[glsl] Update particle arrays when maximum changes

The cvar setup for particles is a bit wonky in that the arrays get
initialized using the default max particle count but never updated.
Though things could be improved some more, this solution works (and has
been more or less copied to gl, but I couldn't reproduce the crash
there, or even the valgrind error).

libs/video/renderer/gl/gl_dyn_part.c

@@ -63,23 +63,23 @@ static int						pVAsize;
 static int					   *pVAindices;
 static varray_t2f_c4ub_v3f_t   *particleVertexArray;
 
-void
+static void
-gl_R_InitParticles (void)
+alloc_arrays (psystem_t *ps)
 {
 	int		i;
 
-	if (r_psystem.maxparticles && r_init) {
+	if (ps->maxparticles && r_init) {
 		if (vaelements) {
 			partUseVA = 0;
-			pVAsize = r_psystem.maxparticles * 4;
+			pVAsize = ps->maxparticles * 4;
 			Sys_MaskPrintf (SYS_dev,
 							"Particles: Vertex Array use disabled.\n");
 		} else {
 			if (vaelements > 3)
 				pVAsize = min ((unsigned int) (vaelements - (vaelements % 4)),
-							   r_psystem.maxparticles * 4);
+							   ps->maxparticles * 4);
 			else if (vaelements >= 0)
-				pVAsize = r_psystem.maxparticles * 4;
+				pVAsize = ps->maxparticles * 4;
 			Sys_MaskPrintf (SYS_dev,
 							"Particles: %i maximum vertex elements.\n",
 							pVAsize);
@@ -109,6 +109,12 @@ gl_R_InitParticles (void)
 	}
 }
 
+void
+gl_R_InitParticles (void)
+{
+	alloc_arrays (&r_psystem);
+}
+
 void
 gl_R_DrawParticles (psystem_t *psystem)
 {
@@ -238,12 +244,14 @@ static void
 r_particles_f (cvar_t *var)
 {
 	R_MaxParticlesCheck (var, r_particles_max);
+	alloc_arrays (&r_psystem);
 }
 
 static void
 r_particles_max_f (cvar_t *var)
 {
 	R_MaxParticlesCheck (r_particles, var);
+	alloc_arrays (&r_psystem);
 }
 
 void

libs/video/renderer/glsl/glsl_particles.c

@@ -63,6 +63,7 @@
 # define GL_VERTEX_PROGRAM_POINT_SIZE 0x8642
 #endif
 
+static uint32_t     maxparticles;
 static GLushort    *pVAindices;
 static partvert_t  *particleVertexArray;
 
@@ -130,11 +131,34 @@ static struct {
 	{"fog", 1},
 };
 
+static void
+alloc_arrays (psystem_t *ps)
+{
+	if (ps->maxparticles > maxparticles) {
+		maxparticles = ps->maxparticles;
+		if (particleVertexArray)
+			free (particleVertexArray);
+		particleVertexArray = calloc (ps->maxparticles * 4,
+									  sizeof (partvert_t));
+
+		if (pVAindices)
+			free (pVAindices);
+		pVAindices = calloc (ps->maxparticles * 6, sizeof (GLushort));
+		for (uint32_t i = 0; i < ps->maxparticles; i++) {
+			pVAindices[i * 6 + 0] = i * 4 + 0;
+			pVAindices[i * 6 + 1] = i * 4 + 1;
+			pVAindices[i * 6 + 2] = i * 4 + 2;
+			pVAindices[i * 6 + 3] = i * 4 + 0;
+			pVAindices[i * 6 + 4] = i * 4 + 2;
+			pVAindices[i * 6 + 5] = i * 4 + 3;
+		}
+	}
+}
+
 void
 glsl_R_InitParticles (void)
 {
 	shader_t   *vert_shader, *frag_shader;
-	unsigned    i;
 	int         vert;
 	int         frag;
 	float       v[2] = {0, 0};
@@ -196,22 +220,7 @@ glsl_R_InitParticles (void)
 					   GL_UNSIGNED_BYTE, tex->data);
 	free (tex);
 
-	if (particleVertexArray)
+	alloc_arrays (&r_psystem);
-		free (particleVertexArray);
-	particleVertexArray = calloc (r_psystem.maxparticles * 4,
-								  sizeof (partvert_t));
-
-	if (pVAindices)
-		free (pVAindices);
-	pVAindices = calloc (r_psystem.maxparticles * 6, sizeof (GLushort));
-	for (i = 0; i < r_psystem.maxparticles; i++) {
-		pVAindices[i * 6 + 0] = i * 4 + 0;
-		pVAindices[i * 6 + 1] = i * 4 + 1;
-		pVAindices[i * 6 + 2] = i * 4 + 2;
-		pVAindices[i * 6 + 3] = i * 4 + 0;
-		pVAindices[i * 6 + 4] = i * 4 + 2;
-		pVAindices[i * 6 + 5] = i * 4 + 3;
-	}
 }
 
 static void
@@ -426,12 +435,14 @@ static void
 r_particles_f (cvar_t *var)
 {
 	R_MaxParticlesCheck (var, r_particles_max);
+	alloc_arrays (&r_psystem);
 }
 
 static void
 r_particles_max_f (cvar_t *var)
 {
 	R_MaxParticlesCheck (r_particles, var);
+	alloc_arrays (&r_psystem);
 }
 
 void