From 774dbabd301a52cde03105040bfe2bf985d89628 Mon Sep 17 00:00:00 2001 From: Javidx9 <25419386+OneLoneCoder@users.noreply.github.com> Date: Sat, 19 Jan 2019 22:55:56 +0000 Subject: [PATCH] Initial version of PGEX_Graphics3D --- olcPGEX_Graphics3D.h | 1173 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1173 insertions(+) create mode 100644 olcPGEX_Graphics3D.h diff --git a/olcPGEX_Graphics3D.h b/olcPGEX_Graphics3D.h new file mode 100644 index 0000000..d3e217a --- /dev/null +++ b/olcPGEX_Graphics3D.h @@ -0,0 +1,1173 @@ +/* + olcPGEX_Graphics3D.h + + +-------------------------------------------------------------+ + | OneLoneCoder Pixel Game Engine Extension | + | 3D Rendering - v0.1 | + +-------------------------------------------------------------+ + + What is this? + ~~~~~~~~~~~~~ + This is an extension to the olcPixelGameEngine, which provides + support for software rendering 3D graphics. + + NOTE!!! This file is under development and may change! + + License (OLC-3) + ~~~~~~~~~~~~~~~ + + Copyright 2018-2019 OneLoneCoder.com + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions + are met: + + 1. Redistributions or derivations of source code must retain the above + copyright notice, this list of conditions and the following disclaimer. + + 2. Redistributions or derivative works in binary form must reproduce + the above copyright notice. This list of conditions and the following + disclaimer must be reproduced in the documentation and/or other + materials provided with the distribution. + + 3. Neither the name of the copyright holder nor the names of its + contributors may be used to endorse or promote products derived + from this software without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + + Links + ~~~~~ + YouTube: https://www.youtube.com/javidx9 + Discord: https://discord.gg/WhwHUMV + Twitter: https://www.twitter.com/javidx9 + Twitch: https://www.twitch.tv/javidx9 + GitHub: https://www.github.com/onelonecoder + Homepage: https://www.onelonecoder.com + + Author + ~~~~~~ + David Barr, aka javidx9, ŠOneLoneCoder 2018 +*/ + + +#ifndef OLC_PGEX_GFX3D +#define OLC_PGEX_GFX3D + +#include +#include +#include +#undef min +#undef max + +namespace olc +{ + // Container class for Advanced 2D Drawing functions + class GFX3D : public olc::PGEX + { + + public: + + struct vec2d + { + float x = 0; + float y = 0; + float z = 0; + }; + + struct vec3d + { + float x = 0; + float y = 0; + float z = 0; + float w = 1; // Need a 4th term to perform sensible matrix vector multiplication + }; + + struct triangle + { + vec3d p[3]; + vec2d t[3]; + olc::Pixel col; + }; + + struct mat4x4 + { + float m[4][4] = { 0 }; + }; + + struct mesh + { + std::vector tris; + }; + + class Math + { + public: + inline Math(); + public: + inline static vec3d Mat_MultiplyVector(mat4x4 &m, vec3d &i); + inline static mat4x4 Mat_MultiplyMatrix(mat4x4 &m1, mat4x4 &m2); + inline static mat4x4 Mat_MakeIdentity(); + inline static mat4x4 Mat_MakeRotationX(float fAngleRad); + inline static mat4x4 Mat_MakeRotationY(float fAngleRad); + inline static mat4x4 Mat_MakeRotationZ(float fAngleRad); + inline static mat4x4 Mat_MakeScale(float x, float y, float z); + inline static mat4x4 Mat_MakeTranslation(float x, float y, float z); + inline static mat4x4 Mat_MakeProjection(float fFovDegrees, float fAspectRatio, float fNear, float fFar); + inline static mat4x4 Mat_PointAt(vec3d &pos, vec3d &target, vec3d &up); + inline static mat4x4 Mat_QuickInverse(mat4x4 &m); // Only for Rotation/Translation Matrices + inline static mat4x4 Mat_Inverse(olc::GFX3D::mat4x4 &m); + + inline static vec3d Vec_Add(vec3d &v1, vec3d &v2); + inline static vec3d Vec_Sub(vec3d &v1, vec3d &v2); + inline static vec3d Vec_Mul(vec3d &v1, float k); + inline static vec3d Vec_Div(vec3d &v1, float k); + inline static float Vec_DotProduct(vec3d &v1, vec3d &v2); + inline static float Vec_Length(vec3d &v); + inline static vec3d Vec_Normalise(vec3d &v); + inline static vec3d Vec_CrossProduct(vec3d &v1, vec3d &v2); + inline static vec3d Vec_IntersectPlane(vec3d &plane_p, vec3d &plane_n, vec3d &lineStart, vec3d &lineEnd, float &t); + + inline static int Triangle_ClipAgainstPlane(vec3d plane_p, vec3d plane_n, triangle &in_tri, triangle &out_tri1, triangle &out_tri2); + }; + + enum RENDERFLAGS + { + RENDER_WIRE = 0x01, + RENDER_FLAT = 0x02, + RENDER_TEXTURED = 0x04, + RENDER_CULL_CW = 0x08, + RENDER_CULL_CCW = 0x10, + RENDER_DEPTH = 0x20, + }; + + + class PipeLine + { + public: + PipeLine(); + + public: + void SetProjection(float fFovDegrees, float fAspectRatio, float fNear, float fFar, float fLeft, float fTop, float fWidth, float fHeight); + void SetCamera(olc::GFX3D::vec3d &pos, olc::GFX3D::vec3d &lookat, olc::GFX3D::vec3d &up); + void SetTransform(olc::GFX3D::mat4x4 &transform); + void SetTexture(olc::Sprite *texture); + void SetLightSource(olc::GFX3D::vec3d &pos, olc::GFX3D::vec3d &dir, olc::Pixel &col); + uint32_t Render(std::vector &triangles, uint32_t flags = RENDER_CULL_CW | RENDER_TEXTURED | RENDER_DEPTH); + + private: + olc::GFX3D::mat4x4 matProj; + olc::GFX3D::mat4x4 matView; + olc::GFX3D::mat4x4 matWorld; + olc::Sprite *sprTexture; + float fViewX; + float fViewY; + float fViewW; + float fViewH; + }; + + + + public: + //static const int RF_TEXTURE = 0x00000001; + //static const int RF_ = 0x00000002; + + inline static void ConfigureDisplay(); + inline static void ClearDepth(); + inline static void AddTriangleToScene(olc::GFX3D::triangle &tri); + inline static void RenderScene(); + + inline static void DrawTriangleFlat(olc::GFX3D::triangle &tri); + inline static void DrawTriangleWire(olc::GFX3D::triangle &tri, olc::Pixel col = olc::WHITE); + inline static void DrawTriangleTex(olc::GFX3D::triangle &tri, olc::Sprite* spr); + inline static 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* spr); + + // Draws a sprite with the transform applied + //inline static void DrawSprite(olc::Sprite *sprite, olc::GFX2D::Transform2D &transform); + + private: + static float* m_DepthBuffer; + }; +} + + + + +namespace olc +{ + olc::GFX3D::Math::Math() + { + + } + + olc::GFX3D::vec3d olc::GFX3D::Math::Mat_MultiplyVector(olc::GFX3D::mat4x4 &m, olc::GFX3D::vec3d &i) + { + vec3d v; + 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]; + 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]; + 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]; + 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]; + return v; + } + + olc::GFX3D::mat4x4 olc::GFX3D::Math::Mat_MakeIdentity() + { + olc::GFX3D::mat4x4 matrix; + matrix.m[0][0] = 1.0f; + matrix.m[1][1] = 1.0f; + matrix.m[2][2] = 1.0f; + matrix.m[3][3] = 1.0f; + return matrix; + } + + olc::GFX3D::mat4x4 olc::GFX3D::Math::Mat_MakeRotationX(float fAngleRad) + { + olc::GFX3D::mat4x4 matrix; + matrix.m[0][0] = 1.0f; + matrix.m[1][1] = cosf(fAngleRad); + matrix.m[1][2] = sinf(fAngleRad); + matrix.m[2][1] = -sinf(fAngleRad); + matrix.m[2][2] = cosf(fAngleRad); + matrix.m[3][3] = 1.0f; + return matrix; + } + + olc::GFX3D::mat4x4 olc::GFX3D::Math::Mat_MakeRotationY(float fAngleRad) + { + olc::GFX3D::mat4x4 matrix; + matrix.m[0][0] = cosf(fAngleRad); + matrix.m[0][2] = sinf(fAngleRad); + matrix.m[2][0] = -sinf(fAngleRad); + matrix.m[1][1] = 1.0f; + matrix.m[2][2] = cosf(fAngleRad); + matrix.m[3][3] = 1.0f; + return matrix; + } + + olc::GFX3D::mat4x4 olc::GFX3D::Math::Mat_MakeRotationZ(float fAngleRad) + { + olc::GFX3D::mat4x4 matrix; + matrix.m[0][0] = cosf(fAngleRad); + matrix.m[0][1] = sinf(fAngleRad); + matrix.m[1][0] = -sinf(fAngleRad); + matrix.m[1][1] = cosf(fAngleRad); + matrix.m[2][2] = 1.0f; + matrix.m[3][3] = 1.0f; + return matrix; + } + + olc::GFX3D::mat4x4 olc::GFX3D::Math::Mat_MakeScale(float x, float y, float z) + { + olc::GFX3D::mat4x4 matrix; + matrix.m[0][0] = x; + matrix.m[1][1] = y; + matrix.m[2][2] = z; + matrix.m[3][3] = 1.0f; + return matrix; + } + + olc::GFX3D::mat4x4 olc::GFX3D::Math::Mat_MakeTranslation(float x, float y, float z) + { + olc::GFX3D::mat4x4 matrix; + matrix.m[0][0] = 1.0f; + matrix.m[1][1] = 1.0f; + matrix.m[2][2] = 1.0f; + matrix.m[3][3] = 1.0f; + matrix.m[3][0] = x; + matrix.m[3][1] = y; + matrix.m[3][2] = z; + return matrix; + } + + olc::GFX3D::mat4x4 olc::GFX3D::Math::Mat_MakeProjection(float fFovDegrees, float fAspectRatio, float fNear, float fFar) + { + float fFovRad = 1.0f / tanf(fFovDegrees * 0.5f / 180.0f * 3.14159f); + olc::GFX3D::mat4x4 matrix; + matrix.m[0][0] = fAspectRatio * fFovRad; + matrix.m[1][1] = fFovRad; + matrix.m[2][2] = fFar / (fFar - fNear); + matrix.m[3][2] = (-fFar * fNear) / (fFar - fNear); + matrix.m[2][3] = 1.0f; + matrix.m[3][3] = 0.0f; + return matrix; + } + + olc::GFX3D::mat4x4 olc::GFX3D::Math::Mat_MultiplyMatrix(olc::GFX3D::mat4x4 &m1, olc::GFX3D::mat4x4 &m2) + { + olc::GFX3D::mat4x4 matrix; + for (int c = 0; c < 4; c++) + for (int r = 0; r < 4; r++) + 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]; + return matrix; + } + + olc::GFX3D::mat4x4 olc::GFX3D::Math::Mat_PointAt(olc::GFX3D::vec3d &pos, olc::GFX3D::vec3d &target, olc::GFX3D::vec3d &up) + { + // Calculate new forward direction + olc::GFX3D::vec3d newForward = Vec_Sub(target, pos); + newForward = Vec_Normalise(newForward); + + // Calculate new Up direction + olc::GFX3D::vec3d a = Vec_Mul(newForward, Vec_DotProduct(up, newForward)); + olc::GFX3D::vec3d newUp = Vec_Sub(up, a); + newUp = Vec_Normalise(newUp); + + // New Right direction is easy, its just cross product + olc::GFX3D::vec3d newRight = Vec_CrossProduct(newUp, newForward); + + // Construct Dimensioning and Translation Matrix + olc::GFX3D::mat4x4 matrix; + matrix.m[0][0] = newRight.x; matrix.m[0][1] = newRight.y; matrix.m[0][2] = newRight.z; matrix.m[0][3] = 0.0f; + matrix.m[1][0] = newUp.x; matrix.m[1][1] = newUp.y; matrix.m[1][2] = newUp.z; matrix.m[1][3] = 0.0f; + matrix.m[2][0] = newForward.x; matrix.m[2][1] = newForward.y; matrix.m[2][2] = newForward.z; matrix.m[2][3] = 0.0f; + matrix.m[3][0] = pos.x; matrix.m[3][1] = pos.y; matrix.m[3][2] = pos.z; matrix.m[3][3] = 1.0f; + return matrix; + + } + + olc::GFX3D::mat4x4 olc::GFX3D::Math::Mat_QuickInverse(olc::GFX3D::mat4x4 &m) // Only for Rotation/Translation Matrices + { + olc::GFX3D::mat4x4 matrix; + 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; + 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; + 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; + 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]); + 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]); + 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]); + matrix.m[3][3] = 1.0f; + return matrix; + } + + olc::GFX3D::mat4x4 olc::GFX3D::Math::Mat_Inverse(olc::GFX3D::mat4x4 &m) + { + double det; + + + mat4x4 matInv; + + matInv.m[0][0] = m.m[1][1] * m.m[2][2] * m.m[3][3] - m.m[1][1] * m.m[2][3] * m.m[3][2] - m.m[2][1] * m.m[1][2] * m.m[3][3] + m.m[2][1] * m.m[1][3] * m.m[3][2] + m.m[3][1] * m.m[1][2] * m.m[2][3] - m.m[3][1] * m.m[1][3] * m.m[2][2]; + matInv.m[1][0] = -m.m[1][0] * m.m[2][2] * m.m[3][3] + m.m[1][0] * m.m[2][3] * m.m[3][2] + m.m[2][0] * m.m[1][2] * m.m[3][3] - m.m[2][0] * m.m[1][3] * m.m[3][2] - m.m[3][0] * m.m[1][2] * m.m[2][3] + m.m[3][0] * m.m[1][3] * m.m[2][2]; + matInv.m[2][0] = m.m[1][0] * m.m[2][1] * m.m[3][3] - m.m[1][0] * m.m[2][3] * m.m[3][1] - m.m[2][0] * m.m[1][1] * m.m[3][3] + m.m[2][0] * m.m[1][3] * m.m[3][1] + m.m[3][0] * m.m[1][1] * m.m[2][3] - m.m[3][0] * m.m[1][3] * m.m[2][1]; + matInv.m[3][0] = -m.m[1][0] * m.m[2][1] * m.m[3][2] + m.m[1][0] * m.m[2][2] * m.m[3][1] + m.m[2][0] * m.m[1][1] * m.m[3][2] - m.m[2][0] * m.m[1][2] * m.m[3][1] - m.m[3][0] * m.m[1][1] * m.m[2][2] + m.m[3][0] * m.m[1][2] * m.m[2][1]; + matInv.m[0][1] = -m.m[0][1] * m.m[2][2] * m.m[3][3] + m.m[0][1] * m.m[2][3] * m.m[3][2] + m.m[2][1] * m.m[0][2] * m.m[3][3] - m.m[2][1] * m.m[0][3] * m.m[3][2] - m.m[3][1] * m.m[0][2] * m.m[2][3] + m.m[3][1] * m.m[0][3] * m.m[2][2]; + matInv.m[1][1] = m.m[0][0] * m.m[2][2] * m.m[3][3] - m.m[0][0] * m.m[2][3] * m.m[3][2] - m.m[2][0] * m.m[0][2] * m.m[3][3] + m.m[2][0] * m.m[0][3] * m.m[3][2] + m.m[3][0] * m.m[0][2] * m.m[2][3] - m.m[3][0] * m.m[0][3] * m.m[2][2]; + matInv.m[2][1] = -m.m[0][0] * m.m[2][1] * m.m[3][3] + m.m[0][0] * m.m[2][3] * m.m[3][1] + m.m[2][0] * m.m[0][1] * m.m[3][3] - m.m[2][0] * m.m[0][3] * m.m[3][1] - m.m[3][0] * m.m[0][1] * m.m[2][3] + m.m[3][0] * m.m[0][3] * m.m[2][1]; + matInv.m[3][1] = m.m[0][0] * m.m[2][1] * m.m[3][2] - m.m[0][0] * m.m[2][2] * m.m[3][1] - m.m[2][0] * m.m[0][1] * m.m[3][2] + m.m[2][0] * m.m[0][2] * m.m[3][1] + m.m[3][0] * m.m[0][1] * m.m[2][2] - m.m[3][0] * m.m[0][2] * m.m[2][1]; + matInv.m[0][2] = m.m[0][1] * m.m[1][2] * m.m[3][3] - m.m[0][1] * m.m[1][3] * m.m[3][2] - m.m[1][1] * m.m[0][2] * m.m[3][3] + m.m[1][1] * m.m[0][3] * m.m[3][2] + m.m[3][1] * m.m[0][2] * m.m[1][3] - m.m[3][1] * m.m[0][3] * m.m[1][2]; + matInv.m[1][2] = -m.m[0][0] * m.m[1][2] * m.m[3][3] + m.m[0][0] * m.m[1][3] * m.m[3][2] + m.m[1][0] * m.m[0][2] * m.m[3][3] - m.m[1][0] * m.m[0][3] * m.m[3][2] - m.m[3][0] * m.m[0][2] * m.m[1][3] + m.m[3][0] * m.m[0][3] * m.m[1][2]; + matInv.m[2][2] = m.m[0][0] * m.m[1][1] * m.m[3][3] - m.m[0][0] * m.m[1][3] * m.m[3][1] - m.m[1][0] * m.m[0][1] * m.m[3][3] + m.m[1][0] * m.m[0][3] * m.m[3][1] + m.m[3][0] * m.m[0][1] * m.m[1][3] - m.m[3][0] * m.m[0][3] * m.m[1][1]; + matInv.m[3][2] = -m.m[0][0] * m.m[1][1] * m.m[3][2] + m.m[0][0] * m.m[1][2] * m.m[3][1] + m.m[1][0] * m.m[0][1] * m.m[3][2] - m.m[1][0] * m.m[0][2] * m.m[3][1] - m.m[3][0] * m.m[0][1] * m.m[1][2] + m.m[3][0] * m.m[0][2] * m.m[1][1]; + matInv.m[0][3] = -m.m[0][1] * m.m[1][2] * m.m[2][3] + m.m[0][1] * m.m[1][3] * m.m[2][2] + m.m[1][1] * m.m[0][2] * m.m[2][3] - m.m[1][1] * m.m[0][3] * m.m[2][2] - m.m[2][1] * m.m[0][2] * m.m[1][3] + m.m[2][1] * m.m[0][3] * m.m[1][2]; + matInv.m[1][3] = m.m[0][0] * m.m[1][2] * m.m[2][3] - m.m[0][0] * m.m[1][3] * m.m[2][2] - m.m[1][0] * m.m[0][2] * m.m[2][3] + m.m[1][0] * m.m[0][3] * m.m[2][2] + m.m[2][0] * m.m[0][2] * m.m[1][3] - m.m[2][0] * m.m[0][3] * m.m[1][2]; + matInv.m[2][3] = -m.m[0][0] * m.m[1][1] * m.m[2][3] + m.m[0][0] * m.m[1][3] * m.m[2][1] + m.m[1][0] * m.m[0][1] * m.m[2][3] - m.m[1][0] * m.m[0][3] * m.m[2][1] - m.m[2][0] * m.m[0][1] * m.m[1][3] + m.m[2][0] * m.m[0][3] * m.m[1][1]; + matInv.m[3][3] = m.m[0][0] * m.m[1][1] * m.m[2][2] - m.m[0][0] * m.m[1][2] * m.m[2][1] - m.m[1][0] * m.m[0][1] * m.m[2][2] + m.m[1][0] * m.m[0][2] * m.m[2][1] + m.m[2][0] * m.m[0][1] * m.m[1][2] - m.m[2][0] * m.m[0][2] * m.m[1][1]; + + det = m.m[0][0] * matInv.m[0][0] + m.m[0][1] * matInv.m[1][0] + m.m[0][2] * matInv.m[2][0] + m.m[0][3] * matInv.m[3][0]; + // if (det == 0) return false; + + det = 1.0 / det; + + for (int i = 0; i < 4; i++) + for (int j = 0; j < 4; j++) + matInv.m[i][j] *= (float)det; + + return matInv; + } + + olc::GFX3D::vec3d olc::GFX3D::Math::Vec_Add(olc::GFX3D::vec3d &v1, olc::GFX3D::vec3d &v2) + { + return { v1.x + v2.x, v1.y + v2.y, v1.z + v2.z }; + } + + olc::GFX3D::vec3d olc::GFX3D::Math::Vec_Sub(olc::GFX3D::vec3d &v1, olc::GFX3D::vec3d &v2) + { + return { v1.x - v2.x, v1.y - v2.y, v1.z - v2.z }; + } + + olc::GFX3D::vec3d olc::GFX3D::Math::Vec_Mul(olc::GFX3D::vec3d &v1, float k) + { + return { v1.x * k, v1.y * k, v1.z * k }; + } + + olc::GFX3D::vec3d olc::GFX3D::Math::Vec_Div(olc::GFX3D::vec3d &v1, float k) + { + return { v1.x / k, v1.y / k, v1.z / k }; + } + + float olc::GFX3D::Math::Vec_DotProduct(olc::GFX3D::vec3d &v1, olc::GFX3D::vec3d &v2) + { + return v1.x*v2.x + v1.y*v2.y + v1.z * v2.z; + } + + float olc::GFX3D::Math::Vec_Length(olc::GFX3D::vec3d &v) + { + return sqrtf(Vec_DotProduct(v, v)); + } + + olc::GFX3D::vec3d olc::GFX3D::Math::Vec_Normalise(olc::GFX3D::vec3d &v) + { + float l = Vec_Length(v); + return { v.x / l, v.y / l, v.z / l }; + } + + olc::GFX3D::vec3d olc::GFX3D::Math::Vec_CrossProduct(olc::GFX3D::vec3d &v1, olc::GFX3D::vec3d &v2) + { + vec3d v; + v.x = v1.y * v2.z - v1.z * v2.y; + v.y = v1.z * v2.x - v1.x * v2.z; + v.z = v1.x * v2.y - v1.y * v2.x; + return v; + } + + olc::GFX3D::vec3d olc::GFX3D::Math::Vec_IntersectPlane(olc::GFX3D::vec3d &plane_p, olc::GFX3D::vec3d &plane_n, olc::GFX3D::vec3d &lineStart, olc::GFX3D::vec3d &lineEnd, float &t) + { + plane_n = Vec_Normalise(plane_n); + float plane_d = -Vec_DotProduct(plane_n, plane_p); + float ad = Vec_DotProduct(lineStart, plane_n); + float bd = Vec_DotProduct(lineEnd, plane_n); + t = (-plane_d - ad) / (bd - ad); + olc::GFX3D::vec3d lineStartToEnd = Vec_Sub(lineEnd, lineStart); + olc::GFX3D::vec3d lineToIntersect = Vec_Mul(lineStartToEnd, t); + return Vec_Add(lineStart, lineToIntersect); + } + + + int olc::GFX3D::Math::Triangle_ClipAgainstPlane(vec3d plane_p, vec3d plane_n, triangle &in_tri, triangle &out_tri1, triangle &out_tri2) + { + // Make sure plane normal is indeed normal + plane_n = Math::Vec_Normalise(plane_n); + + out_tri1.t[0] = in_tri.t[0]; + out_tri2.t[0] = in_tri.t[0]; + out_tri1.t[1] = in_tri.t[1]; + out_tri2.t[1] = in_tri.t[1]; + out_tri1.t[2] = in_tri.t[2]; + out_tri2.t[2] = in_tri.t[2]; + + // Return signed shortest distance from point to plane, plane normal must be normalised + auto dist = [&](vec3d &p) + { + vec3d n = Math::Vec_Normalise(p); + return (plane_n.x * p.x + plane_n.y * p.y + plane_n.z * p.z - Math::Vec_DotProduct(plane_n, plane_p)); + }; + + // Create two temporary storage arrays to classify points either side of plane + // If distance sign is positive, point lies on "inside" of plane + vec3d* inside_points[3]; int nInsidePointCount = 0; + vec3d* outside_points[3]; int nOutsidePointCount = 0; + vec2d* inside_tex[3]; int nInsideTexCount = 0; + vec2d* outside_tex[3]; int nOutsideTexCount = 0; + + + // Get signed distance of each point in triangle to plane + float d0 = dist(in_tri.p[0]); + float d1 = dist(in_tri.p[1]); + float d2 = dist(in_tri.p[2]); + + if (d0 >= 0) { inside_points[nInsidePointCount++] = &in_tri.p[0]; inside_tex[nInsideTexCount++] = &in_tri.t[0]; } + else { + outside_points[nOutsidePointCount++] = &in_tri.p[0]; outside_tex[nOutsideTexCount++] = &in_tri.t[0]; + } + if (d1 >= 0) { + inside_points[nInsidePointCount++] = &in_tri.p[1]; inside_tex[nInsideTexCount++] = &in_tri.t[1]; + } + else { + outside_points[nOutsidePointCount++] = &in_tri.p[1]; outside_tex[nOutsideTexCount++] = &in_tri.t[1]; + } + if (d2 >= 0) { + inside_points[nInsidePointCount++] = &in_tri.p[2]; inside_tex[nInsideTexCount++] = &in_tri.t[2]; + } + else { + outside_points[nOutsidePointCount++] = &in_tri.p[2]; outside_tex[nOutsideTexCount++] = &in_tri.t[2]; + } + + // Now classify triangle points, and break the input triangle into + // smaller output triangles if required. There are four possible + // outcomes... + + if (nInsidePointCount == 0) + { + // All points lie on the outside of plane, so clip whole triangle + // It ceases to exist + + return 0; // No returned triangles are valid + } + + if (nInsidePointCount == 3) + { + // All points lie on the inside of plane, so do nothing + // and allow the triangle to simply pass through + out_tri1 = in_tri; + + 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 = olc::MAGENTA;// 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] = Math::Vec_IntersectPlane(plane_p, plane_n, *inside_points[0], *outside_points[0], t); + out_tri1.t[1].x = t * (outside_tex[0]->x - inside_tex[0]->x) + inside_tex[0]->x; + out_tri1.t[1].y = t * (outside_tex[0]->y - inside_tex[0]->y) + inside_tex[0]->y; + out_tri1.t[1].z = t * (outside_tex[0]->z - inside_tex[0]->z) + inside_tex[0]->z; + + out_tri1.p[2] = Math::Vec_IntersectPlane(plane_p, plane_n, *inside_points[0], *outside_points[1], t); + out_tri1.t[2].x = t * (outside_tex[1]->x - inside_tex[0]->x) + inside_tex[0]->x; + out_tri1.t[2].y = t * (outside_tex[1]->y - inside_tex[0]->y) + inside_tex[0]->y; + out_tri1.t[2].z = t * (outside_tex[1]->z - inside_tex[0]->z) + inside_tex[0]->z; + + 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 = olc::GREEN;// in_tri.col; + out_tri2.col = olc::RED;// 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.t[0] = *inside_tex[0]; + + out_tri1.p[1] = *inside_points[1]; + out_tri1.t[1] = *inside_tex[1]; + + float t; + out_tri1.p[2] = Math::Vec_IntersectPlane(plane_p, plane_n, *inside_points[0], *outside_points[0], t); + out_tri1.t[2].x = t * (outside_tex[0]->x - inside_tex[0]->x) + inside_tex[0]->x; + out_tri1.t[2].y = t * (outside_tex[0]->y - inside_tex[0]->y) + inside_tex[0]->y; + out_tri1.t[2].z = t * (outside_tex[0]->z - inside_tex[0]->z) + inside_tex[0]->z; + + // 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[1] = *inside_points[1]; + out_tri2.t[1] = *inside_tex[1]; + out_tri2.p[0] = out_tri1.p[2]; + out_tri2.t[0] = out_tri1.t[2]; + out_tri2.p[2] = Math::Vec_IntersectPlane(plane_p, plane_n, *inside_points[1], *outside_points[0], t); + out_tri2.t[2].x = t * (outside_tex[0]->x - inside_tex[1]->x) + inside_tex[1]->x; + out_tri2.t[2].y = t * (outside_tex[0]->y - inside_tex[1]->y) + inside_tex[1]->y; + out_tri2.t[2].z = t * (outside_tex[0]->z - inside_tex[1]->z) + inside_tex[1]->z; + return 2; // Return two newly formed triangles which form a quad + } + + return 0; + } + + void GFX3D::DrawTriangleFlat(olc::GFX3D::triangle &tri) + { + pge->FillTriangle(tri.p[0].x, tri.p[0].y, tri.p[1].x, tri.p[1].y, tri.p[2].x, tri.p[2].y, tri.col); + } + + void GFX3D::DrawTriangleWire(olc::GFX3D::triangle &tri, olc::Pixel col) + { + pge->DrawTriangle(tri.p[0].x, tri.p[0].y, tri.p[1].x, tri.p[1].y, tri.p[2].x, tri.p[2].y, col); + } + + void GFX3D::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* spr) + + { + if (y2 < y1) + { + std::swap(y1, y2); + std::swap(x1, x2); + std::swap(u1, u2); + std::swap(v1, v2); + std::swap(w1, w2); + } + + if (y3 < y1) + { + std::swap(y1, y3); + std::swap(x1, x3); + std::swap(u1, u3); + std::swap(v1, v3); + std::swap(w1, w3); + } + + if (y3 < y2) + { + std::swap(y2, y3); + std::swap(x2, x3); + std::swap(u2, u3); + std::swap(v2, v3); + std::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) + { + std::swap(ax, bx); + std::swap(tex_su, tex_eu); + std::swap(tex_sv, tex_ev); + std::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 > m_DepthBuffer[i*pge->ScreenWidth() + j]) + { + pge->Draw(j, i, spr->Sample(tex_u / tex_w, tex_v / tex_w)); + m_DepthBuffer[i*pge->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) + { + std::swap(ax, bx); + std::swap(tex_su, tex_eu); + std::swap(tex_sv, tex_ev); + std::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 > m_DepthBuffer[i*pge->ScreenWidth() + j]) + { + pge->Draw(j, i, spr->Sample(tex_u / tex_w, tex_v / tex_w)); + m_DepthBuffer[i*pge->ScreenWidth() + j] = tex_w; + } + t += tstep; + } + } + } + } + + + void GFX3D::DrawTriangleTex(olc::GFX3D::triangle &tri, olc::Sprite* spr) + { + if (tri.p[1].y < tri.p[0].y) + { + std::swap(tri.p[0].y, tri.p[1].y); + std::swap(tri.p[0].x, tri.p[1].x); + std::swap(tri.t[0].x, tri.t[1].x); + std::swap(tri.t[0].y, tri.t[1].y); + std::swap(tri.t[0].z, tri.t[1].z); + } + + if (tri.p[2].y < tri.p[0].y) + { + std::swap(tri.p[0].y, tri.p[2].y); + std::swap(tri.p[0].x, tri.p[2].x); + std::swap(tri.t[0].x, tri.t[2].x); + std::swap(tri.t[0].y, tri.t[2].y); + std::swap(tri.t[0].z, tri.t[2].z); + } + + if (tri.p[2].y < tri.p[1].y) + { + std::swap(tri.p[1].y, tri.p[2].y); + std::swap(tri.p[1].x, tri.p[2].x); + std::swap(tri.t[1].x, tri.t[2].x); + std::swap(tri.t[1].y, tri.t[2].y); + std::swap(tri.t[1].z, tri.t[2].z); + } + + int dy1 = tri.p[1].y - tri.p[0].y; + int dx1 = tri.p[1].x - tri.p[0].x; + float dv1 = tri.t[1].y - tri.t[0].y; + float du1 = tri.t[1].x - tri.t[0].x; + float dz1 = tri.t[1].z - tri.t[0].z; + + int dy2 = tri.p[2].y - tri.p[0].y; + int dx2 = tri.p[2].x - tri.p[0].x; + float dv2 = tri.t[2].y - tri.t[0].y; + float du2 = tri.t[2].x - tri.t[0].x; + float dz2 = tri.t[2].z - tri.t[0].z; + + float tex_x, tex_y, tex_z; + + float du1_step = 0, dv1_step = 0, du2_step = 0, dv2_step = 0, dz1_step = 0, dz2_step = 0; + float dax_step = 0, dbx_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) dz1_step = dz1 / (float)abs(dy1); + + if (dy2) du2_step = du2 / (float)abs(dy2); + if (dy2) dv2_step = dv2 / (float)abs(dy2); + if (dy2) dz2_step = dz2 / (float)abs(dy2); + + + + if (dy1) + { + for (int i = tri.p[0].y; i <= tri.p[1].y; i++) + { + int ax = tri.p[0].x + (i - tri.p[0].y) * dax_step; + int bx = tri.p[0].x + (i - tri.p[0].y) * dbx_step; + + // Start and end points in texture space + float tex_su = tri.t[0].x + (float)(i - tri.p[0].y) * du1_step; + float tex_sv = tri.t[0].y + (float)(i - tri.p[0].y) * dv1_step; + float tex_sz = tri.t[0].z + (float)(i - tri.p[0].y) * dz1_step; + + float tex_eu = tri.t[0].x + (float)(i - tri.p[0].y) * du2_step; + float tex_ev = tri.t[0].y + (float)(i - tri.p[0].y) * dv2_step; + float tex_ez = tri.t[0].z + (float)(i - tri.p[0].y) * dz2_step; + + if (ax > bx) + { + std::swap(ax, bx); + std::swap(tex_su, tex_eu); + std::swap(tex_sv, tex_ev); + std::swap(tex_sz, tex_ez); + } + + tex_x = tex_su; + tex_y = tex_sv; + tex_z = tex_sz; + + + float tstep = 1.0f / ((float)(bx - ax)); + float t = 0; + + for (int j = ax; j < bx; j++) + { + tex_x = (1.0f - t) * tex_su + t * tex_eu; + tex_y = (1.0f - t) * tex_sv + t * tex_ev; + tex_z = (1.0f - t) * tex_sz + t * tex_ez; + + if (tex_z > m_DepthBuffer[i*pge->ScreenWidth() + j]) + { + pge->Draw(j, i, spr->Sample(tex_x / tex_z, tex_y / tex_z)); + m_DepthBuffer[i*pge->ScreenWidth() + j] = tex_z; + } + t += tstep; + } + + + } + } + + dy1 = tri.p[2].y - tri.p[1].y; + dx1 = tri.p[2].x - tri.p[1].x; + dv1 = tri.t[2].y - tri.t[1].y; + du1 = tri.t[2].x - tri.t[1].x; + dz1 = tri.t[2].z - tri.t[1].z; + + if (dy1) dax_step = dx1 / (float)abs(dy1); + if (dy2) dbx_step = dx2 / (float)abs(dy2); + + + du1_step = 0, dv1_step = 0;// , dz1_step = 0;// , du2_step = 0, dv2_step = 0; + if (dy1) du1_step = du1 / (float)abs(dy1); + if (dy1) dv1_step = dv1 / (float)abs(dy1); + if (dy1) dz1_step = dz1 / (float)abs(dy1); + + if (dy1) + { + for (int i = tri.p[1].y; i <= tri.p[2].y; i++) + { + int ax = tri.p[1].x + (i - tri.p[1].y) * dax_step; + int bx = tri.p[0].x + (i - tri.p[0].y) * dbx_step; + + // Start and end points in texture space + float tex_su = tri.t[1].x + (float)(i - tri.p[1].y) * du1_step; + float tex_sv = tri.t[1].y + (float)(i - tri.p[1].y) * dv1_step; + float tex_sz = tri.t[1].z + (float)(i - tri.p[1].y) * dz1_step; + + float tex_eu = tri.t[0].x + (float)(i - tri.p[0].y) * du2_step; + float tex_ev = tri.t[0].y + (float)(i - tri.p[0].y) * dv2_step; + float tex_ez = tri.t[0].z + (float)(i - tri.p[0].y) * dz2_step; + + if (ax > bx) + { + std::swap(ax, bx); + std::swap(tex_su, tex_eu); + std::swap(tex_sv, tex_ev); + std::swap(tex_sz, tex_ez); + } + + tex_x = tex_su; + tex_y = tex_sv; + tex_z = tex_sz; + + + float tstep = 1.0f / ((float)(bx - ax)); + float t = 0; + + for (int j = ax; j < bx; j++) + { + tex_x = (1.0f - t) * tex_su + t * tex_eu; + tex_y = (1.0f - t) * tex_sv + t * tex_ev; + tex_z = (1.0f - t) * tex_sz + t * tex_ez; + + if (tex_z > m_DepthBuffer[i*pge->ScreenWidth() + j]) + { + pge->Draw(j, i, spr->Sample(tex_x / tex_z, tex_y / tex_z)); + m_DepthBuffer[i*pge->ScreenWidth() + j] = tex_z; + } + + t += tstep; + } + } + } + + } + + float* GFX3D::m_DepthBuffer = nullptr; + + void GFX3D::ConfigureDisplay() + { + m_DepthBuffer = new float[pge->ScreenWidth() * pge->ScreenHeight()]{ 0 }; + } + + + void GFX3D::ClearDepth() + { + memset(m_DepthBuffer, 0, pge->ScreenWidth() * pge->ScreenHeight() * sizeof(float)); + } + + + + + GFX3D::PipeLine::PipeLine() + { + + } + + void GFX3D::PipeLine::SetProjection(float fFovDegrees, float fAspectRatio, float fNear, float fFar, float fLeft, float fTop, float fWidth, float fHeight) + { + matProj = GFX3D::Math::Mat_MakeProjection(fFovDegrees, fAspectRatio, fNear, fFar); + fViewX = fLeft; + fViewY = fTop; + fViewW = fWidth; + fViewH = fHeight; + } + + void GFX3D::PipeLine::SetCamera(olc::GFX3D::vec3d &pos, olc::GFX3D::vec3d &lookat, olc::GFX3D::vec3d &up) + { + matView = GFX3D::Math::Mat_PointAt(pos, lookat, up); + matView = GFX3D::Math::Mat_QuickInverse(matView); + } + + void GFX3D::PipeLine::SetTransform(olc::GFX3D::mat4x4 &transform) + { + matWorld = transform; + } + + void GFX3D::PipeLine::SetTexture(olc::Sprite *texture) + { + sprTexture = texture; + } + + void GFX3D::PipeLine::SetLightSource(olc::GFX3D::vec3d &pos, olc::GFX3D::vec3d &dir, olc::Pixel &col) + { + + } + + uint32_t GFX3D::PipeLine::Render(std::vector &triangles, uint32_t flags) + { + // Calculate Transformation Matrix + mat4x4 matWorldView = Math::Mat_MultiplyMatrix(matWorld, matView); + //matWorldViewProj = Math::Mat_MultiplyMatrix(matWorldView, matProj); + + // Store triangles for rastering later + std::vector vecTrianglesToRaster; + + int nTriangleDrawnCount = 0; + + // Process Triangles + for (auto &tri : triangles) + { + GFX3D::triangle triTransformed; + + // Just copy through texture coordinates + triTransformed.t[0] = { tri.t[0].x, tri.t[0].y, tri.t[0].z }; + triTransformed.t[1] = { tri.t[1].x, tri.t[1].y, tri.t[1].z }; + triTransformed.t[2] = { tri.t[2].x, tri.t[2].y, tri.t[2].z }; // Think! + + // Transform Triangle from object into projected space + triTransformed.p[0] = GFX3D::Math::Mat_MultiplyVector(matWorldView, tri.p[0]); + triTransformed.p[1] = GFX3D::Math::Mat_MultiplyVector(matWorldView, tri.p[1]); + triTransformed.p[2] = GFX3D::Math::Mat_MultiplyVector(matWorldView, tri.p[2]); + + // Calculate Triangle Normal in WorldView Space + GFX3D::vec3d normal, line1, line2; + line1 = GFX3D::Math::Vec_Sub(triTransformed.p[1], triTransformed.p[0]); + line2 = GFX3D::Math::Vec_Sub(triTransformed.p[2], triTransformed.p[0]); + normal = GFX3D::Math::Vec_CrossProduct(line1, line2); + normal = GFX3D::Math::Vec_Normalise(normal); + + // Cull triangles that face away from viewer + if (flags & RENDER_CULL_CW && GFX3D::Math::Vec_DotProduct(normal, triTransformed.p[0]) > 0.0f) continue; + if (flags & RENDER_CULL_CCW && GFX3D::Math::Vec_DotProduct(normal, triTransformed.p[0]) < 0.0f) continue; + + // If Lighting, calculate shading + triTransformed.col = olc::WHITE; + + // Clip triangle against near plane + int nClippedTriangles = 0; + triangle clipped[2]; + nClippedTriangles = GFX3D::Math::Triangle_ClipAgainstPlane({ 0.0f, 0.0f, 0.1f }, { 0.0f, 0.0f, 1.0f }, triTransformed, clipped[0], clipped[1]); + + // This may yield two new triangles + for (int n = 0; n < nClippedTriangles; n++) + { + triangle triProjected = clipped[n]; + + // Project new triangle + triProjected.p[0] = GFX3D::Math::Mat_MultiplyVector(matProj, clipped[n].p[0]); + triProjected.p[1] = GFX3D::Math::Mat_MultiplyVector(matProj, clipped[n].p[1]); + triProjected.p[2] = GFX3D::Math::Mat_MultiplyVector(matProj, clipped[n].p[2]); + + // Apply Projection to Verts + triProjected.p[0].x = triProjected.p[0].x / triProjected.p[0].w; + triProjected.p[1].x = triProjected.p[1].x / triProjected.p[1].w; + triProjected.p[2].x = triProjected.p[2].x / triProjected.p[2].w; + + triProjected.p[0].y = triProjected.p[0].y / triProjected.p[0].w; + triProjected.p[1].y = triProjected.p[1].y / triProjected.p[1].w; + triProjected.p[2].y = triProjected.p[2].y / triProjected.p[2].w; + + triProjected.p[0].z = triProjected.p[0].z / triProjected.p[0].w; + triProjected.p[1].z = triProjected.p[1].z / triProjected.p[1].w; + triProjected.p[2].z = triProjected.p[2].z / triProjected.p[2].w; + + // Apply Projection to Tex coords + triProjected.t[0].x = triProjected.t[0].x / triProjected.p[0].w; + triProjected.t[1].x = triProjected.t[1].x / triProjected.p[1].w; + triProjected.t[2].x = triProjected.t[2].x / triProjected.p[2].w; + + triProjected.t[0].y = triProjected.t[0].y / triProjected.p[0].w; + triProjected.t[1].y = triProjected.t[1].y / triProjected.p[1].w; + triProjected.t[2].y = triProjected.t[2].y / triProjected.p[2].w; + + triProjected.t[0].z = 1.0f / triProjected.p[0].w; + triProjected.t[1].z = 1.0f / triProjected.p[1].w; + triProjected.t[2].z = 1.0f / triProjected.p[2].w; + + // Clip against viewport in screen space + // 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 sclipped[2]; + std::list listTriangles; + + + // Add initial triangle + listTriangles.push_back(triProjected); + 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 = GFX3D::Math::Triangle_ClipAgainstPlane({ 0.0f, -1.0f, 0.0f }, { 0.0f, 1.0f, 0.0f }, test, sclipped[0], sclipped[1]); break; + case 1: nTrisToAdd = GFX3D::Math::Triangle_ClipAgainstPlane({ 0.0f, +1.0f, 0.0f }, { 0.0f, -1.0f, 0.0f }, test, sclipped[0], sclipped[1]); break; + case 2: nTrisToAdd = GFX3D::Math::Triangle_ClipAgainstPlane({ -1.0f, 0.0f, 0.0f }, { 1.0f, 0.0f, 0.0f }, test, sclipped[0], sclipped[1]); break; + case 3: nTrisToAdd = GFX3D::Math::Triangle_ClipAgainstPlane({ +1.0f, 0.0f, 0.0f }, { -1.0f, 0.0f, 0.0f }, test, sclipped[0], sclipped[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(sclipped[w]); + } + nNewTriangles = listTriangles.size(); + } + + for (auto &triRaster : listTriangles) + { + // Scale to viewport + /*triRaster.p[0].x *= -1.0f; + triRaster.p[1].x *= -1.0f; + triRaster.p[2].x *= -1.0f; + triRaster.p[0].y *= -1.0f; + triRaster.p[1].y *= -1.0f; + triRaster.p[2].y *= -1.0f;*/ + vec3d vOffsetView = { 1,1,0 }; + triRaster.p[0] = Math::Vec_Add(triRaster.p[0], vOffsetView); + triRaster.p[1] = Math::Vec_Add(triRaster.p[1], vOffsetView); + triRaster.p[2] = Math::Vec_Add(triRaster.p[2], vOffsetView); + triRaster.p[0].x *= 0.5f * fViewW; + triRaster.p[0].y *= 0.5f * fViewH; + triRaster.p[1].x *= 0.5f * fViewW; + triRaster.p[1].y *= 0.5f * fViewH; + triRaster.p[2].x *= 0.5f * fViewW; + triRaster.p[2].y *= 0.5f * fViewH; + vOffsetView = { fViewX,fViewY,0 }; + triRaster.p[0] = Math::Vec_Add(triRaster.p[0], vOffsetView); + triRaster.p[1] = Math::Vec_Add(triRaster.p[1], vOffsetView); + triRaster.p[2] = Math::Vec_Add(triRaster.p[2], vOffsetView); + + // For now, just draw triangle + + if (flags & RENDER_TEXTURED) + { + TexturedTriangle( + triRaster.p[0].x, triRaster.p[0].y, triRaster.t[0].x, triRaster.t[0].y, triRaster.t[0].z, + triRaster.p[1].x, triRaster.p[1].y, triRaster.t[1].x, triRaster.t[1].y, triRaster.t[1].z, + triRaster.p[2].x, triRaster.p[2].y, triRaster.t[2].x, triRaster.t[2].y, triRaster.t[2].z, + sprTexture); + } + + if (flags & RENDER_WIRE) + { + DrawTriangleWire(triRaster, olc::RED); + } + + if (flags & RENDER_FLAT) + { + DrawTriangleFlat(triRaster); + } + + nTriangleDrawnCount++; + } + } + } + + return nTriangleDrawnCount; + } +} + +#endif \ No newline at end of file