texture.h File Reference

Image loading and GPU texture management. More...

#include "gl_common.h"
#include <stdint.h>

Include dependency graph for texture.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Enumerations
enum	{ MAX_TEXTURE_DIMENSION = 8192 }

Functions
void	texture_ensure_pbo (GLuint *pbo_id, GLsizeiptr *current_size, GLsizeiptr required_size)
	Ensures a PBO is allocated with sufficient size. More...
void *	texture_map_pbo (GLuint pbo_id, size_t size_bytes)
	Maps a PBO for writing. More...
GLuint	texture_preallocate_hdr (int width, int height, GLuint old_tex)
	Pre-allocates VRAM for an HDR texture (glTexStorage2D only). More...
GLuint	texture_upload_hdr_from_pbo (GLuint pbo_id, void *ptr, int width, int height, GLuint reuse_tex_id)
	Finalizes HDR upload from a PBO (Unmap -> Upload -> Mipmaps). More...
void	texture_generate_hdr_mipmap (GLuint tex)
	Generates mipmaps for an HDR texture. More...
float *	texture_load_pixels (const char *path, int *width, int *height, int *channels)
	Decodes an HDR image into RAM without uploading to GPU. More...
GLuint	texture_load_rgba_png (const char *path)
	Loads a PNG image from disk and creates an OpenGL RGBA texture. More...

Detailed Description

Image loading and GPU texture management.

Enumeration Type Documentation

anonymous enum

anonymous enum

Enumerator
MAX_TEXTURE_DIMENSION

Function Documentation

texture_ensure_pbo()

void texture_ensure_pbo	(	GLuint *	pbo_id,
		GLsizeiptr *	current_size,
		GLsizeiptr	required_size
	)

Ensures a PBO is allocated with sufficient size.

Checks if internal *current_size is >= required_size. If not, reallocates (orphans) the buffer using glBufferData.

Parameters

pbo_id	Pointer to the PBO ID (generated if 0).
current_size	Pointer to the currently tracking size (updated on realloc).
required_size	The minimum size needed.

texture_generate_hdr_mipmap()

void texture_generate_hdr_mipmap

(

GLuint

tex

)

Generates mipmaps for an HDR texture.

Parameters

tex	The OpenGL ID of the texture.

texture_load_pixels()

float* texture_load_pixels	(	const char *	path,
		int *	width,
		int *	height,
		int *	channels
	)

Decodes an HDR image into RAM without uploading to GPU.

Useful for asynchronous loading or CPU-side processing.

Parameters

	path	File system path.
[out]	width	Width.
[out]	height	Height.
[out]	channels	Number of color channels.

Returns

Pointer to heap-allocated data. Buffer must be freed by caller.

Here is the call graph for this function:

texture_load_rgba_png()

GLuint texture_load_rgba_png

(

const char *

path

)

Loads a PNG image from disk and creates an OpenGL RGBA texture.

Parameters

path	File system path to the PNG image.

Returns

GLuint The OpenGL texture ID, or 0 on failure.

texture_map_pbo()

void* texture_map_pbo	(	GLuint	pbo_id,
		size_t	size_bytes
	)

Maps a PBO for writing.

Parameters

pbo_id	ID of the PBO to map.
size_bytes	Size to map (should match creation size).

Returns

Pointer to mapped memory, or NULL on failure.

texture_preallocate_hdr()

GLuint texture_preallocate_hdr	(	int	width,
		int	height,
		GLuint	old_tex
	)

Pre-allocates VRAM for an HDR texture (glTexStorage2D only).

Call this early (e.g. when async loader requests a PBO) to spread the cost of texture allocation across frames. If old_tex already matches the requested dimensions, it is returned as-is (zero-cost reuse).

Parameters

width	Texture width.
height	Texture height.
old_tex	Existing texture ID to check for reuse (0 if none).

Returns

GLuint Pre-allocated texture ID, or 0 on failure.

Here is the call graph for this function:

texture_upload_hdr_from_pbo()

GLuint texture_upload_hdr_from_pbo	(	GLuint	pbo_id,
		void *	ptr,
		int	width,
		int	height,
		GLuint	reuse_tex_id
	)

Finalizes HDR upload from a PBO (Unmap -> Upload -> Mipmaps).

Parameters

pbo_id	ID of the PBO (must be bound).
ptr	Pointer to the mapped PBO memory (will be unmapped).
width	Texture width.
height	Texture height.
reuse_tex_id	Existing texture ID to update/reuse.

Returns

GLuint The texture ID (new or reused).

Here is the call graph for this function: