add: cubemap_sh_blend

bind/v4k.lua

@@ -1128,6 +1128,7 @@ typedef struct cubemap_t {
  void cubemap_sh_reset(cubemap_t *c);
  void cubemap_sh_shader(cubemap_t *c);
  void cubemap_sh_add_light(cubemap_t *c, vec3 light, vec3 dir, float strength);
+ void cubemap_sh_blend(vec3 pos, float max_dist, unsigned count, cubemap_t *probes);
  unsigned fbo( unsigned texture_color, unsigned texture_depth, int wr_flags );
  void fbo_bind(unsigned id);
  void fbo_unbind();

demos/09-envmap.c

@@ -103,7 +103,7 @@ int main(int argc, char** argv) {
             skybox_render(&sky, cam.proj, cam.view);
 
             shader_bind(mdl.program);
-            shader_vec3v("u_coefficients_sh", 9, env_probe.cubemap.sh);
+            cubemap_sh_blend(vec3(0,0,0), 10.0f, 1, &env_probe.cubemap);
             shader_int("u_textured", false);
 
             model_render(mdl, cam.proj, cam.view, mdl.pivot, 0);

engine/joint/v4k.h

@@ -17231,6 +17231,9 @@ API void       cubemap_sh_reset(cubemap_t *c);
 API void       cubemap_sh_shader(cubemap_t *c);
 API void       cubemap_sh_add_light(cubemap_t *c, vec3 light, vec3 dir, float strength);
 
+// lighting probe blending
+API void       cubemap_sh_blend(vec3 pos, float max_dist, unsigned count, cubemap_t *probes);
+
 // -----------------------------------------------------------------------------
 // fbos
 
@@ -383891,6 +383894,31 @@ void cubemap_sh_add_light(cubemap_t *c, vec3 light, vec3 dir, float strength) {
     c->sh[3] = add3(c->sh[3], scale3(scaled_light, -0.488603f * norm_dir.x));
 }
 
+void cubemap_sh_blend(vec3 pos, float max_dist, unsigned count, cubemap_t *probes) {
+    float total_weight = 0.0f;
+    vec3 final_sh[9] = {0};
+
+    // Iterate through each probe
+    for (unsigned i = 0; i < count; i++) {
+        float distance = len3(sub3(pos, probes[i].pos));
+        float weight = 1.0f - (distance / max_dist);
+        weight = weight * weight;
+
+        for (int s = 0; s < 9; s++) {
+            final_sh[s] = add3(final_sh[s], scale3(probes[i].sh[s], weight));
+        }
+
+        total_weight += weight;
+    }
+
+    // Normalize the final SH coefficients
+    for (int s = 0; s < 9; s++) {
+        final_sh[s] = scale3(final_sh[s], 1.0f / total_weight);
+    }
+
+    // Apply SH coefficients to the shader
+    shader_vec3v("u_coefficients_sh", 9, final_sh);
+}
 
 // -----------------------------------------------------------------------------
 // skyboxes

engine/split/v4k_render.c

@@ -2207,6 +2207,31 @@ void cubemap_sh_add_light(cubemap_t *c, vec3 light, vec3 dir, float strength) {
     c->sh[3] = add3(c->sh[3], scale3(scaled_light, -0.488603f * norm_dir.x));
 }
 
+void cubemap_sh_blend(vec3 pos, float max_dist, unsigned count, cubemap_t *probes) {
+    float total_weight = 0.0f;
+    vec3 final_sh[9] = {0};
+
+    // Iterate through each probe
+    for (unsigned i = 0; i < count; i++) {
+        float distance = len3(sub3(pos, probes[i].pos));
+        float weight = 1.0f - (distance / max_dist);
+        weight = weight * weight;
+
+        for (int s = 0; s < 9; s++) {
+            final_sh[s] = add3(final_sh[s], scale3(probes[i].sh[s], weight));
+        }
+
+        total_weight += weight;
+    }
+
+    // Normalize the final SH coefficients
+    for (int s = 0; s < 9; s++) {
+        final_sh[s] = scale3(final_sh[s], 1.0f / total_weight);
+    }
+
+    // Apply SH coefficients to the shader
+    shader_vec3v("u_coefficients_sh", 9, final_sh);
+}
 
 // -----------------------------------------------------------------------------
 // skyboxes

engine/split/v4k_render.h

@@ -263,6 +263,9 @@ API void       cubemap_sh_reset(cubemap_t *c);
 API void       cubemap_sh_shader(cubemap_t *c);
 API void       cubemap_sh_add_light(cubemap_t *c, vec3 light, vec3 dir, float strength);
 
+// lighting probe blending
+API void       cubemap_sh_blend(vec3 pos, float max_dist, unsigned count, cubemap_t *probes);
+
 // -----------------------------------------------------------------------------
 // fbos
 

engine/v4k.c

@@ -19006,6 +19006,31 @@ void cubemap_sh_add_light(cubemap_t *c, vec3 light, vec3 dir, float strength) {
     c->sh[3] = add3(c->sh[3], scale3(scaled_light, -0.488603f * norm_dir.x));
 }
 
+void cubemap_sh_blend(vec3 pos, float max_dist, unsigned count, cubemap_t *probes) {
+    float total_weight = 0.0f;
+    vec3 final_sh[9] = {0};
+
+    // Iterate through each probe
+    for (unsigned i = 0; i < count; i++) {
+        float distance = len3(sub3(pos, probes[i].pos));
+        float weight = 1.0f - (distance / max_dist);
+        weight = weight * weight;
+
+        for (int s = 0; s < 9; s++) {
+            final_sh[s] = add3(final_sh[s], scale3(probes[i].sh[s], weight));
+        }
+
+        total_weight += weight;
+    }
+
+    // Normalize the final SH coefficients
+    for (int s = 0; s < 9; s++) {
+        final_sh[s] = scale3(final_sh[s], 1.0f / total_weight);
+    }
+
+    // Apply SH coefficients to the shader
+    shader_vec3v("u_coefficients_sh", 9, final_sh);
+}
 
 // -----------------------------------------------------------------------------
 // skyboxes

engine/v4k.h

@@ -3298,6 +3298,9 @@ API void       cubemap_sh_reset(cubemap_t *c);
 API void       cubemap_sh_shader(cubemap_t *c);
 API void       cubemap_sh_add_light(cubemap_t *c, vec3 light, vec3 dir, float strength);
 
+// lighting probe blending
+API void       cubemap_sh_blend(vec3 pos, float max_dist, unsigned count, cubemap_t *probes);
+
 // -----------------------------------------------------------------------------
 // fbos