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// Check if a tile is visible onscreen using it's MVP transform.
static inline bool MapTileFrustumCull(const mat4 mvp){
	// Clip space center and extents.
	vec4 c = {mvp.m[12], mvp.m[13], mvp.m[14], mvp.m[15]};
	vfloat ex = vabs(mvp.m[ 0]) + vabs(mvp.m[ 4]) + vabs(mvp.m[ 8]);
	vfloat ey = vabs(mvp.m[ 1]) + vabs(mvp.m[ 5]) + vabs(mvp.m[ 9]);
	vfloat ez = vabs(mvp.m[ 2]) + vabs(mvp.m[ 6]) + vabs(mvp.m[10]);
	
	// Check the bounds against the clip space viewport using a conservative w-value.
	vfloat w = vmax(0, c.w + vabs(mvp.m[ 3]) + vabs(mvp.m[ 7]) + vabs(mvp.m[11]));

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#include <stdbool.h>
#include <math.h>
#include <stdio.h>

#include <GL/gl.h>

// A vaguely SDL-like API
void iSDL_init(void);
bool iSDL_should_exit;
void iSDL_swap_buffers(void);

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double delta_time_filtered(double dt_nanos){
	// Warm start the filter by assuming 60 Hz.
	static double x[] = {1.6e7, 1.6e7, 1.6e7}, y[] = {1.6e7, 1.6e7, 1.6e7};
	// IIR filter coefficients. 2rd order lowpass butterworth at 1/128 the sample rate.
	static const double b[] = {6.321391700454014e-5, 0.00012642783400908025, 6.321391700454014e-5};
	static const double a[] = {1.0, -1.9681971279272976, 0.9684499835953156};
	
	// Apply IIR filter coefficients.
	double value = b[0]*dt_nanos;
	for(uint i = 2; i > 0; i--){

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static void do_zoom(AppState* app, tina* coro, int button, double direction){
	if(glfwGetMouseButton(app->window, button) != GLFW_PRESS) return;

	Camera* cam = &app->camera;
	double speed = 0;
	double t0 = glfwGetTime();
	while(glfwGetMouseButton(app->window, button) == GLFW_PRESS){
		double t1 = glfwGetTime();
		double dt = t1 - t0;
		t0 = t1;

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#include <string.h>

#include "tracy/TracyC.h"

#include "drift_game.h"

typedef struct PhysicsContext PhysicsContext;

typedef struct {
	uint idx0, idx1;

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// Appologies for the messy code.
// It was run through SPIRV-Cross
// I cleaned it up and renamed the variables by hand.

#version 330

layout(std140) uniform Locals
{
    mat2x4 LightMatrix;
    float LightRadius;

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/*
 * Used for culling tiles in a map renderer I wrote.
 * All tiles used geometry in the [-1, 1] range, and their mvp matrix would get precalculated.
 * So it was simply a matter of seeing if their projected OBB overlapped with the screen's clip space.
 * Returns true if the cube is visible. (false positives for near misses due to conservative w-value)
 */
static inline bool MapTileFrustumCull(const mat4 mvp){
	// Clip space center of the cube is the last column of the matrix.
	vec4 c = {mvp.m[12], mvp.m[13], mvp.m[14], mvp.m[15]};
  	// Clip space extents are the component wise absolute values of the first three columns.

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struct FragOutput {
	half4 a0 : SV_TARGET0;
	half4 a1 : SV_TARGET1;
	half4 b1 : SV_TARGET2;
	half4 a2 : SV_TARGET3;
	half4 b2 : SV_TARGET4;
};

// Double angle formula derived from the trig identity.
float2 DoubleAngle(float2 n){

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static inline fixed mulx_fast(fixed x, fixed y){return (fixed){(x.asint >> 8) * (y.asint >> 8)};}

static inline fixed mulx(fixed x, fixed y){
	bool neg = (x.asint ^ y.asint) < 0;
	union {
		u32 asint;
		struct {u16 hi, lo;};
	} _x, _y;
	
	if(x.asint >= 0) _x.asint = x.asint; else _x.asint = -x.asint;

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00000204 <start>:
 204:	1039 00a1 0001 	moveb a10001 <VDP_REG_DMA_SRC2+0xa06901>,%d0
 20a:	0200 000f      	andib #15,%d0
 20e:	6700 000c      	beqw 21c <start+0x18>
 212:	23fc 04fd 1e0d 	movel #83697165,a14000 <VDP_REG_DMA_SRC2+0xa0a900>
 218:	00a1 4000 
 21c:	4a79 00c0 0004 	tstw c00004 <VDP_CTRL>
 222:	41f9 00c0 0004 	lea c00004 <VDP_CTRL>,%a0
 228:	30bc 8004      	movew #-32764,%a0@
 22c:	30bc 8144      	movew #-32444,%a0@