re-implement updating satellite position

ext/tangerine

@@ -1 +1 @@
-Subproject commit c3d585201dbd134a833afb6c29d71c8d835a3192
+Subproject commit 77fd7c695789d621ea04471c6f0aaac01fa0e369

src/main.cpp

@@ -4,6 +4,7 @@
 
 #include <SDL2/SDL.h>
 #include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
 
 #include "input.h"
 #include "tangerine.h"
@@ -32,11 +33,6 @@ initEllipseEntity(RenderState* rs,
 	const ellipse_parameters& ep,
 	u32 num_vertices)
 {
-	ShaderProgram* shader = getShaderByName("colored_vertices", rs->gl_ctx);
-	RenderGroup* rg = getFreeRenderGroup(rs);
-	assert(shader && rg);
-	initRenderGroup(rg, rs->rg_arena, shader, 16, "ellipse_rg");
-
 	g_sys.e3d = ellipseInit3D(g_sys.ep, num_vertices);
 	Mesh* m = meshInit(rs->rg_arena, num_vertices, num_vertices, false, true);
 	vec3 vertex_color = vec3(255, 0, 255);
@@ -47,54 +43,79 @@ initEllipseEntity(RenderState* rs,
 		m->indices[i] = i;
 	}
 
-	u32 num_meshes = 1;
-	Model* mdl = modelInitManual(rs->rg_arena, num_meshes, m);
+	Model* mdl = modelInitManual(rs->rg_arena, 1, m);
+	RenderGroup* rg = getRenderGroupByName(rs, "manual mesh group");
 	Entity* e = getFreeEntity(rg);
 	initEntity(e, rs->gl_ctx,
 				rs->rg_arena,
 				mdl,
-				shader->num_vertex_attribs,
-				shader->attrib_mappings,
+				rg->shader->num_vertex_attribs,
+				rg->shader->attrib_mappings,
 				"ellipse 01",
 				GL_LINE_LOOP);
 
 	return e;
 }
 
-Mesh*
-constructCircleMesh(float r, uint vert_count, glm::vec3 vertex_color)
+Entity*
+initPlanetEntity(RenderState* rs)
 {
-#if 0
-	simple_mesh* sm = meInitMesh(vert_count);
-	float angle = (float) M_PI * 2 / vert_count;
-	r = r / SCALING;
+	u32 num_vertices = 24;
+	vec3 vertex_color = vec3(255, 255, 0);
+	float radius = 3;
+
+	Mesh* m = meshInit(rs->rg_arena, num_vertices, num_vertices, false, true);
+	float angle = (float) M_PI * 2 / num_vertices;
+	float r = radius / SCALING;
 
-	for (uint i = 0; i < vert_count; i++) {
-		sm->vertices[i] = glm::vec3(cos(i * angle) * r, sin(i * angle) * r, 0);
-		sm->vert_colors[i] = vertex_color;
+	for (uint i = 0; i < num_vertices; i++) {
+		m->vertices[i] = glm::vec3(cos(i * angle) * r, sin(i * angle) * r, 0);
+		m->colors[i] = vertex_color;
+		m->indices[i] = i;
 	}
 
-	return sm;
-#endif
-	return nullptr;
+	Model* mdl = modelInitManual(rs->rg_arena, 1, m);
+	RenderGroup* rg = getRenderGroupByName(rs, "manual mesh group");
+	Entity* e = getFreeEntity(rg);
+	initEntity(e, rs->gl_ctx,
+				rs->rg_arena,
+				mdl,
+				rg->shader->num_vertex_attribs,
+				rg->shader->attrib_mappings,
+				"planet 01",
+				GL_LINE_LOOP);
+
+	return e;
 }
 
-Mesh*
-createSatelliteMesh()
+Entity*
+initSatelliteEntity(RenderState* rs)
 {
-#if 0
-	simple_mesh* sm = meInitMesh(3);
-	glm::vec3 s_color(255, 0, 0);
-	sm->vertices[0] = glm::vec3(0, 1 / SCALING, 0);
-	sm->vert_colors[0] = s_color;
-	sm->vertices[1] = glm::vec3(-1 / SCALING, -1 / SCALING, 0);
-	sm->vert_colors[1] = s_color;
-	sm->vertices[2] = glm::vec3(1 / SCALING, -1 / SCALING, 0);
-	sm->vert_colors[2] = s_color;
-
-	return sm;
-#endif
-	return nullptr;
+	u32 num_vertices = 3;
+	vec3 vertex_color = vec3(255, 0, 0);
+	Mesh* m = meshInit(rs->rg_arena, num_vertices, num_vertices, false, true);
+	m->vertices[0] = vec3(0, 1, 0);
+	m->colors[0] = vertex_color;
+	m->indices[0] = 0;
+	m->vertices[1] = vec3(-1, -1, 0);
+	m->colors[1] = vertex_color;
+	m->indices[1] = 1;
+	m->vertices[2] = vec3(1, -1, 0);
+	m->colors[2] = vertex_color;
+	m->indices[2] = 2;
+
+	Model* mdl = modelInitManual(rs->rg_arena, 1, m);
+	RenderGroup* rg = getRenderGroupByName(rs, "manual mesh group");
+	Entity* e = getFreeEntity(rg);
+	initEntity(e, rs->gl_ctx,
+				rs->rg_arena,
+				mdl,
+				rg->shader->num_vertex_attribs,
+				rg->shader->attrib_mappings,
+				"ship 01",
+				GL_TRIANGLES);
+
+	return e;
 }
 
 void
@@ -108,22 +129,23 @@ loadScene(RenderState* rs)
 	double r = 6378;		// NOTE: body radius in km
 	g_sys = systemInit(gravBodyInit(mu, r), orbitInit(a, e));
 
+	// TODO: streamline the boilerplate in init_X_Entity functions
 	g_arena = arenaInit(16);
+	ShaderProgram* shader = getShaderByName("colored_vertices", rs->gl_ctx);
+	initRenderGroup(
+		getFreeRenderGroup(rs), rs->rg_arena, shader, 256, "manual mesh group");
+
 	Entity* ellipse_entity = initEllipseEntity(rs, g_sys.ep, 256);
 	setEntityPosition(ellipse_entity, vec3(0, 0, 0));
 	rotateEntity(ellipse_entity, vec3(1, 0, 0), (float) M_PI / 2);
-#if 0
-	entity& planet_entity = rs->render_groups[0].entities[1];
-	sm = constructCircleMesh(3, 24, glm::vec3(255, 255, 0));
-	entInitMesh(planet_entity, sm, GL_LINE_LOOP);
-	entRotate(planet_entity, (float) M_PI_2, glm::vec3(1, 0, 0));
-
-	entity& satellite_entity = rs->render_groups[0].entities[2];
-	sm = createSatelliteMesh();
-	entInitMesh(satellite_entity, sm, GL_TRIANGLES);
-	entRotate(satellite_entity, (float) M_PI_2, glm::vec3(1, 0, 0));
-	entSetWorldPosition(satellite_entity, g_sys.e3d.vertices[0]);
-#endif
+
+	Entity* planet_entity = initPlanetEntity(rs);
+	rotateEntity(planet_entity, vec3(1, 0, 0), (float) M_PI / 2);
+
+	Entity* satellite_entity = initSatelliteEntity(rs);
+	scaleEntity(satellite_entity, 1 / SCALING);
+	rotateEntity(satellite_entity, vec3(1, 0, 0), (float) M_PI / 2);
+	setEntityPosition(satellite_entity, g_sys.e3d.vertices[0]);
 }
 
 void
@@ -137,15 +159,13 @@ updateSatelliteModel(const system_2body& sys, satellite& sat)
 }
 
 void
-updateSatelliteEntity(Entity& ent, const satellite& sat)
+updateSatelliteEntity(Entity* e, const satellite& sat)
 {
-#if 0
 	// TODO: decouple framerate from time_step
-	const static glm::mat4 xform =
-		glm::rotate(glm::mat4(1.0), (float) M_PI_2, glm::vec3(1, 0, 0));
-	const glm::vec3& v = sat.position;
-	entSetWorldPosition(ent, xform * glm::vec4(v.x, v.y, v.z, 1));
-#endif
+	const static mat4 xform =
+		glm::rotate(mat4(1.0), (float) M_PI_2, vec3(1, 0, 0));
+	const vec3& v = sat.position;
+	setEntityPosition(e, xform * vec4(v.x, v.y, v.z, 1));
 }
 
 // NOTE: use ellipseValidate(ep) before calling to avoid failing assertions
@@ -183,12 +203,18 @@ postFrameCallback(RenderState* rs)
 {
 	gooDraw(rs->handles.window, g_sys);
 	g_sys.ep = ellipseInitAE(g_sys.ep.a, g_sys.ep.e);
-#if 0
-	entity& ellipse_entity = rs->render_groups[0].entities[0];
-	updateOrbit(g_sys, ellipse_entity);
 	updateSatelliteModel(g_sys, g_sys.sat);
-	updateSatelliteEntity(rs->render_groups[0].entities[2], g_sys.sat);
-#endif
+
+	static Entity* satellite = nullptr;
+
+	if (satellite == nullptr) {
+		RenderGroup* rg = getRenderGroupByName(rs, "manual mesh group");
+		satellite = getEntityByName(rg, "ship 01");
+	}
+
+	assert(satellite);
+	updateSatelliteEntity(satellite, g_sys.sat);
+	//updateOrbit(g_sys, ellipse_entity);
 }
 
 int