422 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			V
		
	
	
			
		
		
	
	
			422 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			V
		
	
	
/**********************************************************************
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*
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* Sokol 3d cube demo
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*
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* Copyright (c) 2021 Dario Deledda. All rights reserved.
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* Use of this source code is governed by an MIT license
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* that can be found in the LICENSE file.
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*
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* HOW TO COMPILE SHADERS:
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* - download the sokol shader convertor tool from https://github.com/floooh/sokol-tools-bin/archive/pre-feb2021-api-changes.tar.gz
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* ( also look at https://github.com/floooh/sokol-tools/blob/master/docs/sokol-shdc.md )
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* - compile the .glsl shader with:
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* linux  :  sokol-shdc --input rt_glsl.glsl --output rt_glsl.h --slang glsl330
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* windows:  sokol-shdc.exe --input rt_glsl.glsl --output rt_glsl.h --slang glsl330
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*
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* --slang parameter can be:
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* - glsl330: desktop GL
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* - glsl100: GLES2 / WebGL
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* - glsl300es: GLES3 / WebGL2
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* - hlsl4: D3D11
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* - hlsl5: D3D11
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* - metal_macos: Metal on macOS
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* - metal_ios: Metal on iOS device
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* - metal_sim: Metal on iOS simulator
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* - wgpu: WebGPU
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*
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* you can have multiple platforms at the same time passing parameters like this: --slang glsl330:hlsl5:metal_macos
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* for further infos have a look at the sokol shader tool docs.
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*
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* TODO:
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* - frame counter
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**********************************************************************/
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import gg
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import gg.m4
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import gx
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// import math
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import sokol.sapp
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import sokol.gfx
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import sokol.sgl
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import time
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// GLSL Include and functions
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#flag -I @VROOT/.
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#include "rt_glsl.h" #Please use sokol-shdc to generate the necessary rt_glsl.h file from rt_glsl.glsl (see the instructions at the top of this file)
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fn C.rt_shader_desc() &C.sg_shader_desc
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const (
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	win_width  = 800
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	win_height = 800
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	bg_color   = gx.white
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)
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struct App {
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mut:
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	gg          &gg.Context
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	texture     C.sg_image
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	init_flag   bool
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	frame_count int
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	mouse_x int = -1
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	mouse_y int = -1
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	// glsl
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	cube_pip_glsl C.sg_pipeline
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	cube_bind     C.sg_bindings
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	// time
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	ticks i64
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}
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/******************************************************************************
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* Texture functions
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******************************************************************************/
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fn create_texture(w int, h int, buf byteptr) C.sg_image {
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	sz := w * h * 4
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	mut img_desc := C.sg_image_desc{
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		width: w
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		height: h
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		num_mipmaps: 0
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		min_filter: .linear
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		mag_filter: .linear
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		// usage: .dynamic
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		wrap_u: .clamp_to_edge
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		wrap_v: .clamp_to_edge
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		label: &byte(0)
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		d3d11_texture: 0
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	}
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	// comment if .dynamic is enabled
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	img_desc.content.subimage[0][0] = C.sg_subimage_content{
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		ptr: buf
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		size: sz
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	}
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	sg_img := C.sg_make_image(&img_desc)
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	return sg_img
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}
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fn destroy_texture(sg_img C.sg_image) {
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	C.sg_destroy_image(sg_img)
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}
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// Use only if usage: .dynamic is enabled
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fn update_text_texture(sg_img C.sg_image, w int, h int, buf byteptr) {
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	sz := w * h * 4
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	mut tmp_sbc := C.sg_image_content{}
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	tmp_sbc.subimage[0][0] = C.sg_subimage_content{
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		ptr: buf
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		size: sz
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	}
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	C.sg_update_image(sg_img, &tmp_sbc)
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}
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/******************************************************************************
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* Draw functions
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******************************************************************************
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Cube vertex buffer with packed vertex formats for color and texture coords.
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		Note that a vertex format which must be portable across all
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		backends must only use the normalized integer formats
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		(BYTE4N, UBYTE4N, SHORT2N, SHORT4N), which can be converted
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		to floating point formats in the vertex shader inputs.
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		The reason is that D3D11 cannot convert from non-normalized
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		formats to floating point inputs (only to integer inputs),
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		and WebGL2 / GLES2 don't support integer vertex shader inputs.
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*/
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struct Vertex_t {
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	x     f32
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	y     f32
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	z     f32
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	color u32
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	u     f32
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	v     f32
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	// u u16   // for compatibility with D3D11
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	// v u16   // for compatibility with D3D11
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}
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fn init_cube_glsl(mut app App) {
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	// cube vertex buffer
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	// d := u16(32767)     // for compatibility with D3D11, 32767 stand for 1
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	d := f32(1.0)
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	c := u32(0xFFFFFF_FF) // color RGBA8
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	vertices := [
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		// Face 0
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		Vertex_t{-1.0, -1.0, -1.0, c,  0, 0},
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		Vertex_t{ 1.0, -1.0, -1.0, c,  d, 0},
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    Vertex_t{ 1.0,  1.0, -1.0, c,  d, d},
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    Vertex_t{-1.0,  1.0, -1.0, c,  0, d},
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		// Face 1
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		Vertex_t{-1.0, -1.0,  1.0, c,  0, 0},
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    Vertex_t{ 1.0, -1.0,  1.0, c,  d, 0},
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    Vertex_t{ 1.0,  1.0,  1.0, c,  d, d},
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    Vertex_t{-1.0,  1.0,  1.0, c,  0, d},
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		// Face 2
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		Vertex_t{-1.0, -1.0, -1.0, c,  0, 0},
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    Vertex_t{-1.0,  1.0, -1.0, c,  d, 0},
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    Vertex_t{-1.0,  1.0,  1.0, c,  d, d},
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    Vertex_t{-1.0, -1.0,  1.0, c,  0, d},
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		// Face 3
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		Vertex_t{ 1.0, -1.0, -1.0, c,  0, 0},
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    Vertex_t{ 1.0,  1.0, -1.0, c,  d, 0},
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    Vertex_t{ 1.0,  1.0,  1.0, c,  d, d},
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    Vertex_t{ 1.0, -1.0,  1.0, c,  0, d},
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		// Face 4
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		Vertex_t{-1.0, -1.0, -1.0, c,  0, 0},
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    Vertex_t{-1.0, -1.0,  1.0, c,  d, 0},
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    Vertex_t{ 1.0, -1.0,  1.0, c,  d, d},
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    Vertex_t{ 1.0, -1.0, -1.0, c,  0, d},
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		// Face 5
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		Vertex_t{-1.0,  1.0, -1.0, c,  0, 0},
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    Vertex_t{-1.0,  1.0,  1.0, c,  d, 0},
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    Vertex_t{ 1.0,  1.0,  1.0, c,  d, d},
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    Vertex_t{ 1.0,  1.0, -1.0, c,  0, d},
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	]
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	mut vert_buffer_desc := C.sg_buffer_desc{}
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	unsafe { C.memset(&vert_buffer_desc, 0, sizeof(vert_buffer_desc)) }
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	vert_buffer_desc.size = vertices.len * int(sizeof(Vertex_t))
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	vert_buffer_desc.content = byteptr(vertices.data)
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	vert_buffer_desc.@type = .vertexbuffer
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	vert_buffer_desc.label = 'cube-vertices'.str
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	vbuf := gfx.make_buffer(&vert_buffer_desc)
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	// create an index buffer for the cube
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	indices := [
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			u16(0),	1,	2,  	0, 	2, 	3,
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			6, 	5,	4,		7,	6,	4,
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			8,	9,	10,		8,	10,	11,
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			14,	13,	12,		15,	14,	12,
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			16,	17,	18,		16,	18,	19,
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			22,	21,	20,		23,	22,	20,
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	]
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	mut index_buffer_desc := C.sg_buffer_desc{}
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	unsafe {C.memset(&index_buffer_desc, 0, sizeof(index_buffer_desc))}
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	index_buffer_desc.size    = indices.len * int(sizeof(u16))
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	index_buffer_desc.content = byteptr(indices.data)
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	index_buffer_desc.@type   = .indexbuffer
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	index_buffer_desc.label   = "cube-indices".str
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	ibuf := gfx.make_buffer(&index_buffer_desc)
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	// create shader
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	shader := gfx.make_shader(C.rt_shader_desc())
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	mut pipdesc := C.sg_pipeline_desc{}
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	unsafe { C.memset(&pipdesc, 0, sizeof(pipdesc)) }
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	pipdesc.layout.buffers[0].stride = int(sizeof(Vertex_t))
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	// the constants [C.ATTR_vs_pos, C.ATTR_vs_color0, C.ATTR_vs_texcoord0] are generated by sokol-shdc
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	pipdesc.layout.attrs[C.ATTR_vs_pos      ].format = .float3  // x,y,z as f32
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	pipdesc.layout.attrs[C.ATTR_vs_color0   ].format = .ubyte4n // color as u32
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	pipdesc.layout.attrs[C.ATTR_vs_texcoord0].format = .float2  // u,v as f32
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	// pipdesc.layout.attrs[C.ATTR_vs_texcoord0].format  = .short2n  // u,v as u16
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	pipdesc.shader = shader
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	pipdesc.index_type = .uint16
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	pipdesc.depth_stencil = C.sg_depth_stencil_state{
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		depth_write_enabled: true
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		depth_compare_func: gfx.CompareFunc(C.SG_COMPAREFUNC_LESS_EQUAL)
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	}
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	pipdesc.rasterizer = C.sg_rasterizer_state{
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		cull_mode: .back
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	}
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	pipdesc.label = 'glsl_shader pipeline'.str
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	app.cube_bind.vertex_buffers[0] = vbuf
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	app.cube_bind.index_buffer = ibuf
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	app.cube_bind.fs_images[C.SLOT_tex] = app.texture
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	app.cube_pip_glsl = gfx.make_pipeline(&pipdesc)
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	println('GLSL init DONE!')
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}
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[inline] 
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fn vec4(x f32, y f32, z f32, w f32) m4.Vec4 {
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	return m4.Vec4{e:[x, y, z, w]!}
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}
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fn calc_tr_matrices(w f32, h f32, rx f32, ry f32, in_scale f32) m4.Mat4 {
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	proj := m4.perspective(60, w/h, 0.01, 10.0)
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	view := m4.look_at(vec4(f32(0.0) ,0 , 6, 0), vec4(f32(0), 0, 0, 0), vec4(f32(0), 1, 0, 0))
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	view_proj := view * proj
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	rxm := m4.rotate(m4.rad(rx), vec4(f32(1), 0, 0, 0))
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	rym := m4.rotate(m4.rad(ry), vec4(f32(0), 1, 0, 0))
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	model :=  rym * rxm
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	scale_m := m4.scale(vec4(in_scale, in_scale, in_scale, 1))
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	res :=  (scale_m * model) * view_proj
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	return res
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}
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fn draw_cube_glsl(app App) {
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	if app.init_flag == false {
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		return
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	}
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	ws := gg.window_size_real_pixels()
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	ratio := f32(ws.width) / ws.height
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	dw := f32(ws.width / 2)
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	dh := f32(ws.height / 2)
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	// use the following commented lines to rotate the 3d glsl cube
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	// rot := [f32(app.mouse_y), f32(app.mouse_x)]
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	// calc_tr_matrices(dw, dh, rot[0], rot[1] ,2.3)
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	tr_matrix := calc_tr_matrices(dw, dh, 0, 0, 2.3)
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	gfx.apply_viewport(0, 0, ws.width, ws.height, true)
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	// apply the pipline and bindings
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	gfx.apply_pipeline(app.cube_pip_glsl)
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	gfx.apply_bindings(app.cube_bind)
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	// Uniforms
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	// *** vertex shadeer uniforms ***
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	// passing the view matrix as uniform
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	// res is a 4x4 matrix of f32 thus: 4*16 byte of size
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	gfx.apply_uniforms(C.SG_SHADERSTAGE_VS, C.SLOT_vs_params, &tr_matrix, 4 * 16)
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	// *** fragment shader uniforms ***
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	time_ticks := f32(time.ticks() - app.ticks) / 1000
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	mut tmp_fs_params := [
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		f32(ws.width),
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		ws.height * ratio,           // x,y resolution to pass to FS
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		app.mouse_x,                 // mouse x
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		ws.height - app.mouse_y * 2, // mouse y scaled
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		time_ticks,                  // time as f32
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		app.frame_count,             // frame count
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		0,
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		0 // padding bytes , see "fs_params" struct paddings in rt_glsl.h 
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	]!
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	gfx.apply_uniforms(C.SG_SHADERSTAGE_FS, C.SLOT_fs_params, &tmp_fs_params, int(sizeof(tmp_fs_params)))
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	// 3 vertices for triangle * 2 triangles per face * 6 faces = 36 vertices to draw
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	gfx.draw(0, (3 * 2) * 6, 1)
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	gfx.end_pass()
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	gfx.commit()
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}
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fn frame(mut app App) {
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	ws := gg.window_size_real_pixels()
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	// clear
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	mut color_action := C.sg_color_attachment_action{
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		action: gfx.Action(C.SG_ACTION_CLEAR)
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	}
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	color_action.val[0] = 0
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	color_action.val[1] = 0
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	color_action.val[2] = 0
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	color_action.val[3] = 1.0
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	mut pass_action := C.sg_pass_action{}
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	pass_action.colors[0] = color_action
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	gfx.begin_default_pass(&pass_action, ws.width, ws.height)
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	// glsl cube
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	draw_cube_glsl(app)
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	app.frame_count++
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}
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/******************************************************************************
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* Init / Cleanup
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******************************************************************************/
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fn my_init(mut app App) {
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	// set max vertices,
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	// for a large number of the same type of object it is better use the instances!!
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	desc := sapp.create_desc()
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	gfx.setup(&desc)
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	sgl_desc := C.sgl_desc_t{
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		max_vertices: 50 * 65536
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	}
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	sgl.setup(&sgl_desc)
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	// create chessboard texture 256*256 RGBA
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	w := 256
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	h := 256
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	sz := w * h * 4
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	tmp_txt := unsafe { malloc(sz) }
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	mut i := 0
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	for i < sz {
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		unsafe {
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			y := (i >> 0x8) >> 5 // 8 cell
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			x := (i & 0xFF) >> 5 // 8 cell
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			// upper left corner
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			if x == 0 && y == 0 {
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				tmp_txt[i + 0] = byte(0xFF)
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				tmp_txt[i + 1] = byte(0)
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				tmp_txt[i + 2] = byte(0)
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				tmp_txt[i + 3] = byte(0xFF)
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			}
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			// low right corner
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			else if x == 7 && y == 7 {
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				tmp_txt[i + 0] = byte(0)
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				tmp_txt[i + 1] = byte(0xFF)
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				tmp_txt[i + 2] = byte(0)
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				tmp_txt[i + 3] = byte(0xFF)
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			} else {
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				col := if ((x + y) & 1) == 1 { 0xFF } else { 128 }
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				tmp_txt[i + 0] = byte(col)  // red
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				tmp_txt[i + 1] = byte(col)  // green
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				tmp_txt[i + 2] = byte(col)  // blue
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				tmp_txt[i + 3] = byte(0xFF) // alpha
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			}
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			i += 4
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		}
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	}
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	unsafe {
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		app.texture = create_texture(w, h, tmp_txt)
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		free(tmp_txt)
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	}
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	// glsl
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	init_cube_glsl(mut app)
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	app.init_flag = true
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}
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fn cleanup(mut app App) {
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	gfx.shutdown()
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}
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/******************************************************************************
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* events handling
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******************************************************************************/
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fn my_event_manager(mut ev gg.Event, mut app App) {
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	if ev.typ == .mouse_move {
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		app.mouse_x = int(ev.mouse_x)
 | 
						|
		app.mouse_y = int(ev.mouse_y)
 | 
						|
	}
 | 
						|
	if ev.typ == .touches_began || ev.typ == .touches_moved {
 | 
						|
		if ev.num_touches > 0 {
 | 
						|
			touch_point := ev.touches[0]
 | 
						|
			app.mouse_x = int(touch_point.pos_x)
 | 
						|
			app.mouse_y = int(touch_point.pos_y)
 | 
						|
		}
 | 
						|
	}
 | 
						|
}
 | 
						|
 | 
						|
/******************************************************************************
 | 
						|
* Main
 | 
						|
******************************************************************************/
 | 
						|
[console] // is needed for easier diagnostics on windows
 | 
						|
fn main() {
 | 
						|
	// App init
 | 
						|
	mut app := &App{
 | 
						|
		gg: 0
 | 
						|
	}
 | 
						|
 | 
						|
	app.gg = gg.new_context(
 | 
						|
		width: win_width
 | 
						|
		height: win_height
 | 
						|
		use_ortho: true // This is needed for 2D drawing
 | 
						|
		create_window: true
 | 
						|
		window_title: '3D Ray Marching Cube'
 | 
						|
		user_data: app
 | 
						|
		bg_color: bg_color
 | 
						|
		frame_fn: frame
 | 
						|
		init_fn: my_init
 | 
						|
		cleanup_fn: cleanup
 | 
						|
		event_fn: my_event_manager
 | 
						|
	)
 | 
						|
 | 
						|
	app.ticks = time.ticks()
 | 
						|
	app.gg.run()
 | 
						|
}
 |