|
mat4x4 matWorld;
|
|
matWorld = Matrix_MakeIdentity(); // Form World Matrix
|
|
matWorld = Matrix_MultiplyMatrix(matRotZ, matRotX); // Transform by rotation
|
|
matWorld = Matrix_MultiplyMatrix(matWorld, matTrans); // Transform by translation
|
|
|
|
// Create "Point At" Matrix for camera
|
|
vec3d vUp = { 0,1,0 };
|
|
vec3d vTarget = { 0,0,1 };
|
|
mat4x4 matCameraRot = Matrix_MakeRotationY(fYaw);
|
|
vLookDir = Matrix_MultiplyVector(matCameraRot, vTarget);
|
|
vTarget = Vector_Add(vCamera, vLookDir);
|
|
mat4x4 matCamera = Matrix_PointAt(vCamera, vTarget, vUp);
|
|
|
|
// Make view matrix from camera
|
|
mat4x4 matView = Matrix_QuickInverse(matCamera);
|
|
|
|
// Store triagles for rastering later
|
|
vector<triangle> vecTrianglesToRaster;
|
|
|
|
// Draw Triangles
|
|
for (auto tri : meshCube.tris)
|
|
{
|
|
triangle triProjected, triTransformed, triViewed;
|
|
|
|
// World Matrix Transform
|
|
triTransformed.p[0] = Matrix_MultiplyVector(matWorld, tri.p[0]);
|
|
triTransformed.p[1] = Matrix_MultiplyVector(matWorld, tri.p[1]);
|
|
triTransformed.p[2] = Matrix_MultiplyVector(matWorld, tri.p[2]);
|
|
triTransformed.t[0] = tri.t[0];
|
|
triTransformed.t[1] = tri.t[1];
|
|
triTransformed.t[2] = tri.t[2];
|
|
|
|
// Calculate triangle Normal
|
|
vec3d normal, line1, line2;
|
|
|
|
// Get lines either side of triangle
|
|
line1 = Vector_Sub(triTransformed.p[1], triTransformed.p[0]);
|
|
line2 = Vector_Sub(triTransformed.p[2], triTransformed.p[0]);
|
|
|
|
// Take cross product of lines to get normal to triangle surface
|
|
normal = Vector_CrossProduct(line1, line2);
|
|
|
|
// You normally need to normalise a normal!
|
|
normal = Vector_Normalise(normal);
|
|
|
|
// Get Ray from triangle to camera
|
|
vec3d vCameraRay = Vector_Sub(triTransformed.p[0], vCamera);
|
|
|
|
// If ray is aligned with normal, then triangle is visible
|
|
if (Vector_DotProduct(normal, vCameraRay) < 0.0f)
|
|
{
|
|
// Illumination
|
|
vec3d light_direction = { 0.0f, 1.0f, -1.0f };
|
|
light_direction = Vector_Normalise(light_direction);
|
|
|
|
// How "aligned" are light direction and triangle surface normal?
|
|
float dp = max(0.1f, Vector_DotProduct(light_direction, normal));
|
|
|
|
// Choose console colours as required (much easier with RGB)
|
|
triTransformed.col = olc::Pixel(dp * 255, dp * 255, dp * 255);
|
|
|
|
|
|
// Convert World Space --> View Space
|
|
triViewed.p[0] = Matrix_MultiplyVector(matView, triTransformed.p[0]);
|
|
triViewed.p[1] = Matrix_MultiplyVector(matView, triTransformed.p[1]);
|
|
triViewed.p[2] = Matrix_MultiplyVector(matView, triTransformed.p[2]);
|
|
triViewed.col = triTransformed.col;
|
|
triViewed.t[0] = triTransformed.t[0];
|
|
triViewed.t[1] = triTransformed.t[1];
|
|
triViewed.t[2] = triTransformed.t[2];
|
|
|
|
// Clip Viewed Triangle against near plane, this could form two additional
|
|
// additional triangles.
|
|
int nClippedTriangles = 0;
|
|
triangle clipped[2];
|
|
nClippedTriangles = Triangle_ClipAgainstPlane({ 0.0f, 0.0f, 0.1f }, { 0.0f, 0.0f, 1.0f }, triViewed, clipped[0], clipped[1]);
|
|
|
|
// We may end up with multiple triangles form the clip, so project as
|
|
// required
|
|
for (int n = 0; n < nClippedTriangles; n++)
|
|
{
|
|
// Project triangles from 3D --> 2D
|
|
triProjected.p[0] = Matrix_MultiplyVector(matProj, clipped[n].p[0]);
|
|
triProjected.p[1] = Matrix_MultiplyVector(matProj, clipped[n].p[1]);
|
|
triProjected.p[2] = Matrix_MultiplyVector(matProj, clipped[n].p[2]);
|
|
triProjected.col = clipped[n].col;
|
|
triProjected.t[0] = clipped[n].t[0];
|
|
triProjected.t[1] = clipped[n].t[1];
|
|
triProjected.t[2] = clipped[n].t[2];
|
|
|
|
|
|
triProjected.t[0].u = triProjected.t[0].u / triProjected.p[0].w;
|
|
triProjected.t[1].u = triProjected.t[1].u / triProjected.p[1].w;
|
|
triProjected.t[2].u = triProjected.t[2].u / triProjected.p[2].w;
|
|
|
|
triProjected.t[0].v = triProjected.t[0].v / triProjected.p[0].w;
|
|
triProjected.t[1].v = triProjected.t[1].v / triProjected.p[1].w;
|
|
triProjected.t[2].v = triProjected.t[2].v / triProjected.p[2].w;
|
|
|
|
triProjected.t[0].w = 1.0f / triProjected.p[0].w;
|
|
triProjected.t[1].w = 1.0f / triProjected.p[1].w;
|
|
triProjected.t[2].w = 1.0f / triProjected.p[2].w;
|
|
|
|
|
|
// Scale into view, we moved the normalising into cartesian space
|
|
// out of the matrix.vector function from the previous videos, so
|
|
// do this manually
|
|
triProjected.p[0] = Vector_Div(triProjected.p[0], triProjected.p[0].w);
|
|
triProjected.p[1] = Vector_Div(triProjected.p[1], triProjected.p[1].w);
|
|
triProjected.p[2] = Vector_Div(triProjected.p[2], triProjected.p[2].w);
|
|
|
|
// X/Y are inverted so put them back
|
|
triProjected.p[0].x *= -1.0f;
|
|
triProjected.p[1].x *= -1.0f;
|
|
triProjected.p[2].x *= -1.0f;
|
|
triProjected.p[0].y *= -1.0f;
|
|
triProjected.p[1].y *= -1.0f;
|
|
triProjected.p[2].y *= -1.0f;
|
|
|
|
// Offset verts into visible normalised space
|
|
vec3d vOffsetView = { 1,1,0 };
|
|
triProjected.p[0] = Vector_Add(triProjected.p[0], vOffsetView);
|
|
triProjected.p[1] = Vector_Add(triProjected.p[1], vOffsetView);
|
|
triProjected.p[2] = Vector_Add(triProjected.p[2], vOffsetView);
|
|
triProjected.p[0].x *= 0.5f * (float)ScreenWidth();
|
|
triProjected.p[0].y *= 0.5f * (float)ScreenHeight();
|
|
triProjected.p[1].x *= 0.5f * (float)ScreenWidth();
|
|
triProjected.p[1].y *= 0.5f * (float)ScreenHeight();
|
|
triProjected.p[2].x *= 0.5f * (float)ScreenWidth();
|
|
triProjected.p[2].y *= 0.5f * (float)ScreenHeight();
|
|
|
|
// Store triangle for sorting
|
|
vecTrianglesToRaster.push_back(triProjected);
|
|
}
|
|
}
|
|
}
|
|
|
|
// Sort triangles from back to front
|
|
/*sort(vecTrianglesToRaster.begin(), vecTrianglesToRaster.end(), [](triangle &t1, triangle &t2)
|
|
{
|
|
float z1 = (t1.p[0].z + t1.p[1].z + t1.p[2].z) / 3.0f;
|
|
float z2 = (t2.p[0].z + t2.p[1].z + t2.p[2].z) / 3.0f;
|
|
return z1 > z2;
|
|
});*/
|
|
|
|
// Clear Screen
|
|
Clear(olc::BLACK);
|
|
|
|
// Clear Depth Buffer
|
|
for (int i = 0; i < ScreenWidth()*ScreenHeight(); i++)
|
|
pDepthBuffer[i] = 0.0f;
|
|
|
|
|
|
// Loop through all transformed, viewed, projected, and sorted triangles
|
|
for (auto &triToRaster : vecTrianglesToRaster)
|
|
{
|
|
// Clip triangles against all four screen edges, this could yield
|
|
// a bunch of triangles, so create a queue that we traverse to
|
|
// ensure we only test new triangles generated against planes
|
|
triangle clipped[2];
|
|
list<triangle> listTriangles;
|
|
|
|
// Add initial triangle
|
|
listTriangles.push_back(triToRaster);
|
|
int nNewTriangles = 1;
|
|
|
|
for (int p = 0; p < 4; p++)
|
|
{
|
|
int nTrisToAdd = 0;
|
|
while (nNewTriangles > 0)
|
|
{
|
|
// Take triangle from front of queue
|
|
triangle test = listTriangles.front();
|
|
listTriangles.pop_front();
|
|
nNewTriangles--;
|
|
|
|
// Clip it against a plane. We only need to test each
|
|
// subsequent plane, against subsequent new triangles
|
|
// as all triangles after a plane clip are guaranteed
|
|
// to lie on the inside of the plane. I like how this
|
|
// comment is almost completely and utterly justified
|
|
switch (p)
|
|
{
|
|
case 0: nTrisToAdd = Triangle_ClipAgainstPlane({ 0.0f, 0.0f, 0.0f }, { 0.0f, 1.0f, 0.0f }, test, clipped[0], clipped[1]); break;
|
|
case 1: nTrisToAdd = Triangle_ClipAgainstPlane({ 0.0f, (float)ScreenHeight() - 1, 0.0f }, { 0.0f, -1.0f, 0.0f }, test, clipped[0], clipped[1]); break;
|
|
case 2: nTrisToAdd = Triangle_ClipAgainstPlane({ 0.0f, 0.0f, 0.0f }, { 1.0f, 0.0f, 0.0f }, test, clipped[0], clipped[1]); break;
|
|
case 3: nTrisToAdd = Triangle_ClipAgainstPlane({ (float)ScreenWidth() - 1, 0.0f, 0.0f }, { -1.0f, 0.0f, 0.0f }, test, clipped[0], clipped[1]); break;
|
|
}
|
|
|
|
// Clipping may yield a variable number of triangles, so
|
|
// add these new ones to the back of the queue for subsequent
|
|
// clipping against next planes
|
|
for (int w = 0; w < nTrisToAdd; w++)
|
|
listTriangles.push_back(clipped[w]);
|
|
}
|
|
nNewTriangles = listTriangles.size();
|
|
}
|
|
|
|
|
|
// Draw the transformed, viewed, clipped, projected, sorted, clipped triangles
|
|
for (auto &t : listTriangles)
|
|
{
|
|
#ifdef DO_TEXTURE_DEMO
|
|
TexturedTriangle(t.p[0].x, t.p[0].y, t.t[0].u, t.t[0].v, t.t[0].w,
|
|
t.p[1].x, t.p[1].y, t.t[1].u, t.t[1].v, t.t[1].w,
|
|
t.p[2].x, t.p[2].y, t.t[2].u, t.t[2].v, t.t[2].w, sprTex1);
|
|
#else
|
|
FillTriangle(t.p[0].x, t.p[0].y, t.p[1].x, t.p[1].y, t.p[2].x, t.p[2].y, t.col);
|
|
#endif
|
|
//DrawTriangle(t.p[0].x, t.p[0].y, t.p[1].x, t.p[1].y, t.p[2].x, t.p[2].y, olc::WHITE);
|
|
}
|
|
}
|
|
|
|
|
|
return true;
|
|
}
|
|
|
|
void TexturedTriangle( int x1, int y1, float u1, float v1, float w1,
|
|
int x2, int y2, float u2, float v2, float w2,
|
|
int x3, int y3, float u3, float v3, float w3,
|
|
olc::Sprite *tex)
|
|
{
|
|
if (y2 < y1)
|
|
{
|
|
swap(y1, y2);
|
|
swap(x1, x2);
|
|
swap(u1, u2);
|
|
swap(v1, v2);
|
|
swap(w1, w2);
|
|
}
|
|
|
|
if (y3 < y1)
|
|
{
|
|
swap(y1, y3);
|
|
swap(x1, x3);
|
|
swap(u1, u3);
|
|
swap(v1, v3);
|
|
swap(w1, w3);
|
|
}
|
|
|
|
if (y3 < y2)
|
|
{
|
|
swap(y2, y3);
|
|
swap(x2, x3);
|
|
swap(u2, u3);
|
|
swap(v2, v3);
|
|
swap(w2, w3);
|
|
}
|
|
|
|
int dy1 = y2 - y1;
|
|
int dx1 = x2 - x1;
|
|
float dv1 = v2 - v1;
|
|
float du1 = u2 - u1;
|
|
float dw1 = w2 - w1;
|
|
|
|
int dy2 = y3 - y1;
|
|
int dx2 = x3 - x1;
|
|
float dv2 = v3 - v1;
|
|
float du2 = u3 - u1;
|
|
float dw2 = w3 - w1;
|
|
|
|
float tex_u, tex_v, tex_w;
|
|
|
|
float dax_step = 0, dbx_step = 0,
|
|
du1_step = 0, dv1_step = 0,
|
|
du2_step = 0, dv2_step = 0,
|
|
dw1_step=0, dw2_step=0;
|
|
|
|
if (dy1) dax_step = dx1 / (float)abs(dy1);
|
|
if (dy2) dbx_step = dx2 / (float)abs(dy2);
|
|
|
|
if (dy1) du1_step = du1 / (float)abs(dy1);
|
|
if (dy1) dv1_step = dv1 / (float)abs(dy1);
|
|
if (dy1) dw1_step = dw1 / (float)abs(dy1);
|
|
|
|
if (dy2) du2_step = du2 / (float)abs(dy2);
|
|
if (dy2) dv2_step = dv2 / (float)abs(dy2);
|
|
if (dy2) dw2_step = dw2 / (float)abs(dy2);
|
|
|
|
if (dy1)
|
|
{
|
|
for (int i = y1; i <= y2; i++)
|
|
{
|
|
int ax = x1 + (float)(i - y1) * dax_step;
|
|
int bx = x1 + (float)(i - y1) * dbx_step;
|
|
|
|
float tex_su = u1 + (float)(i - y1) * du1_step;
|
|
float tex_sv = v1 + (float)(i - y1) * dv1_step;
|
|
float tex_sw = w1 + (float)(i - y1) * dw1_step;
|
|
|
|
float tex_eu = u1 + (float)(i - y1) * du2_step;
|
|
float tex_ev = v1 + (float)(i - y1) * dv2_step;
|
|
float tex_ew = w1 + (float)(i - y1) * dw2_step;
|
|
|
|
if (ax > bx)
|
|
{
|
|
swap(ax, bx);
|
|
swap(tex_su, tex_eu);
|
|
swap(tex_sv, tex_ev);
|
|
swap(tex_sw, tex_ew);
|
|
}
|
|
|
|
tex_u = tex_su;
|
|
tex_v = tex_sv;
|
|
tex_w = tex_sw;
|
|
|
|
float tstep = 1.0f / ((float)(bx - ax));
|
|
float t = 0.0f;
|
|
|
|
for (int j = ax; j < bx; j++)
|
|
{
|
|
tex_u = (1.0f - t) * tex_su + t * tex_eu;
|
|
tex_v = (1.0f - t) * tex_sv + t * tex_ev;
|
|
tex_w = (1.0f - t) * tex_sw + t * tex_ew;
|
|
if (tex_w > pDepthBuffer[i*ScreenWidth() + j])
|
|
{
|
|
Draw(j, i, tex->Sample(tex_u / tex_w, tex_v / tex_w));
|
|
pDepthBuffer[i*ScreenWidth() + j] = tex_w;
|
|
}
|
|
t += tstep;
|
|
}
|
|
|
|
}
|
|
}
|
|
|
|
dy1 = y3 - y2;
|
|
dx1 = x3 - x2;
|
|
dv1 = v3 - v2;
|
|
du1 = u3 - u2;
|
|
dw1 = w3 - w2;
|
|
|
|
if (dy1) dax_step = dx1 / (float)abs(dy1);
|
|
if (dy2) dbx_step = dx2 / (float)abs(dy2);
|
|
|
|
du1_step = 0, dv1_step = 0;
|
|
if (dy1) du1_step = du1 / (float)abs(dy1);
|
|
if (dy1) dv1_step = dv1 / (float)abs(dy1);
|
|
if (dy1) dw1_step = dw1 / (float)abs(dy1);
|
|
|
|
if (dy1)
|
|
{
|
|
for (int i = y2; i <= y3; i++)
|
|
{
|
|
int ax = x2 + (float)(i - y2) * dax_step;
|
|
int bx = x1 + (float)(i - y1) * dbx_step;
|
|
|
|
float tex_su = u2 + (float)(i - y2) * du1_step;
|
|
float tex_sv = v2 + (float)(i - y2) * dv1_step;
|
|
float tex_sw = w2 + (float)(i - y2) * dw1_step;
|
|
|
|
float tex_eu = u1 + (float)(i - y1) * du2_step;
|
|
float tex_ev = v1 + (float)(i - y1) * dv2_step;
|
|
float tex_ew = w1 + (float)(i - y1) * dw2_step;
|
|
|
|
if (ax > bx)
|
|
{
|
|
swap(ax, bx);
|
|
swap(tex_su, tex_eu);
|
|
swap(tex_sv, tex_ev);
|
|
swap(tex_sw, tex_ew);
|
|
}
|
|
|
|
tex_u = tex_su;
|
|
tex_v = tex_sv;
|
|
tex_w = tex_sw;
|
|
|
|
float tstep = 1.0f / ((float)(bx - ax));
|
|
float t = 0.0f;
|
|
|
|
for (int j = ax; j < bx; j++)
|
|
{
|
|
tex_u = (1.0f - t) * tex_su + t * tex_eu;
|
|
tex_v = (1.0f - t) * tex_sv + t * tex_ev;
|
|
tex_w = (1.0f - t) * tex_sw + t * tex_ew;
|
|
|
|
if (tex_w > pDepthBuffer[i*ScreenWidth() + j])
|
|
{
|
|
Draw(j, i, tex->Sample(tex_u / tex_w, tex_v / tex_w));
|
|
pDepthBuffer[i*ScreenWidth() + j] = tex_w;
|
|
}
|
|
t += tstep;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
int main()
|
|
{
|
|
olcEngine3D demo;
|
|
if (demo.Construct(512, 480, 2, 2))
|
|
demo.Start();
|
|
return 0;
|
|
}
|
|
|
|
|