From 4acd6c071042f95b99ecbdf6c675c1a0beb339cb Mon Sep 17 00:00:00 2001
From: Edgaru089 <sjs333@outlook.com>
Date: Mon, 22 Apr 2024 04:50:06 +0800
Subject: [PATCH] Add polygon fills

---
 app_file.c         | 19 +++++++++++++++++++
 app_render.cpp     | 25 +++++++++++++++++++++++--
 render_component.c |  3 +++
 render_component.h |  6 ++++--
 4 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/app_file.c b/app_file.c
index 9b1fad4..3585639 100644
--- a/app_file.c
+++ b/app_file.c
@@ -188,6 +188,25 @@ static void _app_LevelCommand(App *app, char *cmd) {
 		e->render->fillbox   = box;
 		e->render->fillcolor = color;
 	}
+	CMD("FILLPOLY") {
+		uint32_t color = readcolor();
+		int      n     = TOKEN_INT;
+
+		// Allocate a Vector
+		vector_Vector *vec = vector_Create(sizeof(Vec2));
+		vector_Reserve(vec, n);
+
+		// Read N points
+		for (int i = 0; i < n; i++) {
+			Vec2 point = readvec2();
+			vector_Push(vec, &point);
+		}
+
+		Entity *e = entity_Create(app->entity, cmd);
+		ADD_COMPONENT(e, render);
+		e->render->fillpoly  = vec; // Deallocated in render_DeleteComponent
+		e->render->fillcolor = color;
+	}
 
 	else {
 		WARN("unknown command \"%s\"", cmd);
diff --git a/app_render.cpp b/app_render.cpp
index 2dd4991..fc9907b 100644
--- a/app_render.cpp
+++ b/app_render.cpp
@@ -10,6 +10,7 @@
 #include "util/tree.h"
 #include "types.h"
 #include "render_util.h"
+#include "util/vector.h"
 #include <math.h>
 #include <graphics.h>
 
@@ -27,7 +28,7 @@ void app_Render(App *app) {
 	setbkcolor(app->clear_color);
 	cleardevice();
 
-	// Draw fill boxes first
+	// Draw fill polys & boxes first
 	for (tree_Node *i = tree_FirstNode(app->entity->entities);
 		 i != NULL;
 		 i = tree_Node_Next(i)) {
@@ -39,9 +40,29 @@ void app_Render(App *app) {
 			Vec2 pos = {.x = 0.0, .y = 0.0};
 			if (e->position)
 				pos = e->position->position;
+
+			// Has fill polygon
+			if (r->fillpoly) {
+				static vector_Vector *buf = vector_Create(2 * sizeof(int));
+				vector_Clear(buf);
+
+				// Transform every point in the polygon
+				for (int i = 0; i < vector_Size(r->fillpoly); i++) {
+					Vec2 screen_point        = camera_TransformVec2(app->camera, vec2_Add(*(Vec2 *)vector_At(r->fillpoly, i), pos));
+					int  screen_point_int[2] = {
+                        (int)round(screen_point.x),
+                        (int)round(screen_point.y)};
+					vector_Push(buf, screen_point_int);
+				}
+
+				// Draw
+				setfillcolor(r->fillcolor);
+				solidpolygon((POINT *)vector_Data(buf), vector_Size(r->fillpoly));
+			}
+
 			// Has fillbox
 			if (r->fillbox.size.x > EPS) {
-				Box2 cam = camera_TransformBox2(app->camera, r->fillbox);
+				Box2 cam = camera_TransformBox2(app->camera, box2_Offset(r->fillbox, pos));
 				setfillcolor(r->fillcolor);
 				solidrectangle(
 					(int)round(cam.lefttop.x),
diff --git a/render_component.c b/render_component.c
index 8d97d3c..e66ac03 100644
--- a/render_component.c
+++ b/render_component.c
@@ -3,6 +3,7 @@
 #include "app.h"
 #include "render_bundle.h"
 #include "types.h"
+#include "util/vector.h"
 
 
 Component_Render *render_NewComponent(Entity *super, const char *bundle_name) {
@@ -25,5 +26,7 @@ Component_Render *render_NewComponentFunc(Entity *super, render_CustomFunc func,
 }
 
 void render_DeleteComponent(Component_Render *r) {
+	if (r->fillpoly)
+		vector_Destroy(r->fillpoly);
 	free(r);
 }
diff --git a/render_component.h b/render_component.h
index 0a452df..933a817 100644
--- a/render_component.h
+++ b/render_component.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include "util/vector.h"
 #include "render_bundle.h"
 
 
@@ -21,8 +22,9 @@ typedef struct {
 	render_CustomFunc custom;      // Custom rendering function
 	void             *custom_data; // User data for the callback
 
-	Box2     fillbox;   // Fill box
-	uint32_t fillcolor; // Fill color
+	Box2           fillbox;   // Fill box
+	vector_Vector *fillpoly;  // Fill polygon, vector of Vec2
+	uint32_t       fillcolor; // Fill color
 } Component_Render;