improve glow rendering

demo/mod/sky.fnl

@@ -1,5 +1,4 @@
 (local pxl8 (require :pxl8))
-(local effects (require :pxl8.effects))
 
 (local SKY_GRADIENT_START 144)
 (local SKY_GRADIENT_COUNT 16)
@@ -25,6 +24,7 @@
 (var sky-mesh nil)
 (var star-count 0)
 (var star-directions nil)
+(var star-glows nil)
 (var star-projected nil)
 (var star-time 0)
 (var tiny-stars [])
@@ -167,6 +167,7 @@
 
   (set star-count (+ (length tiny-stars) (length random-stars)))
   (set star-directions (pxl8.create_vec3_array star-count))
+  (set star-glows (pxl8.create_glows 10000))
   (set star-projected (pxl8.create_vec3_array star-count))
 
   (var idx 0)
@@ -185,9 +186,8 @@
 
 (fn render-stars [cam-x cam-y cam-z intensity dt]
   (set star-time (+ star-time (or dt 0)))
-  (when (and (> intensity 0) (> star-count 0))
-    (let [glows []
-          fade-in (* intensity intensity)
+  (when (and (> intensity 0) (> star-count 0) star-glows)
+    (let [fade-in (* intensity intensity)
           time-factor (/ star-time 60)
           star-rotation (/ (* star-time math.pi 2) STAR_CYCLE_PERIOD)
           t (pxl8.mat4_translate cam-x cam-y cam-z)
@@ -196,6 +196,7 @@
           transform (pxl8.mat4_multiply t (pxl8.mat4_multiply r s))
           tiny-count (length tiny-stars)]
 
+      (star-glows:clear)
       (pxl8.project_points star-directions star-projected star-count transform)
 
       (for [i 0 (- tiny-count 1)]
@@ -204,11 +205,8 @@
             (let [star (. tiny-stars (+ i 1))
                   int (math.floor (* star.brightness fade-in))]
               (when (> int 8)
-                (table.insert glows {:x (math.floor screen.x) :y (math.floor screen.y)
-                                     :radius 1
-                                     :intensity int
-                                     :color star.color
-                                     :shape effects.GLOW_CIRCLE}))))))
+                (star-glows:add (math.floor screen.x) (math.floor screen.y)
+                                1 int star.color pxl8.GLOW_CIRCLE))))))
 
       (for [i 0 (- (length random-stars) 1)]
         (let [screen (. star-projected (+ tiny-count i))]
@@ -221,33 +219,20 @@
                   sy (math.floor screen.y)]
               (if (> star.brightness 220)
                   (do
-                    (table.insert glows {:x sx :y sy :radius 3
-                                         :intensity (math.floor (* int 1.5))
-                                         :color star.color :shape effects.GLOW_DIAMOND})
-                    (table.insert glows {:x sx :y sy :radius 5
-                                         :intensity (math.floor (/ int 2))
-                                         :color star.color :shape effects.GLOW_CIRCLE}))
+                    (star-glows:add sx sy 3 (math.floor (* int 1.5)) star.color pxl8.GLOW_DIAMOND)
+                    (star-glows:add sx sy 5 (math.floor (/ int 2)) star.color pxl8.GLOW_CIRCLE))
                   (> star.brightness 180)
                   (do
-                    (table.insert glows {:x sx :y sy :radius 2 :intensity int
-                                         :color star.color :shape effects.GLOW_DIAMOND})
-                    (table.insert glows {:x sx :y sy :radius 4
-                                         :intensity (math.floor (/ int 3))
-                                         :color star.color :shape effects.GLOW_CIRCLE}))
+                    (star-glows:add sx sy 2 int star.color pxl8.GLOW_DIAMOND)
+                    (star-glows:add sx sy 4 (math.floor (/ int 3)) star.color pxl8.GLOW_CIRCLE))
                   (> star.brightness 120)
                   (do
-                    (table.insert glows {:x sx :y sy :radius 2
-                                         :intensity (math.floor (* int 0.67))
-                                         :color star.color :shape effects.GLOW_DIAMOND})
-                    (table.insert glows {:x sx :y sy :radius 3
-                                         :intensity (math.floor (/ int 4))
-                                         :color star.color :shape effects.GLOW_CIRCLE}))
-                  (table.insert glows {:x sx :y sy :radius 2
-                                       :intensity (math.floor (* int 0.5))
-                                       :color star.color :shape effects.GLOW_CIRCLE}))))))
+                    (star-glows:add sx sy 2 (math.floor (* int 0.67)) star.color pxl8.GLOW_DIAMOND)
+                    (star-glows:add sx sy 3 (math.floor (/ int 4)) star.color pxl8.GLOW_CIRCLE))
+                  (star-glows:add sx sy 2 (math.floor (* int 0.5)) star.color pxl8.GLOW_CIRCLE))))))
 
-      (when (> (length glows) 0)
-        (effects.glows glows)))))
+      (when (> (star-glows:count) 0)
+        (star-glows:render)))))
 
 (fn render [cam-x cam-y cam-z wireframe]
   (when (not sky-mesh) (create-sky-dome))

pxl8.sh

@@ -395,6 +395,7 @@ case "$COMMAND" in
             src/gfx/pxl8_dither.c
             src/gfx/pxl8_font.c
             src/gfx/pxl8_gfx.c
+            src/gfx/pxl8_glows.c
             src/gfx/pxl8_lightmap.c
             src/gfx/pxl8_mesh.c
             src/gfx/pxl8_palette.c

src/gfx/pxl8_glows.c

@@ -0,0 +1,59 @@
+#include "pxl8_glows.h"
+
+#include <stdlib.h>
+
+struct pxl8_glows {
+    pxl8_glow_source* data;
+    u32 capacity;
+    u32 count;
+};
+
+pxl8_glows* pxl8_glows_create(u32 capacity) {
+    pxl8_glows* glows = calloc(1, sizeof(pxl8_glows));
+    if (!glows) return NULL;
+
+    glows->data = calloc(capacity, sizeof(pxl8_glow_source));
+    if (!glows->data) {
+        free(glows);
+        return NULL;
+    }
+
+    glows->capacity = capacity;
+    glows->count = 0;
+
+    return glows;
+}
+
+void pxl8_glows_destroy(pxl8_glows* glows) {
+    if (!glows) return;
+    free(glows->data);
+    free(glows);
+}
+
+void pxl8_glows_add(pxl8_glows* glows, i16 x, i16 y, u8 radius, u16 intensity, u8 color, u8 shape) {
+    if (!glows || glows->count >= glows->capacity) return;
+
+    pxl8_glow_source* g = &glows->data[glows->count++];
+    g->x = x;
+    g->y = y;
+    g->radius = radius;
+    g->intensity = intensity;
+    g->color = color;
+    g->shape = shape;
+    g->depth = 0xFFFF;
+    g->height = 0;
+}
+
+void pxl8_glows_clear(pxl8_glows* glows) {
+    if (!glows) return;
+    glows->count = 0;
+}
+
+u32 pxl8_glows_count(const pxl8_glows* glows) {
+    return glows ? glows->count : 0;
+}
+
+void pxl8_glows_render(pxl8_glows* glows, pxl8_gfx* gfx) {
+    if (!glows || !gfx || glows->count == 0) return;
+    pxl8_gfx_apply_effect(gfx, PXL8_GFX_EFFECT_GLOWS, glows->data, glows->count);
+}

src/gfx/pxl8_glows.h

@@ -0,0 +1,22 @@
+#pragma once
+
+#include "pxl8_gfx.h"
+#include "pxl8_types.h"
+
+typedef struct pxl8_glows pxl8_glows;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+pxl8_glows* pxl8_glows_create(u32 capacity);
+void pxl8_glows_destroy(pxl8_glows* glows);
+
+void pxl8_glows_add(pxl8_glows* glows, i16 x, i16 y, u8 radius, u16 intensity, u8 color, u8 shape);
+void pxl8_glows_clear(pxl8_glows* glows);
+u32 pxl8_glows_count(const pxl8_glows* glows);
+void pxl8_glows_render(pxl8_glows* glows, pxl8_gfx* gfx);
+
+#ifdef __cplusplus
+}
+#endif

src/lua/pxl8.lua

@@ -1,6 +1,7 @@
 local anim = require("pxl8.anim")
 local bytes = require("pxl8.bytes")
 local core = require("pxl8.core")
+local effects = require("pxl8.effects")
 local gfx2d = require("pxl8.gfx2d")
 local gfx3d = require("pxl8.gfx3d")
 local gui = require("pxl8.gui")
@@ -98,6 +99,12 @@ pxl8.draw_mesh = gfx3d.draw_mesh
 pxl8.end_frame_3d = gfx3d.end_frame
 pxl8.project_points = gfx3d.project_points
 
+pxl8.GLOW_CIRCLE = effects.GLOW_CIRCLE
+pxl8.GLOW_DIAMOND = effects.GLOW_DIAMOND
+pxl8.GLOW_SHAFT = effects.GLOW_SHAFT
+pxl8.Glows = effects.Glows
+pxl8.create_glows = effects.Glows.new
+
 pxl8.Compressor = sfx.Compressor
 pxl8.create_compressor = sfx.Compressor.new
 pxl8.Delay = sfx.Delay

src/lua/pxl8/effects.lua

@@ -8,25 +8,40 @@ effects.GLOW_CIRCLE = 0
 effects.GLOW_DIAMOND = 1
 effects.GLOW_SHAFT = 2
 
-function effects.glows(glows)
-    if not glows or #glows == 0 then return end
+local Glows = {}
+Glows.__index = Glows
 
-    local count = #glows
-    local glow_array = ffi.new("pxl8_glow_source[?]", count)
-
-    for i, g in ipairs(glows) do
-        local idx = i - 1
-        glow_array[idx].x = g.x or 0
-        glow_array[idx].y = g.y or 0
-        glow_array[idx].radius = g.radius or 8
-        glow_array[idx].intensity = g.intensity or 255
-        glow_array[idx].color = g.color or 15
-        glow_array[idx].depth = g.depth or 0xFFFF
-        glow_array[idx].height = g.height or 0
-        glow_array[idx].shape = g.shape or 0
+function Glows.new(capacity)
+    local ptr = C.pxl8_glows_create(capacity or 1000)
+    if ptr == nil then
+        return nil
+    end
+    return setmetatable({ _ptr = ptr }, Glows)
 end
 
-    C.pxl8_gfx_apply_effect(core.gfx, C.PXL8_GFX_EFFECT_GLOWS, glow_array, count)
+function Glows:add(x, y, radius, intensity, color, shape)
+    C.pxl8_glows_add(self._ptr, x, y, radius or 8, intensity or 255, color or 15, shape or 0)
 end
 
+function Glows:clear()
+    C.pxl8_glows_clear(self._ptr)
+end
+
+function Glows:count()
+    return C.pxl8_glows_count(self._ptr)
+end
+
+function Glows:destroy()
+    if self._ptr then
+        C.pxl8_glows_destroy(self._ptr)
+        self._ptr = nil
+    end
+end
+
+function Glows:render()
+    C.pxl8_glows_render(self._ptr, core.gfx)
+end
+
+effects.Glows = Glows
+
 return effects

src/script/pxl8_script_ffi.h

@@ -249,6 +249,14 @@ static const char* pxl8_ffi_cdefs =
 "\n"
 "void pxl8_gfx_apply_effect(pxl8_gfx* gfx, pxl8_gfx_effect effect, const void* params, u32 count);\n"
 "void pxl8_gfx_blend_tables_update(pxl8_gfx* gfx);\n"
+"\n"
+"typedef struct pxl8_glows pxl8_glows;\n"
+"pxl8_glows* pxl8_glows_create(u32 capacity);\n"
+"void pxl8_glows_destroy(pxl8_glows* glows);\n"
+"void pxl8_glows_add(pxl8_glows* glows, i16 x, i16 y, u8 radius, u16 intensity, u8 color, u8 shape);\n"
+"void pxl8_glows_clear(pxl8_glows* glows);\n"
+"u32 pxl8_glows_count(const pxl8_glows* glows);\n"
+"void pxl8_glows_render(pxl8_glows* glows, pxl8_gfx* gfx);\n"
 "void pxl8_gfx_colormap_update(pxl8_gfx* gfx);\n"
 "\n"
 "void pxl8_3d_begin_frame(pxl8_gfx* gfx, const pxl8_3d_camera* camera, const pxl8_3d_uniforms* uniforms);\n"