From 8f77e33f3359f347d0577835694af348939b3afe Mon Sep 17 00:00:00 2001
From: cinnaboot <cinnaboot@protonmail.com>
Date: Sat, 12 Feb 2022 11:24:00 -0500
Subject: [PATCH] use rg_arena for storing GLMesh buffers

---
 src/entity.cpp  | 11 ++++++-----
 src/shader.cpp  | 32 ++++++++++----------------------
 src/shader.h    |  3 ++-
 src/tangerine.h |  1 +
 4 files changed, 19 insertions(+), 28 deletions(-)

diff --git a/src/entity.cpp b/src/entity.cpp
index b819687..7c8f7f5 100644
--- a/src/entity.cpp
+++ b/src/entity.cpp
@@ -29,11 +29,12 @@ initEntity(Entity* e,
 
 	for (u32 i = 0; i< e->num_meshes; i++) {
 		GLMesh* glm = &e->meshes[i];
-		*glm = loadGLMesh(mdl->meshes[i],
-					GL_TRIANGLES,
-					e->diffuse_texture,
-					num_attrib_mappings,
-					attrib_mappings);
+		*glm = loadGLMesh(arena,
+						mdl->meshes[i],
+						GL_TRIANGLES,
+						e->diffuse_texture,
+						num_attrib_mappings,
+						attrib_mappings);
 
 		if (glm->vao_id == 0) {
 			LOGF(Error, "error initializing entity\n");
diff --git a/src/shader.cpp b/src/shader.cpp
index 242d928..181b208 100644
--- a/src/shader.cpp
+++ b/src/shader.cpp
@@ -300,16 +300,19 @@ getVertexAttribByName(ShaderProgram* shader, const char* name)
 }
 
 GLMesh
-initGLMesh(const Mesh& m, u32 num_mappings, GLenum draw_mode)
+initGLMesh(MemoryArena* arena,
+		const Mesh& m,
+		u32 num_mappings,
+		GLenum draw_mode)
 {
 	GLMesh glm = {0};
 	glm.num_indices = m.num_indices;
 	glm.draw_mode = draw_mode;
 	glm.usage = GL_STATIC_DRAW; // TODO: logic for updating dynamic meshes
 	glm.num_vertex_attrib_buffers = num_mappings;
-	glm.vertex_attrib_buffers = UTIL_ALLOC(num_mappings, GLBuffer);
-	glm.element_buf = UTIL_ALLOC(1, GLBuffer);
-	glm.node_xform = UTIL_ALLOC(1, glm::mat4);
+	glm .vertex_attrib_buffers = ARENA_ALLOC(arena, GLBuffer, num_mappings);
+	glm.element_buf = ARENA_ALLOC(arena, GLBuffer, 1);
+	glm.node_xform = ARENA_ALLOC(arena, glm::mat4, 1);
 	*glm.node_xform = glm::mat4(1);
 
 	return glm;
@@ -328,15 +331,14 @@ initGLAttribBuffer(GLBuffer* buf, GLenum target, GLVertexAttrib* attrib)
 // FIXME: might as well pass in pointer to GLMesh, since that's how we're
 // 	going to use this, can void copying GLMesh twice that way
 GLMesh
-loadGLMesh(const Mesh& m,
+loadGLMesh(MemoryArena* arena,
+	const Mesh& m,
 	GLenum draw_mode,
 	GLTexture* diffuse_texture,
 	u32 num_mappings,
 	GLBufferToAttribMapping mappings[])
 {
-	// NOTE: need to use freeGLMesh() when freeing because we're not storing
-	// 	the GLBuffers on a memory arean (yet)
-	GLMesh glm = initGLMesh(m, num_mappings, draw_mode);
+	GLMesh glm = initGLMesh(arena, m, num_mappings, draw_mode);
 
 	if (diffuse_texture) {
 		glm.has_texture = true;
@@ -384,20 +386,6 @@ loadGLMesh(const Mesh& m,
 	return glm;
 }
 
-void
-freeGLMesh(GLMesh* glm)
-{
-	if (glm) {
-		for (u32 i = 0; i < glm->num_vertex_attrib_buffers; i++)
-			utilSafeFree(glm->vertex_attrib_buffers[i].name);
-
-		utilSafeFree(glm->vertex_attrib_buffers);
-		utilSafeFree(glm->element_buf);
-		// NOTE: don't free the GLMesh because it is part of a memory arena
-		//utilSafeFree(glm);
-	}
-}
-
 
 // NOTE: internal
 
diff --git a/src/shader.h b/src/shader.h
index 0561a67..898fa9e 100644
--- a/src/shader.h
+++ b/src/shader.h
@@ -205,7 +205,8 @@ void renderVAO(GLMesh* glmesh,
 
 GLVertexAttrib* getVertexAttribByName(ShaderProgram* shader, const char* name);
 
-GLMesh loadGLMesh(const Mesh& m,
+GLMesh loadGLMesh(MemoryArena* arena,
+	const Mesh& m,
 	GLenum draw_mode,
 	GLTexture* diffuse_texture,
 	u32 num_mappings,
diff --git a/src/tangerine.h b/src/tangerine.h
index c804e94..f29aae4 100644
--- a/src/tangerine.h
+++ b/src/tangerine.h
@@ -61,6 +61,7 @@
 *  - use dynamic shader parsing to set 'sampler_id' for shaders with textures
 *  - add ambient light to LightsBuffer structure
 *  		- remember to update offsets in initLights()
+*  - use rg_arena for store GLMeshes, see initGLMesh()
 */