From da31d5c1c026e817e49dbb5a37568ec4bfa3c510 Mon Sep 17 00:00:00 2001
From: cinnaboot <cinnaboot@protonmail.com>
Date: Fri, 11 Feb 2022 10:46:59 -0500
Subject: [PATCH] add ambient_color to the LightsBuffer structure

---
 data/full_lighting.frag |  4 ++--
 src/tangerine.cpp       | 20 ++++++++++++++++----
 src/tangerine.h         |  6 ++++++
 3 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/data/full_lighting.frag b/data/full_lighting.frag
index a99a778..f157004 100644
--- a/data/full_lighting.frag
+++ b/data/full_lighting.frag
@@ -8,8 +8,6 @@ out vec4 color;
 
 uniform sampler2D sampler;
 
-// TODO: ambient light should be part of the lights uniform
-const vec4 ambient_color = vec4(0.1, 0.1, 0.1, 1);
 const uint NUM_LIGHTS = 32u;
 
 layout (std140) uniform lights
@@ -20,6 +18,8 @@ layout (std140) uniform lights
 	uint active_d_lights;
 	uint padding;
 
+	vec4 ambient_color;
+
 	vec4 pl_positions[NUM_LIGHTS];
 	vec4 pl_colors[NUM_LIGHTS];
 	uint pl_intensities[NUM_LIGHTS]; // NOTE: 16 bytes * NUM_LIGHTS
diff --git a/src/tangerine.cpp b/src/tangerine.cpp
index 763c094..f799512 100644
--- a/src/tangerine.cpp
+++ b/src/tangerine.cpp
@@ -10,13 +10,15 @@
 
 bool initGraphics(SDLHandles* handles);
 
-LightsBuffer* initLights(MemoryArena* arena, GLContext* gl_ctx, u32 max_lights);
+LightsBuffer* initLights(MemoryArena* arena, GLContext* gl_ctx, u32 max_lights,
+						glm::vec4 ambient_color);
 
 
 // interface
 
 RenderState*
 initRenderState(GLClearColor clear_col,
+	glm::vec4 ambient_color,
 	u32 max_models,
 	u32 max_textures,
 	u32 max_shaders,
@@ -56,7 +58,8 @@ initRenderState(GLClearColor clear_col,
 		assert(xforms_ubo);
 		initTransforms(rs->assets.arena, rs->xforms, xforms_ubo, rs->gl_ctx);
 
-		rs->lights_buf = initLights(rs->rg_arena, rs->gl_ctx, max_lights);
+		rs->lights_buf = initLights(rs->rg_arena, rs->gl_ctx, max_lights,
+									ambient_color);
 
 		bool ret = loadDefaultShaders(rs);
 		assert(ret);
@@ -309,12 +312,16 @@ initGraphics(SDLHandles* handles)
 }
 
 LightsBuffer*
-initLights(MemoryArena* arena, GLContext* gl_ctx, u32 max_lights)
+initLights(MemoryArena* arena,
+	GLContext* gl_ctx,
+	u32 max_lights,
+	glm::vec4 ambient_color)
 {
 	// FIXME: revisit for 'Scene' abstraction
 
 	LightsBuffer* lb = ARENA_ALLOC(arena, LightsBuffer, 1);
 	lb->buf_size = 8 * sizeof(u32) // NOTE: 'header'
+				+ sizeof(glm::vec4) // NOTE: ambient color
 				+ 6 * max_lights * sizeof(glm::vec4); // NOTE: vector arrays
 	LOGF(Debug, "buf_size: %d\n", lb->buf_size);
 	lb->buffer = ARENA_ALLOC(arena, u8, lb->buf_size);
@@ -335,9 +342,14 @@ initLights(MemoryArena* arena, GLContext* gl_ctx, u32 max_lights)
 	// 	in the future
 	void* arr_start = arenaGetAddressOffset(lb->buffer, 8 * sizeof(u32));
 
+	// NOTE: ambient color
+	lb->ambient_color = (glm::vec4*) arr_start;
+	*lb->ambient_color = ambient_color;
+
 	// NOTE: set offsets for array pointers
 	u32 arr_size = max_lights * sizeof(glm::vec4);
-	lb->pl_positions = (glm::vec4*) arr_start;
+	lb->pl_positions = //(glm::vec4*) arr_start;
+		(glm::vec4*) arenaGetAddressOffset(arr_start, sizeof(glm::vec4));
 	lb->pl_colors =
 		(glm::vec4*) arenaGetAddressOffset(lb->pl_positions, arr_size);
 	lb->pl_intensities =
diff --git a/src/tangerine.h b/src/tangerine.h
index f20f136..c804e94 100644
--- a/src/tangerine.h
+++ b/src/tangerine.h
@@ -59,6 +59,8 @@
 *  		- maybe fixed now with MeshBufferType enum and getMeshData()
 *  - allow entities to have an empty diffuse texture (see initEntity())
 *  - use dynamic shader parsing to set 'sampler_id' for shaders with textures
+*  - add ambient light to LightsBuffer structure
+*  		- remember to update offsets in initLights()
 */
 
 
@@ -132,6 +134,8 @@ struct LightsBuffer
 	u32* max_d_lights;
 	u32* active_d_lights;
 
+	glm::vec4* ambient_color;
+
 	glm::vec4* pl_positions;
 	glm::vec4* pl_colors;
 	glm::uvec4* pl_intensities;
@@ -170,8 +174,10 @@ struct RenderState
 #define DEFAULT_UBO_COUNT 32
 #define DEFAULT_RENDER_GROUP_COUNT 256
 #define DEFAULT_CLEAR_COLOR { 0.2, 0.2, 0.2, 1 }
+#define DEFAULT_AMBIENT_COLOR { 0.1, 0.1, 0.1, 1 }
 #define DEFAULT_MAX_LIGHTS 32 // NOTE: needs to match NUM_LIGHTS in shaders
 RenderState* initRenderState(GLClearColor clear_col = DEFAULT_CLEAR_COLOR,
+	glm::vec4 ambient_color = DEFAULT_AMBIENT_COLOR,
 	u32 max_models = DEFAULT_MODEL_COUNT,
 	u32 max_textures = DEFAULT_TEXTURE_COUNT,
 	u32 max_shaders = DEFAULT_SHADER_COUNT,