Add arbitrary asteroid polygon rendering

src/Asteroid.c

@@ -163,10 +163,146 @@ INTERNAL b32 getKeyStatus(KeyState *key, enum ReadKeyType readType,
 	return FALSE;
 }
 
+typedef struct Basis
+{
+	v2 basis;
+	v2 pivotPoint;
+} Basis;
 
+enum RectBaseline
+{
+	rectbaseline_top,
+	rectbaseline_topLeft,
+	rectbaseline_topRight,
+	rectbaseline_bottom,
+	rectbaseline_bottomRight,
+	rectbaseline_bottomLeft,
+	rectbaseline_left,
+	rectbaseline_right,
+	rectbaseline_center,
+	rectbaseline_count,
+
+};
+
+Basis getBasis(Entity *entity, enum RectBaseline baseline)
+{
+	ASSERT(baseline < rectbaseline_count);
+
+	v2 basis = v2_sub(entity->pos, entity->offset);
+	v2 pivotPoint = v2_scale(entity->size, 0.5f);
+	v2 size = entity->size;
+	switch (baseline)
+	{
+		case rectbaseline_top:
+			basis.y += (size.h);
+			basis.x += (size.w * 0.5f);
+		    break;
+		case rectbaseline_topLeft:
+			basis.y += (size.h);
+		    break;
+		case rectbaseline_topRight:
+		    basis.y += (size.h);
+		    basis.x += (size.w);
+		    break;
+		case rectbaseline_bottom:
+			basis.x += (size.w * 0.5f);
+			break;
+		case rectbaseline_bottomRight:
+			basis.x += (size.w);
+			break;
+		case rectbaseline_left:
+			basis.y += (size.h * 0.5f);
+			break;
+		case rectbaseline_right:
+			basis.x += (size.w);
+			basis.y += (size.h * 0.5f);
+			break;
+
+		case rectbaseline_bottomLeft:
+		    break;
+		default:
+		    DEBUG_LOG(
+		        "getPosRelativeToRect() warning: baseline enum not recognised");
+			break;
+	}
+
+	Basis result      = {0};
+	result.basis      = basis;
+	result.pivotPoint = pivotPoint;
+
+	return result;
+}
+
+Basis getDefaultBasis(Entity *entity)
+{
+	Basis result = getBasis(entity, rectbaseline_bottomLeft);
+	return result;
+}
+
+#include <stdlib.h>
+#include <time.h>
+v2 *createAsteroidVertexList(MemoryArena_ *arena, v2 pos, i32 iterations)
+{
+	f32 iterationAngle = 360.0f / iterations;
+	iterationAngle     = DEGREES_TO_RADIANS(iterationAngle);
+	v2 *result =
+	    memory_pushBytes(arena, iterations * sizeof(v2));
+
+	srand(time(NULL));
+	for (i32 i = 0; i < iterations; i++)
+	{
+		i32 randValue      = rand();
+		i32 asteroidRadius = (randValue % 100) + 50;
+
+		result[i] = V2(math_cosf(iterationAngle * i) * asteroidRadius,
+		               math_sinf(iterationAngle * i) * asteroidRadius);
+		result[i] = v2_add(result[i], pos);
+
+#if 1
+		f32 displacementDist   = 0.25f * asteroidRadius;
+		i32 vertexDisplacement =
+		    randValue % (i32)displacementDist + (i32)(displacementDist * 0.1f);
+
+		i32 quadrantSize = iterations / 4;
+
+		i32 firstQuadrant  = quadrantSize;
+		i32 secondQuadrant = quadrantSize * 2;
+		i32 thirdQuadrant  = quadrantSize * 3;
+		i32 fourthQuadrant = quadrantSize * 4;
+
+		if (i < firstQuadrant)
+		{
+			result[i].x += vertexDisplacement;
+			result[i].y += vertexDisplacement;
+		}
+		else if (i < secondQuadrant)
+		{
+			result[i].x -= vertexDisplacement;
+			result[i].y += vertexDisplacement;
+		}
+		else if (i < thirdQuadrant)
+		{
+			result[i].x -= vertexDisplacement;
+			result[i].y -= vertexDisplacement;
+		}
+		else
+		{
+			result[i].x += vertexDisplacement;
+			result[i].y -= vertexDisplacement;
+		}
+#endif
+	}
+
+	return result;
+}
+
+LOCAL_PERSIST v2 *asteroidVertexList = NULL;
+LOCAL_PERSIST f32 updateAsteroidListTimerThreshold = 1.0f;
+LOCAL_PERSIST f32 updateAsteroidListTimer          = 1.0f;
 void asteroid_gameUpdateAndRender(GameState *state, Memory *memory,
                                   v2 windowSize, f32 dt)
 {
+	i32 iterations = 16;
 	if (!state->init)
 	{
 
@@ -200,11 +336,22 @@ void asteroid_gameUpdateAndRender(GameState *state, Memory *memory,
 
 		debug_init(&state->persistentArena, windowSize,
 		           state->assetManager.font);
+
+		asteroidVertexList =
+		    createAsteroidVertexList(&state->persistentArena, V2(500, 500), 16);
 	}
 
 	memory_arenaInit(&state->transientArena, memory->transient,
 	                 memory->transientSize);
 
+	updateAsteroidListTimer -= dt;
+	if (updateAsteroidListTimer < 0)
+	{
+		asteroidVertexList = createAsteroidVertexList(&state->persistentArena,
+		                                              V2(500, 500), iterations);
+		updateAsteroidListTimer = updateAsteroidListTimerThreshold;
+	}
+
 	{
 		KeyState *keys = state->input.keys;
 		for (enum KeyCode code = 0; code < keycode_count; code++)
@@ -236,8 +383,20 @@ void asteroid_gameUpdateAndRender(GameState *state, Memory *memory,
 		ASSERT(entity->type != entitytype_invalid);
 
 		v2 pivotPoint = {0};
-		if (entity->type == entitytype_ship) {
 
+		// Loop entity around world
+		if (entity->pos.y >= state->worldSize.h)
+			entity->pos.y = 0;
+		else if (entity->pos.y < 0)
+			entity->pos.y = state->worldSize.h;
+
+		if (entity->pos.x >= state->worldSize.w)
+			entity->pos.x = 0;
+		else if (entity->pos.x < 0)
+			entity->pos.x = state->worldSize.w;
+
+		if (entity->type == entitytype_ship)
+		{
 			v2 ddP = {0};
 			if (getKeyStatus(&state->input.keys[keycode_up], readkeytype_repeat,
 			                 0.0f, dt))
@@ -245,7 +404,9 @@ void asteroid_gameUpdateAndRender(GameState *state, Memory *memory,
 				// TODO(doyle): Renderer creates upfacing triangles by default,
 				// but we need to offset rotation so that our base "0 degrees"
 				// is right facing for trig to work
-				Radians rotation = DEGREES_TO_RADIANS((entity->rotation + 90.0f));
+				Radians rotation =
+				    DEGREES_TO_RADIANS((entity->rotation + 90.0f));
+
 				v2 direction = V2(math_cosf(rotation), math_sinf(rotation));
 				ddP          = direction;
 			}
@@ -293,25 +454,6 @@ void asteroid_gameUpdateAndRender(GameState *state, Memory *memory,
 			entity->pos = v2_add(v2_add(ddPHalfDtSquared, oldDpDt), oldPos);
 
 			pivotPoint = v2_scale(entity->size, 0.5f);
-		}
-
-		if (entity->pos.y >= state->worldSize.h)
-		{
-			entity->pos.y = 0;
-		}
-		else if (entity->pos.y < 0)
-		{
-			entity->pos.y = state->worldSize.h;
-		}
-
-		if (entity->pos.x >= state->worldSize.w)
-		{
-			entity->pos.x = 0;
-		}
-		else if (entity->pos.x < 0)
-		{
-			entity->pos.x = state->worldSize.w;
-		}
 
 			DEBUG_PUSH_VAR("Pos: %5.2f, %5.2f", entity->pos, "v2");
 			DEBUG_PUSH_VAR("Velocity: %5.2f, %5.2f", entity->dP, "v2");
@@ -321,18 +463,17 @@ void asteroid_gameUpdateAndRender(GameState *state, Memory *memory,
 			renderer_entity(&state->renderer, state->camera, entity, pivotPoint, 0,
 					V4(0.4f, 0.8f, 1.0f, 1.0f), flags);
 
-		v2 leftAlignedP = v2_sub(entity->pos, entity->offset);
+			Basis entityBasis = getDefaultBasis(entity);
-		renderer_rect(&state->renderer, state->camera, leftAlignedP,
+			renderer_rect(&state->renderer, state->camera, entityBasis.basis,
-		              entity->size, v2_scale(entity->size, 0.5f),
+					V2(4, 4), entityBasis.pivotPoint,
 					DEGREES_TO_RADIANS(entity->rotation), NULL,
-		              V4(1.0f, 0.8f, 1.0f, 1.0f), flags);
+					V4(1.0f, 0, 0, 1.0f), flags);
-
-		v2 rightAlignedP = v2_add(leftAlignedP, entity->size);
-		renderer_rect(&state->renderer, state->camera, rightAlignedP, V2(4, 4),
-		              v2_scale(pivotPoint, -1.0f),
-		              DEGREES_TO_RADIANS(entity->rotation), NULL,
-		              V4(0.4f, 0.8f, 1.0f, 1.0f), flags);
 		}
+	}
+
+	renderer_polygon(&state->renderer, &state->transientArena, state->camera,
+	                 asteroidVertexList, iterations, V2(0, 0), 0, NULL,
+	                 V4(0.0f, 0.0f, 1.0f, 1.0f), 0);
 
 	TrianglePoints triangle = {0};
 	triangle.points[0] = V2(100, 200);

src/Renderer.c

@@ -376,6 +376,52 @@ void renderer_rect(Renderer *const renderer, Rect camera, v2 pos, v2 size,
 		                       ARRAY_COUNT(vertexList), rendermode_quad, flags);
 }
 
+void renderer_polygon(Renderer *const renderer, MemoryArena_ *arena, Rect camera,
+                      v2 *polygonPoints, i32 numPoints, v2 pivotPoint,
+                      Radians rotate, RenderTex *renderTex, v4 color,
+                      RenderFlags flags)
+{
+	ASSERT(numPoints > 3);
+
+	for (i32 i = 0; i < numPoints; i++)
+		polygonPoints[i] = v2_sub(polygonPoints[i], camera.min);
+
+	RenderTex emptyRenderTex  = {0};
+	if (!renderTex) renderTex = &emptyRenderTex;
+
+	i32 numTrisInTriangulation = numPoints - 2;
+	RenderTriangle_ *polygonTriangulation = memory_pushBytes(
+	    arena, (sizeof(RenderTriangle_) * numTrisInTriangulation));
+
+	v2 triangulationBaseP = polygonPoints[0];
+	i32 triangulationIndex = 0;
+
+	Vertex triangulationBaseVertex = {0};
+	triangulationBaseVertex.pos = triangulationBaseP;
+
+	addVertexToRenderGroup(renderer, renderTex->tex, color,
+	                       &triangulationBaseVertex, 1, rendermode_polygon,
+	                       flags);
+	for (i32 i = 1; triangulationIndex < numTrisInTriangulation; i++)
+	{
+		RenderTriangle_ *tri = &polygonTriangulation[triangulationIndex++];
+		tri->vertex[0].pos = triangulationBaseP;
+		tri->vertex[1].pos = polygonPoints[i + 1];
+		tri->vertex[2].pos = polygonPoints[i];
+
+		addVertexToRenderGroup(renderer, renderTex->tex, color, tri->vertex, 3,
+		                       rendermode_polygon, flags);
+	}
+	RenderTriangle_ tri = polygonTriangulation[numTrisInTriangulation-1];
+	addVertexToRenderGroup(renderer, renderTex->tex, color, &tri.vertex[2], 1,
+	                       rendermode_polygon, flags);
+	/*
+	// NOTE(doyle): Create degenerate vertex setup
+	Vertex triVertexList[5] = {tri->vertex[0], tri->vertex[0], tri->vertex[1],
+	                           tri->vertex[2], tri->vertex[2]};
+	*/
+}
+
 void renderer_triangle(Renderer *const renderer, Rect camera,
                        TrianglePoints triangle, v2 pivotPoint, Radians rotate,
                        RenderTex *renderTex, v4 color, RenderFlags flags)
@@ -472,6 +518,7 @@ void renderer_string(Renderer *const renderer, MemoryArena_ *arena, Rect camera,
 void renderer_entity(Renderer *renderer, Rect camera, Entity *entity,
                      v2 pivotPoint, Degrees rotate, v4 color, RenderFlags flags)
 {
+	// TODO(doyle): Add early exit on entities out of camera bounds
 	Radians totalRotation = DEGREES_TO_RADIANS((entity->rotation + rotate));
 	RenderTex renderTex   = {0};
 	if (entity->tex)

src/include/Dengine/Renderer.h

@@ -35,10 +35,14 @@ enum RenderFlag {
 	renderflag_no_texture = 0x2,
 };
 
+// TODO(doyle): Since all vertexes are built with degenerate vertices and
+// in a triangle strip format, we should not split render groups by render mode
+// nor either generate buffers vao/vbo based on rendermode count
 enum RenderMode
 {
 	rendermode_quad,
 	rendermode_triangle,
+	rendermode_polygon,
 	rendermode_count,
 	rendermode_invalid,
 };
@@ -48,7 +52,6 @@ typedef struct RenderGroup
 	b32 init;
 	RenderFlags flags;
 	enum RenderMode mode;
-	u32 glRenderMode;
 
 	Texture *tex;
 	v4 color;
@@ -82,12 +85,18 @@ renderer_createNullRenderTex(AssetManager *const assetManager);
 // TODO(doyle): Clean up lines
 // Renderer::~Renderer() { glDeleteVertexArrays(1, &this->quadVAO); }
 void renderer_rect(Renderer *const renderer, Rect camera, v2 pos, v2 size,
-                   v2 pivotPoint, Radians rotate, RenderTex *renderTex, v4 color,
+                   v2 pivotPoint, Radians rotate, RenderTex *renderTex,
-                   RenderFlags flags);
+                   v4 color, RenderFlags flags);
+
+void renderer_polygon(Renderer *const renderer, MemoryArena_ *arena,
+                      Rect camera, v2 *polygonPoints, i32 numPoints,
+                      v2 pivotPoint, Radians rotate, RenderTex *renderTex,
+                      v4 color, RenderFlags flags);
 
 inline void renderer_staticRect(Renderer *const renderer, v2 pos, v2 size,
-                                v2 pivotPoint, Radians rotate, RenderTex *renderTex,
+                                v2 pivotPoint, Radians rotate,
-                                v4 color, RenderFlags flags)
+                                RenderTex *renderTex, v4 color,
+                                RenderFlags flags)
 {
 	Rect staticCamera = {V2(0, 0), renderer->size};
 	renderer_rect(renderer, staticCamera, pos, size, pivotPoint, rotate,
@@ -98,15 +107,15 @@ void renderer_triangle(Renderer *const renderer, Rect camera,
                        TrianglePoints triangle, v2 pivotPoint, Radians rotate,
                        RenderTex *renderTex, v4 color, RenderFlags flags);
 
-void renderer_string(Renderer *const renderer, MemoryArena_ *arena,
+void renderer_string(Renderer *const renderer, MemoryArena_ *arena, Rect camera,
-                     Rect camera, Font *const font,
+                     Font *const font, const char *const string, v2 pos,
-                     const char *const string, v2 pos, v2 pivotPoint,
+                     v2 pivotPoint, Radians rotate, v4 color,
-                     Radians rotate, v4 color, RenderFlags flags);
+                     RenderFlags flags);
 
 inline void renderer_staticString(Renderer *const renderer, MemoryArena_ *arena,
                                   Font *const font, const char *const string,
-                                  v2 pos, v2 pivotPoint, Radians rotate, v4 color,
+                                  v2 pos, v2 pivotPoint, Radians rotate,
-                                  RenderFlags flags)
+                                  v4 color, RenderFlags flags)
 {
 	Rect staticCamera = {V2(0, 0), renderer->size};
 	renderer_string(renderer, arena, staticCamera, font, string, pos,