fixes for polygon/cone fill

src/hexgame.cpp

@@ -1,13 +1,14 @@
 
 // Some defaults for the game layout
-#define HEX_SIZE 20
-#define HEX_RADIUS 9
+#define HEX_SIZE 10
+#define HEX_RADIUS 19
 #define HEX_ORIENTATION layout_flat
 #define FILL_COLOR 0x565656FF
 #define SELECTED_FILL_COLOR 0xF46000FF
 #define DEBUG_DRAW true
 #define VIEWPORT_WIDTH 1280
 #define VIEWPORT_HEIGHT 720
+#define CONE_ANGLE 30
 
 
 #include <string>
@@ -31,6 +32,7 @@ using std::vector;
 
 game_state* g_game_state;
 render_state* g_render_state;
+vector<Point> g_polygon_select_vertices = {Point(), Point(), Point(), Point()};
 
 void
 createHexes(vector<hex_info> *hxi_array, const Layout &layout, uint32 color)
@@ -182,7 +184,7 @@ updateHexConeFill(int32 x, int32 y)
 		Point p2(g_game_state->current_hex->XPos, g_game_state->current_hex->YPos);
 		real64 angle = std::atan2(p2.y - p1.y, p2.x - p1.x);
 		real64 len = std::hypot(p2.y - p1.y, p2.x - p1.x);
-		real64 coneAngle = 30.f * M_PI / 180; // M_PI is non-standard and may not be portable
+		real64 coneAngle = CONE_ANGLE * M_PI / 180; // M_PI is non-standard and may not be portable
 		
 		real64 x1 = len * std::cos(angle);
 		real64 y1 = len * std::sin(angle);
@@ -193,33 +195,32 @@ updateHexConeFill(int32 x, int32 y)
 		real64 botX = x1 * std::cos(coneAngle) + y1 * std::sin(coneAngle) + p1.x;
 		real64 botY = x1 * std::sin(-1 * coneAngle) + y1 * std::cos(coneAngle) + p1.y;
 
-		hex_info* topHex = getSingleHex(topX, topY);
-		hex_info* botHex = getSingleHex(botX, botY);
+		Point test_p;
+		Point vert2 = Point(botX, botY);
+		Point vert4 = Point(topX, topY);
+		std::vector<Point> vertices = {p1, vert2, p2, vert4};
 
-		if (topHex && botHex)
+		for (hex_info &h : *g_game_state->hex_array)
 		{
-			Point test_p;
-			Point vert2 = Point(botHex->XPos, botHex->YPos);
-			Point vert4 = Point(topHex->XPos, topHex->YPos);
-			std::vector<Point> vertices = {p1, vert2, p2, vert4};
+			test_p.x = h.XPos;
+			test_p.y = h.YPos;
 
-			for (hex_info &h : *g_game_state->hex_array)
+			if (crossingTest(vertices, test_p))
 			{
-				test_p.x = h.XPos;
-				test_p.y = h.YPos;
-
-				if (crossingTest(vertices, test_p))
-				{
-					h.selected = true;
-					h.current_color = g_render_state->selected_fill_color;
-				}
-				else
-				{
-					h.selected = false;
-					h.current_color = h.stored_color;
-				}
+				h.selected = true;
+				h.current_color = g_render_state->selected_fill_color;
+			}
+			else
+			{
+				h.selected = false;
+				h.current_color = h.stored_color;
 			}
 		}
+
+		g_polygon_select_vertices[0].x = p1.x; g_polygon_select_vertices[0].y = p1.y;
+		g_polygon_select_vertices[1].x = vert2.x; g_polygon_select_vertices[1].y = vert2.y;
+		g_polygon_select_vertices[2].x = p2.x; g_polygon_select_vertices[2].y = p2.y;
+		g_polygon_select_vertices[3].x = vert4.x; g_polygon_select_vertices[3].y = vert4.y;
 	}
 }
 
@@ -475,7 +476,7 @@ int main(int argc, char* argv[])
 		SDL_Delay(16);	// ~60hz
 		renderFrame(g_game_state->hex_array);
 		if (g_render_state->is_debug_draw && g_game_state->draw_mode == CONE_FILL)
-			renderDebug(g_game_state->start_hex, g_game_state->current_hex);
+			renderDebug(g_polygon_select_vertices);
 		renderGooey(handles, g_game_state->draw_mode, g_render_state->is_debug_draw,
 					g_game_state->start_hex, g_game_state->current_hex, g_game_state->is_selecting);
 		SDL_GL_SwapWindow(handles.window);

src/hexlib.h

@@ -299,27 +299,15 @@ crossingTest(vector<Point> vertices, Point p)
 			vert1 = vertices[0];
 		else
 			vert1 = vertices[i];
- 
+
 		// check if edge can intersect the +X ray
-		if ((vert0.y >= p.y && vert1.y <= p.y) ||
-			(vert0.y <= p.y && vert1.y >= p.y))
+		// NOTE: upward/downward crossing excludes one vertex in the case that
+		// 	the ray intersects a vertex
+		if ((vert0.y > p.y && vert1.y <= p.y) || // downward crossing
+			(vert0.y <= p.y && vert1.y > p.y))	// upward crossing
 		{
-			// TODO: these checks for undefined is pretty hacky
-			double dx = vert1.x - vert0.x;
-			// solve for point on edge where y = p.y
-			if (dx == 0) // don't divide by zero
-				x = (vert0.x == 0) ? 1 : vert0.x;
-			else
-			{
-				double dm = vert1.x - vert0.x;
-				if (dm == 0) // don't divide by 0
-					x = (vert0.x == 0) ? 1 : vert0.x;
-				else
-				{
-					m = (vert1.y - vert0.y) / (dm);
-					x = (p.y - vert0.y) / m + vert0.x;
-				}
-			}
+			m = (vert1.y - vert0.y) / (vert1.x - vert0.x);
+			x = (p.y - vert0.y) / m + vert0.x;
 			// if x is right of p.x it must intersect
 			if (x >= p.x)
 				intersect_count++;

src/renderer.h

@@ -100,7 +100,7 @@ bool initRenderer(SDL_Handles &handles, v2i vpDims);
 bool addTexture(SDL_Handles &handles, std::string path);
 bool createScene(std::vector<hex_info>* hexes);
 void renderFrame(const std::vector<hex_info> *hexes);
-void renderDebug(hex_info *start_hex, hex_info * current_hex);
+void renderDebug(std::vector<Point> &vertices);
 void freeBuffers();
 
 // forward declarations
@@ -518,37 +518,14 @@ renderFrame(std::vector<hex_info> *hexes)
 }
 
 void
-renderDebug(hex_info *start_hex, hex_info *current_hex)
+renderDebug(std::vector<Point> &vertices)
 {
-	if (!start_hex || !current_hex)
-		return;
-
-	// fill vertex buffer
-	Point p1(start_hex->XPos, start_hex->YPos);
-	Point p2(current_hex->XPos, current_hex->YPos);
-	real64 angle = std::atan2(p2.y - p1.y, p2.x - p1.x);
-	real64 len = std::hypot(p2.y - p1.y, p2.x - p1.x);
-	real64 coneAngle = 30.f * M_PI / 180; // M_PI is non-standard and may not be portable
-	
-	// TODO: add matrix math library for rotation transform?
-	// |x|   | cos(a + b) -sin(a + b)  0 |
-	// |y| * | sin(a + b)  cos(a + b)  0 |
-	// |0|   | 0           0           1 |
-	//
-	real64 x1 = len * std::cos(angle);
-	real64 y1 = len * std::sin(angle);
-	// top of cone
-	real64 topX = x1 * std::cos(coneAngle) - y1 * std::sin(coneAngle) + p1.x;
-	real64 topY = x1 * std::sin(coneAngle) + y1 * std::cos(coneAngle) + p1.y;
-	// bottom of cone
-	real64 botX = x1 * std::cos(coneAngle) + y1 * std::sin(coneAngle) + p1.x;
-	real64 botY = x1 * std::sin(-1 * coneAngle) + y1 * std::cos(coneAngle) + p1.y;
 	// TODO: indexed line drawing
 	real64 buf[4 * 3] = {
-		p1.x, p1.y, 0,
-		botX, botY, 0,
-		p2.x, p2.y, 0,
-		topX, topY, 0,
+		vertices[0].x, vertices[0].y, 0,
+		vertices[1].x, vertices[1].y, 0,
+		vertices[2].x, vertices[2].y, 0,
+		vertices[3].x, vertices[3].y, 0,
 	};
 
 	// copy vertexes to render group