35-dynamic.lua

package.cpath = "bin/?.dll"

local iup = require "iuplua"
local bgfx = require "bgfx"
local util = require "util"
local math3d = require "math3d"

local kDimWidth  = 11
local kDimHeight = 11

local s_cubeVertices = {
	-1.0,  1.0,  1.0, 0xff000000 ,
	 1.0,  1.0,  1.0, 0xff0000ff ,
	-1.0, -1.0,  1.0, 0xff00ff00 ,
	 1.0, -1.0,  1.0, 0xff00ffff ,
	-1.0,  1.0, -1.0, 0xffff0000 ,
	 1.0,  1.0, -1.0, 0xffff00ff ,
	-1.0, -1.0, -1.0, 0xffffff00 ,
	 1.0, -1.0, -1.0, 0xffffffff ,
}

local ctx = {
	canvas = iup.canvas {},
}

local dlg = iup.dialog {
	ctx.canvas,
	title = "35-dynamic",
	size = "HALFxHALF",
}

local tmp = {}
local time = 0
local function mainloop()
	math3d.reset()
	bgfx.touch(0)
	time = time + 0.01

	do
		local angle = math.random()
		local mtx = math3d.matrix { r = { 0,0, angle } }
		for i = 1, 32, 4 do
			local vec = math3d.vector(s_cubeVertices[i], s_cubeVertices[i+1], s_cubeVertices[i+2])
			vec = math3d.totable(math3d.transform( mtx, vec, 1))
			tmp[i], tmp[i+1], tmp[i+2] = vec[1],vec[2],vec[3]
			local r = math.random(0,0xff)
			local g = math.random(0,0xff)
			local b = math.random(0,0xff)
			local a = math.random(0,0xff)
			tmp[i+3] = r << 24 | g << 16 | b << 8 | a
		end

		local idx = math.random(1, kDimWidth*kDimHeight)
		bgfx.update(ctx.m_vbh[idx], 0, bgfx.memory_buffer("fffd", tmp))
	end

	-- Submit 11x11 cubes.

	for yy = 0, kDimHeight do
		for xx = 0, kDimWidth do
			local mtx = math3d.matrix { r = {time + xx*0.21, time + yy * 0.37, 0}, t = {-15.0 + xx * 3, -15.0 + yy * 3, 0} }
			-- Set model matrix for rendering.
			bgfx.set_transform(mtx)
			-- Set vertex and index buffer.
			bgfx.set_vertex_buffer(ctx.m_vbh[yy*kDimWidth+xx+1])
			bgfx.set_index_buffer(ctx.m_ibh)
			-- Set render states.
			bgfx.set_state(ctx.state)
			-- Submit primitive for rendering to view 0.
			bgfx.submit(0, ctx.prog)
		end
	end

	bgfx.frame()
end

function ctx.init()
	bgfx.set_view_clear(0, "CD", 0x303030ff, 1, 0)

	ctx.vdecl = bgfx.vertex_layout {
		{ "POSITION", 3, "FLOAT" },
		{ "COLOR0", 4, "UINT8", true },
	}
	-- Create static vertex buffer.
	ctx.m_vbh = {}

	for yy = 0 , kDimHeight do
		for xx = 0, kDimWidth do
			ctx.m_vbh[yy*kDimWidth+xx+1] = bgfx.create_dynamic_vertex_buffer(
						bgfx.memory_buffer("fffd", s_cubeVertices), ctx.vdecl)
		end
	end

	-- Create static index buffer.
	ctx.m_ibh = bgfx.create_dynamic_index_buffer {
	0, 1, 2,
	3,
	7,
	1,
	5,
	0,
	4,
	2,
	6,
	7,
	4,
	5,
	}

	ctx.prog = util.programLoad("vs_cubes", "fs_cubes")

	ctx.state = bgfx.make_state({ PT = "TRISTRIP" } , nil)	-- base on BGFX_STATE_DEFAULT
end

function ctx.resize(w,h)
	ctx.width = w
	ctx.height = h
	bgfx.set_view_rect(0, 0, 0, ctx.width, ctx.height)
	bgfx.reset(ctx.width,ctx.height, "vmx")
	local viewmat = math3d.lookat ( { 0,0,-35}, { 0,0,0})
	local projmat = math3d.projmat { fov = 60, aspect = w/h, n = 0.1, f = 100 }
	bgfx.set_view_transform(0, viewmat, projmat)
end

util.init(ctx)
dlg:showxy(iup.CENTER,iup.CENTER)
dlg.usersize = nil
util.run(mainloop)