Add game entity list rendering, create animations

src/WorldTraveller.c

@@ -2,9 +2,15 @@
 #include <Dengine/Math.h>
 #include <WorldTraveller/WorldTraveller.h>
 
+//TODO(doyle): This is temporary! Maybe abstract into our platform layer, or
+//choose to load assets outside of WorldTraveller!
+#include <stdlib.h>
+
 void updateBufferObject(GLuint vbo, v4 texNDC)
 {
 	// TODO(doyle): We assume that vbo and vao are assigned
+	// NOTE(doyle): Draws a series of triangles (three-sided polygons) using
+	// vertices v0, v1, v2, then v2, v1, v3 (note the order)
 	v4 vertices[] = {
 		//  x     y       s     t
 		{0.0f, 1.0f, texNDC.x, texNDC.y}, // Top left
@@ -26,19 +32,28 @@ void worldTraveller_gameInit(GameState *state)
 	/* Initialise assets */
 	asset_loadTextureImage(
 	    "data/textures/WorldTraveller/TerraSprite1024.png", texlist_hero);
-	glCheckError();
 	asset_loadShaderFiles("data/shaders/sprite.vert.glsl",
 	                      "data/shaders/sprite.frag.glsl", shaderlist_sprite);
 	glCheckError();
 
 	state->state = state_active;
-	state->heroLastDirection = direction_east;
 
 	/* Init hero */
-	Entity *hero = &state->hero;
+	SpriteAnim heroAnim = {NULL, 1, 0, 1.0f, 1.0f};
-	hero->tex    = asset_getTexture(texlist_hero);
+	// TODO(doyle): Get rid of
-	hero->size   = V2(58.0f, 98.0f);
+	heroAnim.rect = (v4 *)calloc(1, sizeof(v4));
-	hero->pos    = V2(0.0f, 0.0f);
+	heroAnim.rect[0] = V4(746.0f, 1018.0f, 804.0f, 920.0f);
+
+	Entity heroEnt = {V2(0.0f, 0.0f),
+	                  V2(0.0f, 0.0f),
+	                  V2(58.0f, 98.0f),
+	                  direction_east,
+	                  asset_getTexture(texlist_hero),
+	                  heroAnim};
+
+	state->heroIndex = state->freeEntityIndex;
+	state->entityList[state->freeEntityIndex++] = heroEnt;
+	Entity *hero = &state->entityList[state->heroIndex];
 
 	Texture *heroSheet = hero->tex;
 	v2 sheetSize = V2(CAST(f32)heroSheet->width, CAST(f32)heroSheet->height);
@@ -50,15 +65,16 @@ void worldTraveller_gameInit(GameState *state)
 		    CAST(i32) sheetSize.w, CAST(i32) sheetSize.h);
 	}
 
-	f32 ndcFactor = sheetSize.w;
+	/* Create a NPC */
-	v2 heroStartPixel = V2(746.0f, 1018.0f);
+	SpriteAnim npcAnim = {NULL, 2, 0, 0.3f, 0.3f};
-	v2 heroSizeOnSheet = V2(58.0f, 98.0f);
+	// TODO(doyle): Get rid of
-	v4 heroRect = V4(heroStartPixel.x,
+	npcAnim.rect = (v4 *)calloc(2, sizeof(v4));
-	                 heroStartPixel.y,
+	npcAnim.rect[0] = V4(944.0f, 918.0f, 1010.0f, 816.0f);
-	                 heroStartPixel.x + heroSizeOnSheet.w,
+	npcAnim.rect[1] = V4(944.0f, 812.0f, 1010.0f, 710.0f);
-	                 heroStartPixel.y - heroSizeOnSheet.h);
 
-	v4 heroTexNDC = v4_scale(heroRect, 1.0f/ndcFactor);
+	Entity npcEnt = {V2(300.0f, 300.0f), V2(0.0f, 0.0f), hero->size,
+	                 direction_null, hero->tex, npcAnim};
+	state->entityList[state->freeEntityIndex++] = npcEnt;
 
 	/* Init renderer */
 	Renderer *renderer = &state->renderer;
@@ -70,16 +86,6 @@ void worldTraveller_gameInit(GameState *state)
 	shader_uniformSetMat4fv(renderer->shader, "projection", projection);
 	glCheckError();
 
-	// NOTE(doyle): Draws a series of triangles (three-sided polygons) using
-	// vertices v0, v1, v2, then v2, v1, v3 (note the order)
-	v4 vertices[] = {
-		//  x     y       s     t
-		{0.0f, 1.0f, heroTexNDC.x, heroTexNDC.y}, // Top left
-		{0.0f, 0.0f, heroTexNDC.x, heroTexNDC.w}, // Bottom left
-		{1.0f, 1.0f, heroTexNDC.z, heroTexNDC.y}, // Top right
-	    {1.0f, 0.0f, heroTexNDC.z, heroTexNDC.w}, // Bottom right
-	};
-
 	/* Create buffers */
 	glGenVertexArrays(1, &renderer->vao);
 	glGenBuffers(1, &renderer->vbo);
@@ -89,14 +95,9 @@ void worldTraveller_gameInit(GameState *state)
 	glBindBuffer(GL_ARRAY_BUFFER, renderer->vbo);
 	glBindVertexArray(renderer->vao);
 
-	/* Configure VBO */
-	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
-	glCheckError();
-
 	/* Configure VAO */
 	const GLuint numVertexElements = 4;
 	const GLuint vertexSize        = sizeof(v4);
-
 	glEnableVertexAttribArray(0);
 	glVertexAttribPointer(0, numVertexElements, GL_FLOAT, GL_FALSE, vertexSize,
 	                      (GLvoid *)0);
@@ -122,6 +123,7 @@ INTERNAL void parseInput(GameState *state, const f32 dt)
 	   f (t) = (a/2)*t^2 + v*t + p, where p is a constant, old position
 	 */
 
+	Entity *hero = &state->entityList[state->heroIndex];
 	v2 ddPos = V2(0, 0);
 
 	if (state->keys[GLFW_KEY_SPACE])
@@ -131,12 +133,12 @@ INTERNAL void parseInput(GameState *state, const f32 dt)
 	if (state->keys[GLFW_KEY_RIGHT])
 	{
 		ddPos.x = 1.0f;
-		state->heroLastDirection = direction_east;
+		hero->direction = direction_east;
 	}
 	if (state->keys[GLFW_KEY_LEFT])
 	{
 		ddPos.x = -1.0f;
-		state->heroLastDirection = direction_west;
+		hero->direction = direction_west;
 	}
 
 	if (state->keys[GLFW_KEY_UP])
@@ -164,7 +166,6 @@ INTERNAL void parseInput(GameState *state, const f32 dt)
 	ddPos = v2_scale(ddPos, heroSpeed);
 
 	// TODO(doyle): Counteracting force on player's acceleration is arbitrary
-	Entity *hero = &state->hero;
     ddPos = v2_sub(ddPos, v2_scale(hero->dPos, 5.5f));
 
 	/*
@@ -188,60 +189,38 @@ void worldTraveller_gameUpdateAndRender(GameState *state, const f32 dt)
 	parseInput(state, dt);
 	glCheckError();
 
-	Entity *hero       = &state->hero;
+	// NOTE(doyle): Factor to normalise sprite sheet rect coords to -1, 1
-	Texture *heroSheet = hero->tex;
+	Entity *hero  = &state->entityList[state->heroIndex];
-	f32 ndcFactor      = CAST(f32)heroSheet->width;
+	f32 ndcFactor = 1.0f / CAST(f32) hero->tex->width;
 
-	v2 heroStartPixel = V2(746.0f, 1018.0f); // direction == east
+	ASSERT(state->freeEntityIndex < ARRAY_COUNT(state->entityList));
+	for (i32 i = 0; i < state->freeEntityIndex; i++)
+	{
+		Entity *entity   = &state->entityList[i];
+		SpriteAnim *anim = &entity->anim;
 
-	v2 heroSizeOnSheet = V2(58.0f, 98.0f);
+		v4 currFrameRect = anim->rect[anim->currRectIndex];
-	v4 heroRect = V4(heroStartPixel.x,
+		anim->currDuration -= dt;
-	                 heroStartPixel.y,
+		if (anim->currDuration <= 0.0f)
-	                 heroStartPixel.x + heroSizeOnSheet.w,
+		{
-	                 heroStartPixel.y - heroSizeOnSheet.h);
+			anim->currRectIndex++;
+			anim->currRectIndex = anim->currRectIndex % anim->numRects;
+			currFrameRect         = anim->rect[anim->currRectIndex];
+			anim->currDuration  = anim->duration;
+		}
 
-	v4 heroTexNDC = v4_scale(heroRect, 1.0f / ndcFactor);
+		v4 texNDC = v4_scale(currFrameRect, ndcFactor);
-	if (state->heroLastDirection == direction_east)
+		if (entity->direction == direction_east)
 		{
 			// NOTE(doyle): Flip the x coordinates to flip the tex
-		v4 copyNDC = heroTexNDC;
+			v4 tmpNDC = texNDC;
-		heroTexNDC.x = copyNDC.z;
+			texNDC.x  = tmpNDC.z;
-		heroTexNDC.z = copyNDC.x;
+			texNDC.z  = tmpNDC.x;
 		}
 
-	updateBufferObject(state->renderer.vbo, heroTexNDC);
+		updateBufferObject(state->renderer.vbo, texNDC);
-	renderer_entity(&state->renderer, hero, 0.0f, V3(0, 0, 0));
+		renderer_entity(&state->renderer, entity, 0.0f, V3(0, 0, 0));
-
-	Entity npcEnt = {V2(300.0f, 300.0f), V2(0.0f, 0.0f), hero->size, hero->tex};
-
-	v4 npcRects[2] = {
-		{944.0f, 918.0f, 1010.0f, 816.0f},
-		{944.0f, 812.0f, 1010.0f, 710.0f},
-	};
-
-	LOCAL_PERSIST f32 frameDurationInSec = 0.0f;
-	LOCAL_PERSIST i32 npcLastRect        = 0;
-
-	frameDurationInSec -= dt;
-	v4 npcCurrRect = npcRects[npcLastRect];
-	if (frameDurationInSec <= 0.0f)
-	{
-		if (npcLastRect == 0)
-		{
-			npcCurrRect = npcRects[1];
-			npcLastRect = 1;
 	}
-		else
-		{
-			npcCurrRect = npcRects[0];
-			npcLastRect = 0;
-		}
-		frameDurationInSec = 0.3f;
-	}
-
-	v4 npcTexNDC = v4_scale(npcCurrRect, 1.0f / ndcFactor);
-	updateBufferObject(state->renderer.vbo, npcTexNDC);
-	renderer_entity(&state->renderer, &npcEnt, 0.0f, V3(0, 0, 0));
 
 	// TODO(doyle): Clean up lines
 	// Renderer::~Renderer() { glDeleteVertexArrays(1, &this->quadVAO); }

src/include/Dengine/Common.h

@@ -22,5 +22,7 @@ typedef double f64;
 
 #define ARRAY_COUNT(array) (sizeof(array) / sizeof(array[0]))
 #define CAST(type) (type)
+#define ASSERT(expr) if(!(expr)) { *(int *)0 = 0; }
+
 
 #endif

src/include/Dengine/Entity.h

@@ -4,12 +4,34 @@
 #include <Dengine/Texture.h>
 #include <Dengine/Math.h>
 
+enum Direction
+{
+	direction_north,
+	direction_west,
+	direction_south,
+	direction_east,
+	direction_num,
+	direction_null,
+};
+
+typedef struct SpriteAnim
+{
+	v4 *rect;
+	i32 numRects;
+	i32 currRectIndex;
+
+	f32 duration;
+	f32 currDuration;
+} SpriteAnim;
+
 typedef struct Entity
 {
 	v2 pos;  // Position
 	v2 dPos; // Velocity
 	v2 size;
+	enum Direction direction;
 	Texture *tex;
+	SpriteAnim anim;
 } Entity;
 
 #endif

src/include/WorldTraveller/WorldTraveller.h

@@ -15,15 +15,6 @@ enum State
 	state_win
 };
 
-enum Direction
-{
-	direction_north,
-	direction_west,
-	direction_south,
-	direction_east,
-	direction_num,
-};
-
 typedef struct GameState
 {
 	enum State state;
@@ -31,8 +22,11 @@ typedef struct GameState
 	i32 width, height;
 
 	Renderer renderer;
-	Entity hero;
+	i32 heroIndex;
-	enum Direction heroLastDirection;
+
+	// TODO(doyle): Make size of list dynamic
+	Entity entityList[256];
+	i32 freeEntityIndex;
 } GameState;
 
 void worldTraveller_gameInit(GameState *state);