init

src/Rasterizer/Rasterizer.cpp

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+#include "Rasterizer.h"
+#include <Vector2.h>
+#include "Color.h"
+#include <cmath>
+#include <cstdint>
+
+namespace Rasterizer
+{
+	using namespace Math;
+	using namespace RenderData;
+
+	void Rasterizer::DrawLineHorizontal(const Vector2Int v0, const Vector2Int v1, const Color color)
+	{
+		Vector2Int start = v0, end = v1;
+		if (v0.x > v1.x)
+		{
+			start = v1;
+			end = v0;
+		}
+
+		int32_t dx = end.x - start.x;
+		int32_t dy = end.y - start.y;
+
+		int32_t dir = dy < 0 ? -1 : 1;
+		dy *= dir;
+
+		if (dx == 0) return;
+
+		int32_t y = start.y;
+		int32_t p = 2 * dy - dx;
+		for (int32_t x = start.x; x <= end.x; x++)
+		{
+			frameBuffer->set_pixel(x, y, color.to_rgba());
+			// 当 p >= 0 时，取上方像素点
+			if (p >= 0)
+			{
+				y += dir;
+				p -= 2 * dx;
+			}
+			// 当 p < 0 时，取下方像素点
+			p += 2 * dy;
+		}
+	}
+
+	void Rasterizer::DrawLineVertical(const Vector2Int v0, const Vector2Int v1, const Color color)
+	{
+		Vector2Int start = v0, end = v1;
+		if (v0.y > v1.y)
+		{
+			start = v1;
+			end = v0;
+		}
+
+		int32_t dx = end.x - start.x;
+		int32_t dy = end.y - start.y;
+
+		int32_t dir = dx < 0 ? -1 : 1;
+		dx *= dir;
+
+		if (dy == 0) return;
+
+		int32_t x = start.x;
+		int32_t p = 2 * dx - dy;
+		for (int32_t y = start.y; y <= end.y; y++)
+		{
+			frameBuffer->set_pixel(x, y, color.to_rgba());
+			// 当 p >= 0 时，取上方像素点
+			if (p >= 0)
+			{
+				x += dir;
+				p -= 2 * dy;
+			}
+			// 当 p < 0 时，取下方像素点
+			p += 2 * dx;
+		}
+	}
+
+	/// <summary>
+	/// 在给定的起始点和结束点之间绘制一条线段，并使用指定的颜色填充
+	/// </summary>
+	/// <param name="v0">直线顶点 1</param>
+	/// <param name="v1">直线顶点 2</param>
+	/// <param name="color">绘制的颜色</param>
+	/// <remarks>
+	/// bresenham 画线算法
+	/// </remarks>
+	void Rasterizer::DrawLine(const Vector2Int v0, const Vector2Int v1, const Color color)
+	{
+		int32_t x0 = v0.x, y0 = v0.y;
+		int32_t x1 = v1.x, y1 = v1.y;
+
+		if (std::abs(x1 - x0) > std::abs(y1 - y0))
+		{
+			DrawLineHorizontal(v0, v1, color);
+		}
+		else
+		{
+			DrawLineVertical(v0, v1, color);
+		}
+	}
+}
+

src/Rasterizer/Rasterizer.h

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+#pragma once
+#include "Color.h"
+#include "FrameBuffer.h"
+#include "DepthBuffer.h"
+#include <Vector2.h>
+
+namespace Rasterizer
+{
+	class Rasterizer
+	{
+	private:
+		Core::FrameBuffer* frameBuffer;
+		Core::DepthBuffer* depthBuffer;
+
+		void DrawLineHorizontal(const Math::Vector2Int v0, const Math::Vector2Int v1, const RenderData::Color color);
+		void DrawLineVertical(const Math::Vector2Int v0, const Math::Vector2Int v1, const RenderData::Color color);
+
+	public:
+		explicit Rasterizer(Core::FrameBuffer* frameBuffer) :frameBuffer(frameBuffer), depthBuffer(nullptr) {}
+		explicit Rasterizer(Core::FrameBuffer* frameBuffer, Core::DepthBuffer* depthBuffer) :frameBuffer(frameBuffer), depthBuffer(depthBuffer) {}
+
+		void DrawLine(const Math::Vector2Int v0, const Math::Vector2Int v1, const RenderData::Color color);
+	};
+}

src/Rasterizer/TriangleRasterizer.cpp

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+#include "TriangleRasterizer.h"
+#include <Triangle.h>
+#include <Color.h>
+#include "BoundingBox.h"
+#include <Vector2.h>
+#include <algorithm>
+#include <cstdint>
+
+namespace Rasterizer
+{
+	void TriangleRasterizer::DrawTriangle2D(const RenderData::Triangle& triangle, const RenderData::Color color)
+	{
+		using namespace Math;
+
+		auto boundingBox = triangle.get_boundingBox();
+
+		int32_t minX = std::max(0, boundingBox.min.x);
+		int32_t maxX = std::min(frameBuffer->get_width() - 1, boundingBox.max.x);
+		int32_t minY = std::max(0, boundingBox.min.y);
+		int32_t maxY = std::min(frameBuffer->get_height() - 1, boundingBox.max.y);
+
+		for (int x = minX; x <= maxX; x++)
+		{
+			for (int y = minY; y <= maxY; y++)
+			{
+				Vector2 samplePoint(x + 0.5f, y + 0.5f);
+				float w0 = 0, w1 = 0, w2 = 0;
+				if (!triangle.get_barycentric(samplePoint, w0, w1, w2))
+				{
+					continue;
+				}
+
+				if ((w0 < 0) || (w1 < 0) || (w2 < 0))
+				{
+					continue;
+				}
+
+				const float depth =
+					w0 * triangle.v0.position.z +
+					w1 * triangle.v1.position.z +
+					w2 * triangle.v2.position.z;
+
+				if (depthBuffer)
+				{
+					// 深度越小离相机越近
+					if (depthBuffer->get_depth(x, y) < depth)
+					{
+						continue;
+					}
+
+					depthBuffer->set_depth(x, y, depth);
+					frameBuffer->set_pixel(x, y, color.to_rgba());
+				}
+				else
+				{
+					frameBuffer->set_pixel(x, y, color.to_rgba());
+				}
+			}
+		}
+	}
+}

src/Rasterizer/TriangleRasterizer.h

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+#pragma once
+#include "Triangle.h"
+#include "Color.h"
+#include "FrameBuffer.h"
+#include <DepthBuffer.h>
+
+namespace Rasterizer
+{
+	class TriangleRasterizer
+	{
+	private:
+		Core::FrameBuffer* frameBuffer;
+		Core::DepthBuffer* depthBuffer;
+
+
+	public:
+		explicit TriangleRasterizer(Core::FrameBuffer* frameBuffer) :frameBuffer(frameBuffer), depthBuffer(nullptr) {};
+		explicit TriangleRasterizer(Core::FrameBuffer* frameBuffer, Core::DepthBuffer* depthBuffer) :frameBuffer(frameBuffer), depthBuffer(depthBuffer) {};
+
+		void DrawTriangle2D(const RenderData::Triangle& triangle, const RenderData::Color color);
+	};
+}