libTangerine/examples/simple_mesh/main.cpp

#include <glm/glm.hpp>

#include "dumbLog.h"
#include "input.h"
#include "mesh.h"
#include "renderer.h"


void
doFrameCallbackPre(render_state* rs)
{
	static input_state is = {};
	inputProcessEvents(&is);

	if (is.window_closed || is.escape) {
		rs->running = false;
		return;
	}

	int rotate_mod = 0;

	if (is.left)
		rotate_mod = -1;
	if (is.right)
		rotate_mod = 1;

	// NOTE: rotate mesh on z-axis every frame
	entity& e = rs->render_groups[0].entities[0];
	static float angle = (float) M_PI_2 / 33;
	static glm::vec3 axis(0, 0, 1);
	entRotate(e, angle * rotate_mod, axis);
}

simple_mesh*
makeSquareMesh()
{
	uint num_vertices = 4;
	simple_mesh* sm = meInitMesh(num_vertices);
	sm->num_vertices = num_vertices;

	sm->vertices[0] = glm::vec3(-200, 0, 200);
	sm->vertices[1] = glm::vec3(-200, 0, -200);
	sm->vertices[2] = glm::vec3(200, 0, -200);
	sm->vertices[3] = glm::vec3(200, 0, 200);
	sm->vert_colors[0] = glm::vec3(255, 0, 0);
	sm->vert_colors[1] = glm::vec3(255, 0, 0);
	sm->vert_colors[2] = glm::vec3(255, 0, 0);
	sm->vert_colors[3] = glm::vec3(255, 0, 0);

	return sm;
}

int
main()
{
	render_state* rs = renInit("simple mesh");

	if (rs == nullptr) {
		LOG(Error) << "Error Initialzing renderer\n";
		return 1;
	}

	// TODO: this needs to be more convenient
	shader_wrapper sw = { SIMPLE_SHADER, nullptr, rs->simple_shader };
	rs->render_groups = renAllocateGroup(1, sw);
	rs->render_group_count = 1;

	entity& e = rs->render_groups[0].entities[0];
	simple_mesh* sm = makeSquareMesh();

	// TODO: better usage would be: renPushEntity(rs->render_groups[0], e);
	// 	would need to allocate a reasonable block size by default (~64), and
	// 	double it if pushing to render_group would overflow
	entInitMesh(e, sm, GL_LINE_LOOP);

	cameraInitPerspective(
		rs->cam,
		glm::vec3(0, -500, 0),
		glm::vec3(0, 0, 0),
		glm::vec3(0,0,1)
	);

	renDoRenderLoop(rs, 60, doFrameCallbackPre);

	renShutdown(rs);
	return 0;
}