From 8eb9068093307b2391bc98822bf03935048c818c Mon Sep 17 00:00:00 2001
From: Doyle Thai <dyl.thai@gmail.com>
Date: Thu, 4 Aug 2016 19:42:35 +1000
Subject: [PATCH] Add notion of rect struct and button rendering

Begin switching over to using Rect instead of V4s for rectangle operations
for added semantics of pos and size, instead of 2 coordinate points. There
    are more meaningful rectangle operations based on its position and
    size. By providing that upfront it's more intuitive and convenient
    than deducing size from subtracting two vector elements.
---
 src/WorldTraveller.c                 | 63 +++++++++++++++++++++++++++-
 src/include/Dengine/Math.h           |  6 +++
 src/include/Dengine/WorldTraveller.h |  3 +-
 3 files changed, 69 insertions(+), 3 deletions(-)

diff --git a/src/WorldTraveller.c b/src/WorldTraveller.c
index 2236b8e..ce57f03 100644
--- a/src/WorldTraveller.c
+++ b/src/WorldTraveller.c
@@ -82,6 +82,9 @@ INTERNAL void rendererInit(GameState *state, v2 windowSize)
 // TODO(doyle): Remove and implement own random generator!
 #include <time.h>
 #include <stdlib.h>
+
+GLOBAL_VAR UiState uiState = {0};
+
 void worldTraveller_gameInit(GameState *state, v2 windowSize)
 {
 	AssetManager *assetManager = &state->assetManager;
@@ -342,6 +345,9 @@ void worldTraveller_gameInit(GameState *state, v2 windowSize)
 #endif
 
 	srand(CAST(u32)(time(NULL)));
+
+	uiState.mouseP      = &state->input.mouse;
+	uiState.mouseIsDown = &state->input.mouseLeft;
 }
 
 INTERNAL inline v4 getEntityScreenRect(Entity entity)
@@ -609,7 +615,6 @@ INTERNAL inline void resetEntityState(World *world, Entity *entity)
 	entity->stats->entityIdToAttack = ENTITY_NULL_ID;
 }
 
-
 INTERNAL registerEvent(EventQueue *eventQueue, enum EventType type, void *data)
 {
 #ifdef DENGINE_DEBUG
@@ -620,6 +625,7 @@ INTERNAL registerEvent(EventQueue *eventQueue, enum EventType type, void *data)
 	eventQueue->queue[currIndex].type = type;
 	eventQueue->queue[currIndex].data = data;
 }
+
 INTERNAL void entityStateSwitch(EventQueue *eventQueue, World *world,
                                 Entity *entity, enum EntityState newState)
 {
@@ -876,7 +882,49 @@ INTERNAL void sortWorldEntityList(World *world, i32 numDeadEntities)
 	world->freeEntityIndex -= numDeadEntities;
 }
 
-UiState uiState = {0};
+INTERNAL b32 pointInRect(Rect rect, v2 point)
+{
+	if (point.x < rect.pos.x || point.x > rect.pos.x + rect.size.w ||
+	    point.y > rect.pos.y + rect.size.h || point.y < rect.pos.y)
+		return FALSE;
+	return TRUE;
+}
+
+i32 button(AssetManager *assetManager, Renderer *renderer, i32 id, Rect rect,
+           v2 mouseP)
+{
+	if (pointInRect(rect, mouseP))
+	{
+		uiState.hotItem = id;
+		if (uiState.activeItem == 0 && uiState.mouseIsDown)
+			uiState.activeItem = id;
+	}
+
+	RenderTex renderTex = renderer_createNullRenderTex(assetManager);
+	renderer_staticRect(renderer, v2_add(V2(8, 8), rect.pos), rect.size,
+	                    V2(0, 0), 0, renderTex, V4(0, 0, 0, 1));
+	if (uiState.hotItem == id)
+	{
+		if (uiState.activeItem == id)
+		{
+			renderer_staticRect(renderer, v2_add(V2(2, 2), rect.pos), rect.size,
+			                    V2(0, 0), 0, renderTex, V4(1, 1, 1, 1));
+		}
+		else
+		{
+			renderer_staticRect(renderer, v2_add(V2(0, 0), rect.pos), rect.size,
+			                    V2(0, 0), 0, renderTex, V4(1, 1, 1, 1));
+		}
+	}
+	else
+	{
+		renderer_staticRect(renderer, v2_add(V2(0, 0), rect.pos), rect.size,
+		                    V2(0, 0), 0, renderTex, V4(0.5f, 0.5f, 0.5f, 1));
+	}
+
+	return 0;
+}
+
 void worldTraveller_gameUpdateAndRender(GameState *state, f32 dt)
 {
 	if (dt >= 1.0f) dt = 1.0f;
@@ -1128,6 +1176,17 @@ void worldTraveller_gameUpdateAndRender(GameState *state, f32 dt)
 	renderer_staticRect(renderer, state->input.mouse, hero->hitboxSize,
 	                    V2(0, 0), 0, nullRenderTex, V4(0.5f, 0, 0, 0.5f));
 
+#if 0
+	RenderTex renderTex = renderer_createNullRenderTex(assetManager);
+	v2 buttonP = V2(500, 500);
+	v2 buttonSize = V2(100, 100);
+	renderer_staticRect(renderer, v2_add(V2(8, 8), buttonP), buttonSize,
+	                    V2(0, 0), 0, renderTex, V4(0, 0, 0, 1));
+#endif
+
+	Rect buttonRect = {V2(500, 500), V2(100, 100)};
+	button(assetManager, renderer, 1, buttonRect, *uiState.mouseP);
+
 	/* Draw hero avatar */
 	TexAtlas *heroAtlas  = asset_getTextureAtlas(assetManager, texlist_hero);
 	v4 heroAvatarTexRect = heroAtlas->texRect[herorects_head];
diff --git a/src/include/Dengine/Math.h b/src/include/Dengine/Math.h
index b1dc035..43b7bdb 100644
--- a/src/include/Dengine/Math.h
+++ b/src/include/Dengine/Math.h
@@ -45,6 +45,12 @@ typedef union v4
 	f32 e[4];
 } v4;
 
+typedef struct Rect
+{
+	v2 pos;
+	v2 size;
+} Rect;
+
 INTERNAL inline v2 V2i(const i32 x, const i32 y)
 {
 	v2 result = {CAST(f32)x, CAST(f32)y};
diff --git a/src/include/Dengine/WorldTraveller.h b/src/include/Dengine/WorldTraveller.h
index 56d3e3c..c5bbd31 100644
--- a/src/include/Dengine/WorldTraveller.h
+++ b/src/include/Dengine/WorldTraveller.h
@@ -15,6 +15,8 @@
 
 typedef struct UiState
 {
+	v2 *mouseP;
+	b32 *mouseIsDown;
 	i32 hotItem;
 	i32 activeItem;
 } UiState;
@@ -53,7 +55,6 @@ typedef struct GameState
 	AssetManager assetManager;
 	AudioManager audioManager;
 	MemoryArena arena;
-	UiState uiState;
 } GameState;
 
 void worldTraveller_gameInit(GameState *state, v2 windowSize);