逐像素渲染

Scene.cpp

@@ -2,19 +2,45 @@
 #include "util.h"
 #include "Camera.h"
 #include "Ray.h"
-
+#pragma comment(lib, "winmm.lib")
+static int sTotalPixelCount = 0;
+static int sViewportWidth = 0, sViewportHeight = 0;
 void Init(int width, int height)
 {
-	for (int x = 0; x < height; x++) {
-		for (int y = 0; y < width; y++) {
-			SetColor(y, x, 255, 0, 0, 255);
-		}
-	}
+	sTotalPixelCount = width * height;
+	sViewportWidth = width;
+	sViewportHeight = height;
 	Camera camera(45.0f, float(width) / float(height));
 	camera.LookAt(Vector3(0.0f,0.0f,1.0f), Vector3(0.0f,0.0f,0.0f), Vector3(0.0f,1.0f,0.0f));
 	Ray ray = camera.GetRay(0.5f, 0.5f);
 }
 
+float GetEscaptedTime() {
+	static unsigned long sTimeSinceComputerStart = 0;
+	static unsigned long sLastFrameTime = 0;
+	sTimeSinceComputerStart = timeGetTime();
+	unsigned long frame_time = sLastFrameTime == 0 ? 0 : sTimeSinceComputerStart - sLastFrameTime;
+	sLastFrameTime = sTimeSinceComputerStart;
+
+	return float(frame_time) / 1000.0f;
+}
+
+void RenderOnePixel(int pixel_index) {
+	int x = pixel_index % sViewportWidth;
+	int y = pixel_index / sViewportWidth;
+	SetColor(x, y, 255, 255, 0, 255);
+}
+
 void Render()
 {
+	static int sCurrentRenderPixel = 0;
+	float current_render_time = 0.0f;
+	while (sCurrentRenderPixel < sTotalPixelCount) {
+		RenderOnePixel(sCurrentRenderPixel);
+		sCurrentRenderPixel++;
+		current_render_time = GetEscaptedTime();
+		if (true || current_render_time > 0.033f) {
+			break;
+		}
+	}
 }