Dawn/src/display/texture.h

81 lines
2.5 KiB
C

// Copyright (c) 2021 Dominic Masters
//
// This software is released under the MIT License.
// https://opensource.org/licenses/MIT
#pragma once
#include "../libs.h"
#define TEXTURE_SLOTS_MAX 8
/** Texture slot that a texture can be bound to */
typedef GLuint textureslot_t;
/**
* Structure detailing information about a texture.
* Because we plan to upload the pixels of a texture into the GPU, we don't
* store the pixels in memory because we don't need to!
*/
typedef struct {
/** Width (in pixels) of the texture */
int32_t width;
/** Height (in pixels) of the texture */
int32_t height;
/** Texture ID on the GPU */
GLuint id;
} texture_t;
/** Information about a single pixel. */
typedef struct {
/** RGBA Color values */
uint8_t r, g, b, a;
} pixel_t;
#define PIXEL_COLOR_WHITE ((pixel_t){ .r = 255, .g = 255, .b = 255, .a = 255 })
#define PIXEL_COLOR_RED ((pixel_t){ .r = 255, .g = 0, .b = 0, .a = 255 })
#define PIXEL_COLOR_GREEN ((pixel_t){ .r = 0, .g = 255, .b = 0, .a = 255 })
#define PIXEL_COLOR_BLUE ((pixel_t){ .r = 0, .g = 0, .b = 255, .a = 255 })
#define PIXEL_COLOR_BLACK ((pixel_t){ .r = 0, .g = 0, .b = 0, .a = 255 })
#define PIXEL_COLOR_TRANSPARENT ((pixel_t){ .r = 0, .g = 0, .b = 0, .a = 0 })
/**
* Initializes a texture that can be written in to.
*
* @param texture Texture to initialize.
* @param width Width of the texture (in pixels).
* @param height Height of the texture (in pixels).
* @param pixels Default pixel array, set to NULL to set all pixel data to 0.
*/
void textureInit(texture_t *texture, int32_t width, int32_t height,
pixel_t *pixels
);
/**
* Bind a texture on to a given texture slot.
*
* @param texture Texture to bind.
* @param slot Slot to bind the texture to.
*/
void textureBind(texture_t *texture, textureslot_t slot);
/**
* Buffer pixel data onto the GPU. Pixel buffering is rather costly so avoid
* doing this too often.
*
* @param texture Texture to buffer in to.
* @param x X coordinate in texture space to render to.
* @param y Y coordinate in texture space to render to.
* @param width Width of the pixel region you're buffering.
* @param height Height of the pixel region you're buffering.
* @param pixels Array of pixels to buffer onto the GPU.
*/
void textureBufferPixels(texture_t *texture,
int32_t x, int32_t y, int32_t width, int32_t height, pixel_t *pixels
);
/**
* Clean a previously created texture.
*
* @param texture Texture to clean up.
*/
void textureDispose(texture_t *texture);