first commit

3 files changed, 175 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..ae07e71
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+*.ppm
+render
diff --git a/main.cpp b/main.cpp
new file mode 100755
index 0000000..9b1ce8c
--- /dev/null
+++ b/main.cpp
@@ -0,0 +1,162 @@
+#include<fstream>
+#include<cmath>
+
+class Vertice
+{
+public:
+	float x, y, z;
+	unsigned char red, green, blue;
+	Vertice(float x, float y, float z, int red, int green, int blue)
+	{
+		this->x = x;
+		this->y = y;
+		this->z = z;
+
+		this->red = (unsigned char)red;
+		this->green = (unsigned char)green;
+		this->blue = (unsigned char)blue;
+	}
+	void fitToImage(int imageWidth, int imageHeight)
+	{
+		x = (x * (imageWidth / 2)) + (imageWidth / 2);
+		y = (-y * (imageHeight / 2)) + (imageHeight / 2);
+	}
+};
+
+class Image
+{
+public:
+	int imageWidth, imageHeight;
+	unsigned char* pixels;
+	Image(int imageWidth, int imageHeight)
+	{
+		this->imageWidth = imageWidth;
+		this->imageHeight = imageHeight;
+		pixels = new unsigned char[imageWidth * imageHeight * 3];
+	}
+	~Image()
+	{
+		delete[] pixels;
+	}
+	void setPixel(int x, int y, int red, int green, int blue)
+	{
+		int help_var = ((y * imageWidth) + x) * 3;
+		pixels[help_var + 0] = (unsigned char)red;
+		pixels[help_var + 1] = (unsigned char)green;
+		pixels[help_var + 2] = (unsigned char)blue;
+	}
+	void fillPixels(int red, int green, int blue)
+	{
+		int help_var = imageWidth * imageHeight * 3;
+		for (int i = 0; i < help_var; i += 3) {
+			pixels[i + 0] = (unsigned char)red;
+			pixels[i + 1] = (unsigned char)green;
+			pixels[i + 2] = (unsigned char)blue;
+		}
+	}
+	//-------------------SCANLINE TRIANGLE RASTERISATION---------------------------
+	void fillFlatTopTriangle(Vertice* v1, Vertice* v2, Vertice* v3)
+	{
+		float invslope1 = (float)(v3->x - v1->x) / (float)(v3->y - v1->y);
+		float invslope2 = (float)(v3->x - v2->x) / (float)(v3->y - v2->y);
+
+		float curx1 = v3->x;
+		float curx2 = v3->x;
+		int cury1 = (int)ceil(v1->y - 0.5f);
+		int cury2 = (int)ceil(v3->y - 0.5f);
+
+		for (int i = cury2; i >= cury1; i--)
+		{
+			if(curx1 < curx2)
+				for (int j = (int)ceil(curx1 - 0.5f); j <= (int)ceil(curx2 - 0.5f); j++)
+					setPixel(j, i, 255, 0, 0);
+			else
+				for (int j = (int)ceil(curx2 - 0.5f); j <= (int)ceil(curx1 - 0.5f); j++)
+					setPixel(j, i, 255, 0, 0);
+
+			curx1 -= invslope1;
+			curx2 -= invslope2;
+		}
+	}
+	void fillFlatBottomTriangle(Vertice* v1, Vertice* v2, Vertice* v3)
+	{
+		float invslope1 = (float)(v2->x - v1->x) / (float)(v2->y - v1->y);
+		float invslope2 = (float)(v3->x - v1->x) / (float)(v3->y - v1->y);
+
+		float curx1 = v1->x;
+		float curx2 = v1->x;
+		int cury1 = (int)ceil(v1->y - 0.5f);
+		int cury2 = (int)ceil(v2->y - 0.5f);
+		for (int i = cury1; i <= cury2; i++)
+		{
+			if(curx1 < curx2)
+				for (int j = (int)ceil(curx1 - 0.5f); j <= (int)ceil(curx2 - 0.5f); j++)
+					setPixel(j, i, 255, 0, 0);
+			else
+				for (int j = (int)ceil(curx2 - 0.5f); j <= (int)ceil(curx1 - 0.5f); j++)
+					setPixel(j, i, 255, 0, 0);
+
+			curx1 += invslope1;
+			curx2 += invslope2;
+		}
+	}
+	void fillTriangle(Vertice* v1, Vertice* v2, Vertice* v3)
+	{
+		if (v1->y > v2->y)
+			std::swap(v1, v2);
+		if (v1->y > v3->y)
+			std::swap(v1, v3);
+		if (v2->y > v3->y)
+			std::swap(v2, v3);
+
+		if (v2->y == v3->y){
+			if(v2->x < v3->x)
+				std::swap(v2, v3);
+			fillFlatBottomTriangle(v1, v2, v3);
+		}
+		else if (v1->y == v2->y){
+			if(v1->x < v2->x)
+				std::swap(v1, v2);
+			fillFlatTopTriangle(v1, v2, v3);
+		}
+		else
+		{
+			Vertice v4(
+				(v1->x + (((float)(v2->y - v1->y) / (float)(v3->y - v1->y)) * (v3->x - v1->x))), v2->y, 0.0f, 0, 0, 0);
+			if(v1->x < v4.x){
+				fillFlatBottomTriangle(v1, v2, &v4);
+				fillFlatTopTriangle(v2, &v4, v3);
+			}
+			else{
+				fillFlatBottomTriangle(v1, &v4, v2);
+				fillFlatTopTriangle(&v4, v2, v3);
+			}
+		}
+
+	}
+	//-----------------------------------------------------------------------------
+};
+
+int main()
+{
+	Image image(800, 600);
+	image.fillPixels(255, 255, 255);
+
+	Vertice a(0.2f, 0.5f, 0.0f, 255, 0, 0);
+	Vertice b(-0.5f, 0.0f, 0.0f, 0, 255, 0);
+	Vertice c(0.5f, -0.5f, 0.0f, 0, 0, 255);
+
+	a.fitToImage(image.imageWidth, image.imageHeight);
+	b.fitToImage(image.imageWidth, image.imageHeight);
+	c.fitToImage(image.imageWidth, image.imageHeight);
+	
+	image.fillTriangle(&a, &b, &c);
+
+	std::ofstream imageFile;
+	imageFile.open("./image.ppm");
+	imageFile << "P6\n" << image.imageWidth << " " << image.imageHeight << "\n255\n";
+	imageFile.write((char*)image.pixels, image.imageWidth * image.imageHeight * 3);
+	imageFile.close();
+
+	return 0;
+}
diff --git a/makefile b/makefile
new file mode 100644
index 0000000..0a4fca9
--- /dev/null
+++ b/makefile
@@ -0,0 +1,11 @@
+render: main.cpp
+	g++ -o render main.cpp
+image.ppm: render
+	./render
+run: render
+	./render
+view: image.ppm
+	feh -. image.ppm
+clean:
+	rm image.ppm
+	rm render