From 688fee362d5812cf37cd4a19d03e01ea365c3445 Mon Sep 17 00:00:00 2001
From: cinnaboot <cinnaboot@protonmail.com>
Date: Sat, 21 Nov 2020 12:22:26 -0500
Subject: [PATCH] can't use individual uniform buffer objects for each light

we want to allow for thousands of lights eventually for deferred
lighting, and most cards have a limit of less than 15
GL_MAX_FRAGMENT_UNIFORM_BLOCKS
---
 include/lights.h        |  3 ++-
 src/default_shaders.cpp |  7 +++----
 src/lights.cpp          | 12 ++++--------
 3 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/include/lights.h b/include/lights.h
index deba1ac..cb36ba5 100644
--- a/include/lights.h
+++ b/include/lights.h
@@ -22,7 +22,8 @@ struct light_group
 	bool needs_update;
 };
 
-light_group* lightsInit(uint max_lights = 10);
+// NOTE: max_lights should match the max_lights variable in the fragment shader
+light_group* lightsInit(uint max_lights = 1000);
 
 void lightsOut(light_group* lights);
 
diff --git a/src/default_shaders.cpp b/src/default_shaders.cpp
index 70d72f6..cdd38d4 100644
--- a/src/default_shaders.cpp
+++ b/src/default_shaders.cpp
@@ -33,6 +33,8 @@ out vec4 color;
 
 uniform mat4 model;
 uniform mat3 normal_matrix;
+uniform sampler2D sampler;
+uniform uint num_lights = 0u;
 
 struct point_light {
 	uint light_ID;
@@ -40,11 +42,8 @@ struct point_light {
 	vec3 color;
 	float intensity;
 };
-#define MAX_LIGHTS 10
-uniform point_light lights[MAX_LIGHTS];
-uniform uint num_lights = 0u;
 
-uniform sampler2D sampler;
+uniform point_light lights[1000];
 
 
 void main()
diff --git a/src/lights.cpp b/src/lights.cpp
index dad58fd..c6bc9a3 100644
--- a/src/lights.cpp
+++ b/src/lights.cpp
@@ -1,4 +1,6 @@
 
+#include <sstream> // stringstream
+
 #include "lights.h"
 
 
@@ -34,22 +36,16 @@ lightsAdd(light_group* lights, glm::vec3 pos, glm::vec3 color, float intensity)
 	return true;
 }
 
-#include <sstream>
-
 void
 lightsUpdate(light_group* lights, shader_program* shader)
 {
-	// set shader max_lights uniform to match..
-	// TODO: use Uniform Buffer Objects to update light data
-	// 	https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_uniform_buffer_object.txt
-	// 	https://www.khronos.org/opengl/wiki/Uniform_Buffer_Objects
-
 	glUniform1ui(shader->num_lights_id, lights->num_lights);
 
 	for (uint i = 0; i < lights->num_lights; i++) {
 		std::stringstream ss;
 		ss << "lights[" << i << "].position";
-		int light_pos_loc = glGetUniformLocation(shader->program_id, ss.str().c_str());
+		int light_pos_loc =
+			glGetUniformLocation(shader->program_id, ss.str().c_str());
 
 		glUniform3fv(light_pos_loc, 1, &lights->lights[i].position[0]);
 	}