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[CHG] GRRLIB_Compose is now using 4 spaces for tabs (instead of 2)

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Crayon2000 2009-08-25 00:53:43 +00:00
parent 08c03a8de9
commit c8abda9052
1 changed files with 40 additions and 42 deletions
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82
GRRLIB/GRRLIB/GRRLIB_texEdit.c
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@ -173,9 +173,8 @@ GRRLIB_texImg* GRRLIB_LoadTextureJPG (const u8 *my_jpg) {
return my_texture; return my_texture;
} }
//==============================================================================
/** /**
* Compose a layer/sprite to a canvas/textured-image * Compose a layer/sprite to a canvas/textured-image.
* Currently only performs "a-over-b (normal) alpha compositing" (opacity) * Currently only performs "a-over-b (normal) alpha compositing" (opacity)
* Ie. Light source is behind the eye, not behind the canvas! * Ie. Light source is behind the eye, not behind the canvas!
* @author BlueChip * @author BlueChip
@ -185,55 +184,54 @@ GRRLIB_texImg* GRRLIB_LoadTextureJPG (const u8 *my_jpg) {
* @param canvas : The canvas/textured-image on which to draw * @param canvas : The canvas/textured-image on which to draw
* @param mode : Currently unused - will be composition mode * @param mode : Currently unused - will be composition mode
*/ */
//==============================================================================
void GRRLIB_Compose( int xoff, int yoff, GRRLIB_texImg* layer, void GRRLIB_Compose( int xoff, int yoff, GRRLIB_texImg* layer,
GRRLIB_texImg* canvas, GRRLIB_ComposeMode mode ) GRRLIB_texImg* canvas, GRRLIB_ComposeMode mode )
{ {
int x, y; // x & y on layer int x, y; // x & y on layer
int cnv_x, cnv_y; // x & y on canvas int cnv_x, cnv_y; // x & y on canvas
float cnv_a, lyr_a, alpha; // Alpha of canvas & layer & result float cnv_a, lyr_a, alpha; // Alpha of canvas & layer & result
u32 cnv_c, lyr_c; // Colour of pixel from canvas & layer u32 cnv_c, lyr_c; // Colour of pixel from canvas & layer
u32 new_r, new_g, new_b, new_a; // R, G, B & A values of result u32 new_r, new_g, new_b, new_a; // R, G, B & A values of result
// Loop through the layer, one pixel at a time // Loop through the layer, one pixel at a time
for (y = 0; y < layer->h; y++) { for (y = 0; y < layer->h; y++) {
cnv_y = y +yoff; // y coord of canvas pixel to be changed cnv_y = y + yoff; // y coord of canvas pixel to be changed
if (cnv_y < 0) continue ; // not on the canvas yet if (cnv_y < 0) continue ; // not on the canvas yet
if (cnv_y >= canvas->h) break; // off the bottom of the canvas if (cnv_y >= canvas->h) break; // off the bottom of the canvas
for (x = 0; x < layer->w; x++) { for (x = 0; x < layer->w; x++) {
cnv_x = x +xoff; // x coord of canvas pixel to be changed cnv_x = x + xoff; // x coord of canvas pixel to be changed
if (cnv_x < 0) continue ; // not on the canvas yet if (cnv_x < 0) continue ; // not on the canvas yet
if (cnv_x >= canvas->h) break; // off the right of the canvas if (cnv_x >= canvas->h) break; // off the right of the canvas
// Grab the working pixels from the canvas and layer // Grab the working pixels from the canvas and layer
cnv_c = GRRLIB_GetPixelFromtexImg(cnv_x,cnv_y, canvas); cnv_c = GRRLIB_GetPixelFromtexImg(cnv_x, cnv_y, canvas);
lyr_c = GRRLIB_GetPixelFromtexImg(x,y, layer); lyr_c = GRRLIB_GetPixelFromtexImg(x, y, layer);
// Calculate alpha value as 0.0 to 1.0 in 255th's // Calculate alpha value as 0.0 to 1.0 in 255th's
cnv_a = A(cnv_c) /255.0; cnv_a = A(cnv_c) /255.0;
lyr_a = A(lyr_c) /255.0; lyr_a = A(lyr_c) /255.0;
// Perform desired composition // Perform desired composition
switch (mode) { switch (mode) {
default: default:
case GRRLIB_COMPOSE_NORMAL : case GRRLIB_COMPOSE_NORMAL :
// Perform "a-over-b (normal) alpha compositing" (opacity) // Perform "a-over-b (normal) alpha compositing" (opacity)
// http://en.wikipedia.org/wiki/Alpha_compositing // http://en.wikipedia.org/wiki/Alpha_compositing
new_a = (u32)( A(lyr_c) + (A(cnv_c) *(1.0 -lyr_a)) ); new_a = (u32)( A(lyr_c) + (A(cnv_c) *(1.0 -lyr_a)) );
alpha = new_a /255.0; alpha = new_a /255.0;
new_r = ( (R(lyr_c) *lyr_a) + (R(cnv_c) *cnv_a *(1 -lyr_a)) ) /alpha; new_r = ( (R(lyr_c) *lyr_a) + (R(cnv_c) *cnv_a *(1 -lyr_a)) ) /alpha;
new_g = ( (G(lyr_c) *lyr_a) + (G(cnv_c) *cnv_a *(1 -lyr_a)) ) /alpha; new_g = ( (G(lyr_c) *lyr_a) + (G(cnv_c) *cnv_a *(1 -lyr_a)) ) /alpha;
new_b = ( (B(lyr_c) *lyr_a) + (B(cnv_c) *cnv_a *(1 -lyr_a)) ) /alpha; new_b = ( (B(lyr_c) *lyr_a) + (B(cnv_c) *cnv_a *(1 -lyr_a)) ) /alpha;
break; break;
} }
// Replace the old canvas pixel with the new one // Replace the old canvas pixel with the new one
GRRLIB_SetPixelTotexImg( cnv_x,cnv_y, canvas, GRRLIB_SetPixelTotexImg( cnv_x, cnv_y, canvas,
RGBA(new_r, new_g, new_b, new_a) ); RGBA(new_r, new_g, new_b, new_a) );
}//for x }//for x
}// for y }// for y
GRRLIB_FlushTex(canvas); GRRLIB_FlushTex(canvas);
} }