rdpq_tex.c File Reference

RDP Command queue: texture loading. More...

Data Structures
struct	rdpq_multi_upload_t
	Non-zero if we are doing a multi-texture upload. More...

Macros
#define	TMEM_PALETTE_ADDR   0x800
	Address in TMEM where the palettes must be loaded.

Functions
int	integer_to_pow2 (int x)
	Calculates the first power of 2 that is equal or larger than size. More...
int	rdpq_tex_upload_sub (rdpq_tile_t tile, const surface_t *tex, const rdpq_texparms_t *parms, int s0, int t0, int s1, int t1)
	Load a portion of texture into TMEM. More...
int	rdpq_tex_upload (rdpq_tile_t tile, const surface_t *tex, const rdpq_texparms_t *parms)
	Load a texture into TMEM. More...
int	rdpq_tex_reuse_sub (rdpq_tile_t tile, const rdpq_texparms_t *parms, int s0, int t0, int s1, int t1)
	Reuse a portion of the previously uploaded texture to TMEM. More...
int	rdpq_tex_reuse (rdpq_tile_t tile, const rdpq_texparms_t *parms)
	Reuse the previously uploaded texture to TMEM. More...
void	__rdpq_tex_blit (const surface_t *surf, float x0, float y0, const rdpq_blitparms_t *parms, large_tex_draw ltd)
	Internal implementation of rdpq_tex_blit, using a custom large tex loader callback function.
void	rdpq_tex_blit (const surface_t *surf, float x0, float y0, const rdpq_blitparms_t *parms)
	Blit a surface to the active framebuffer. More...
void	rdpq_tex_upload_tlut (uint16_t *tlut, int color_idx, int num_colors)
	Load one or more palettes into TMEM. More...
void	rdpq_tex_multi_begin (void)
	Begin a multi-texture upload. More...
int	rdpq_tex_multi_end (void)
	Finish a multi-texture upload. More...

Variables
tex_loader_t	last_tload
	Information on last image uploaded we are doing a multi-texture upload.

Detailed Description

RDP Command queue: texture loading.

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Data Structure Documentation

rdpq_multi_upload_t

struct rdpq_multi_upload_t

Non-zero if we are doing a multi-texture upload.

Data Fields
int	used
int	bytes
int	limit

Function Documentation

integer_to_pow2()

int integer_to_pow2

(

int

x

)

Calculates the first power of 2 that is equal or larger than size.

Parameters

x	input in units

Returns

Power of 2 that is equal or larger than x

rdpq_tex_upload_sub()

int rdpq_tex_upload_sub	(	rdpq_tile_t	tile,
		const surface_t *	tex,
		const rdpq_texparms_t *	parms,
		int	s0,
		int	t0,
		int	s1,
		int	t1
	)

Load a portion of texture into TMEM.

This function is similar to rdpq_tex_upload, but only loads a portion of a texture in TMEM. The portion is specified as a rectangle (with exclusive bounds) that must be contained within the original texture.

Notice that, after calling this function, you must draw the polygon using texture coordinates that are contained within the loaded ones. For instance:

// Load a 32x32 sprite starting at position (100,100) in the
// "spritemap" surface.
rdpq_tex_upload_sub(TILE2, spritemap, 0, 100, 100, 132, 132);
 
// Draw the sprite. Notice that we must refer to it using the
// original texture coordinates, even if just that portion is in TMEM.
rdpq_texture_rectangle(TILE2,
    pos_x, pos_y, pos_x+32, pos_y+32,   // screen coordinates of the sprite
    100, 100,                           // texture coordinates
    1.0, 1.0);                          // texture increments (= no scaling)

An alternative to this function is to call surface_make_sub on the texture to create a sub-surface, and then call rdpq_tex_upload on the sub-surface. The same data will be loaded into TMEM but this time the RDP ignores that you are loading a portion of a larger texture:

// Create a sub-surface of spritemap texture. No memory allocations
// or pixel copies are performed, this is just a rectangular "window"
// into the original texture.
surface_t hero = surface_make_sub(spritemap, 100, 100, 32, 32);
 
// Load the sub-surface. Notice that the RDP is unaware that it is
// a sub-surface; it will think that it is a whole texture.
rdpq_tex_upload(TILE2, &hero, 0);
 
// Draw the sprite. Notice that we must refer to it using
// texture coordinates (0,0).
rdpq_texture_rectangle(TILE2,
    pos_x, pos_y, pos_x+32, pos_y+32,   // screen coordinates of the sprite
    0, 0,                               // texture coordinates
    1.0, 1.0);                          // texture increments (= no scaling)

The only limit of this second solution is that the sub-surface pointer must be 8-byte aligned (like all RDP textures), so it can only be used if the rectangle that needs to be loaded respects such constraint as well.

Parameters

tile	Tile descriptor that will be initialized with this texture
tex	Surface containing the texture to load
parms	All optional parameters on where to load the texture and how to sample it. Refer to rdpq_texparms_t for more information.
s0	Top-left X coordinate of the rectangle to load
t0	Top-left Y coordinate of the rectangle to load
s1	Bottom-right exclusive X coordinate of the rectangle
t1	Bottom-right exclusive Y coordinate of the rectangle

Returns

int Number of bytes used in TMEM for this texture

See also

rdpq_tex_upload

surface_make_sub

rdpq_tex_upload()

int rdpq_tex_upload	(	rdpq_tile_t	tile,
		const surface_t *	tex,
		const rdpq_texparms_t *	parms
	)

Load a texture into TMEM.

This function helps loading a texture into TMEM, which normally involves:

• Configuring a tile descriptor (via rdpq_set_tile)
• Setting the source texture image (via rdpq_set_texture_image)
• Loading the texture (via rdpq_load_tile or rdpq_load_block)

After calling this function, the specified tile descriptor will be ready to be used in drawing primitives like rdpq_triangle or rdpq_texture_rectangle.

If the texture uses a palette (FMT_CI8 or FMT_CI4), the tile descriptor will be by default pointing to palette 0. In the case of FMT_CI4, this might not be the correct palette; to specify a different palette number, add .palette = X to the tex parms. Before drawing a texture with palette, remember to call rdpq_mode_tlut to activate palette mode.

If you want to load a portion of a texture rather than the full texture, use rdpq_tex_upload_sub, or alternatively create a sub-surface using surface_make_sub and pass it to rdpq_tex_upload. See rdpq_tex_upload_sub for an example of both techniques.

Parameters

tile	Tile descriptor that will be initialized with this texture
tex	Surface containing the texture to load
parms	All optional parameters on where to load the texture and how to sample it. Refer to rdpq_texparms_t for more information.

Returns

Number of bytes used in TMEM for this texture

See also

rdpq_tex_upload_sub

surface_make_sub

rdpq_tex_reuse_sub()

int rdpq_tex_reuse_sub	(	rdpq_tile_t	tile,
		const rdpq_texparms_t *	parms,
		int	s0,
		int	t0,
		int	s1,
		int	t1
	)

Reuse a portion of the previously uploaded texture to TMEM.

When a texture has been uploaded, its possible to reuse it for multiple tiles without increasing TMEM usage. This function provides a way to achieve this while also configuring your own texture parameters for the reused texture.

This sub-variant also allows to specify what part of the uploaded texture must be reused. For example, after uploading a 64x64 texture (or a 64x64 sub texture of a larger surface), you can reuse an existing portion of it, like (16,16)-(48,48) or (0,0)-(8,32). Restrictions of rdpq_texparms_t apply just when reusing just as well as for uploading a texture.

Sub-rectangle must be within the bounds of the texture reused and be 8-byte aligned, not all starting positions are valid for different formats.

Starting horizontal position s0 must be 8-byte aligned, meaning for different image formats you can use TEX_FORMAT_BYTES2PIX(fmt, bytes) with bytes being in multiples of 8. Starting vertical position t0 must be in multiples of 2 pixels due to TMEM arrangement.

Leaving parms to NULL will copy the previous' texture texparms. Note: This function must be executed in a multi-upload block right after the reused texture has been uploaded.

Parameters

tile	Tile descriptor that will be initialized with reused texture
parms	All optional parameters on how to sample reused texture. Refer to rdpq_texparms_t for more information.
s0	Top-left X coordinate of the rectangle to reuse
t0	Top-left Y coordinate of the rectangle to reuse
s1	Bottom-right exclusive X coordinate of the rectangle
t1	Bottom-right exclusive Y coordinate of the rectangle

Returns

int Number of bytes used in TMEM for this texture (always 0)

rdpq_tex_reuse()

int rdpq_tex_reuse	(	rdpq_tile_t	tile,
		const rdpq_texparms_t *	parms
	)

Reuse the previously uploaded texture to TMEM.

When a texture has been uploaded, its possible to reuse it for multiple tiles without increasing TMEM usage. This function provides a way to achieve this while also configuring your own texture parameters for the reused texture.

This full-variant will use the whole texture that was previously uploaded. Leaving parms to NULL will copy the previous' texture texparms.

Note: This function must be executed in a multi-upload block right after the reused texture has been uploaded.

Parameters

tile	Tile descriptor that will be initialized with reused texture
parms	All optional parameters on how to sample reused texture. Refer to rdpq_texparms_t for more information.

Returns

int Number of bytes used in TMEM for this texture (always 0)

rdpq_tex_blit()

void rdpq_tex_blit	(	const surface_t *	surf,
		float	x0,
		float	y0,
		const rdpq_blitparms_t *	parms
	)

Blit a surface to the active framebuffer.

This is the highest level function for drawing an arbitrary-sized surface to the screen, possibly scaling and rotating it.

It handles all the required steps to blit the entire contents of a surface to the framebuffer, that is:

• Logically split the surface in chunks that fit the TMEM
• Calculate an appropriate scaling factor for each chunk
• Load each chunk into TMEM (via rdpq_tex_upload)
• Draw each chunk to the framebuffer (via rdpq_texture_rectangle or rdpq_triangle)

Note that this function only performs the actual blits, it does not configure the rendering mode or handle palettes. Before calling this function, make sure to configure the render mode via rdpq_set_mode_standard (or rdpq_set_mode_copy if no scaling and pixel format conversion is required). If the surface uses a palette, you also need to load the palette using rdpq_tex_upload_tlut.

This function is able to perform many different complex transformations. The implementation has been tuned to try to be as fast as possible for simple blits, but it scales up nicely for more complex operations.

The parameters that describe the transformations to perform are passed in the parms structure. The structure contains a lot of fields, but it has been designed so that most of them can be simply initalized to zero to disable advanced behaviors (and thus simply left unmentioned in an inline initialization).

For instance, this blits a large image to the screen, aligning it to the top-left corner (eg: a splashscreen).

rdpq_tex_blit(splashscreen, 0, 0, NULL);

This is the same, but the image will be centered on the screen. To do this, we specify the center of the screen as position, and then we set the hotspost of the image ("cx" and "cy" fields) to its center:

rdpq_tex_blit(splashscreen, 320/2, 160/2, &(rdpq_blitparms_t){
    .cx = splashscreen->width / 2,
    .cy = splashscreen->height / 2,
});

This examples scales a 64x64 image to 256x256, putting its center near the top-left of the screen (so part of resulting image will be offscreen):

rdpq_tex_blit(splashscreen, 20, 20, &(rdpq_blitparms_t){
    .cx = splashscreen->width / 2, .cy = splashscreen->height / 2,
    .scale_x = 4.0f, .scale_y = 4.0f,
});

This example assumes that the surface is a spritemap with frames of size 32x32. It selects the sprite at row 4, column 2, and draws it centered at position 100,100 on the screen applying a rotation of 45 degrees around its center:

rdpq_tex_blit(splashscreen, 100, 100, &(rdpq_blitparms_t){
     .s0 = 32*2, .t0 = 32*4,
     .width = 32, .height = 32,
     .cx = 16, .cy = 16,
     .theta = M_PI/4,
});

Parameters

surf	Surface to draw
x0	X coordinate on the framebuffer where to draw the surface
y0	Y coordinate on the framebuffer where to draw the surface
parms	Parameters for the blit operation (or NULL for default)

rdpq_tex_upload_tlut()

void rdpq_tex_upload_tlut	(	uint16_t *	tlut,
		int	color_idx,
		int	num_colors
	)

Load one or more palettes into TMEM.

This function allows to load one or more palettes into TMEM.

When using palettes, the upper half of TMEM is allocated to them. There is room for 256 colors in total, which allows for one palette for a CI8 texture, or up to 16 palettes for CI4 textures.

Parameters

tlut	Pointer to the color entries to load
color_idx	First color entry in TMEM that will be written to (0-255)
num_colors	Number of color entries to load (1-256)

rdpq_tex_multi_begin()

void rdpq_tex_multi_begin

(

void

)

Begin a multi-texture upload.

This function begins a multi-texture upload, with automatic TMEM layout. There are two main cases where you may want to squeeze multiple textures within TMEM: when loading mipmaps, and when using multi-texturing.

After calling rdpq_tex_multi_begin, you can call rdpq_tex_upload multiple times in sequence, without manually specifying a TMEM address. The functions will start filling TMEM from the beginning, in sequence.

If the TMEM becomes full and is unable to fullfil a load, an assertion will be issued.

Note

When calling rdpq_tex_upload or rdpq_tex_upload_sub in this mode, do not specify a TMEM address in the parms structure, as the actual address is automatically calculated.

See also

rdpq_tex_upload

rdpq_tex_upload_sub

rdpq_tex_multi_end

rdpq_tex_multi_end()

int rdpq_tex_multi_end

(

void

)

Finish a multi-texture upload.

This function finishes a multi-texture upload. See rdpq_tex_multi_begin for more information.

Returns

The number of bytes used in TMEM for this multi-texture upload

See also

rdpq_tex_multi_begin.