blit.c

/*
	PSP VSH 24bpp text bliter
*/
#include <libk/stdarg.h>
#include <libk/stdio.h>
#include <libk/string.h>
#include "blit.h"

#define ALPHA_BLEND 1
#define printf ksceDebugPrintf

extern unsigned char msx[];
static int pwidth, pheight, pcenter, bufferwidth, pixelformat;
static unsigned int *vram32;

static uint32_t fcolor = COLOR_WHITE;
static uint32_t bcolor = COLOR_TRANSPARENT;

#if ALPHA_BLEND
static uint32_t adjust_alpha(uint32_t col) {
	uint32_t alpha = col>>24, c1, c2;
	uint8_t mul;

	if(alpha == 0 || alpha == 0xff)
		return col;

	mul = (uint8_t)(255-alpha);

	c1 = col & 0x00ff00ff;
	c1 = ((c1 * mul) >> 8) & 0x00ff00ff;

	c2 = col & 0x0000ff00;
	c2 = ((c2 * mul) >> 8) & 0x0000ff00;

	return (alpha<<24) | c1 | c2;
}
#endif

/////////////////////////////////////////////////////////////////////////////
// blit text
/////////////////////////////////////////////////////////////////////////////
void blit_set_color(int fg_col, int bg_col) {
	fcolor = fg_col;
	bcolor = bg_col;
}

/////////////////////////////////////////////////////////////////////////////
// blit text
/////////////////////////////////////////////////////////////////////////////
int blit_string(int sx, int sy, const char *msg) {
	uint32_t fg_col, bg_col;
	int x, y, p, offset;
	unsigned char font;
	char code;

#if ALPHA_BLEND
	uint32_t col, c1, c2, alpha;

	fg_col = adjust_alpha(fcolor);
	bg_col = adjust_alpha(bcolor);
#else
	fg_col = fcolor;
	bg_col = bcolor;
#endif

	if(bufferwidth == 0 || pixelformat != 0)
		return -1;

	for(x=0; msg[x] && x<(pwidth/16); ++x) {
		code = msg[x] & 0x7f; // 7bit ANK

		for(y=0; y<8; ++y) {
			offset = (sy + (y * 2)) * bufferwidth + sx + x * 16;
			font = y>=7 ? 0x00 : msx[ code*8 + y ];

			for(p=0; p<8; ++p) {
#if ALPHA_BLEND
				col = (font & 0x80) ? fg_col : bg_col;
				alpha = col>>24;

				if(alpha == 0) {
					ksceKernelMemcpyKernelToUser((uintptr_t)(&vram32[offset]), &col, sizeof(col));
					ksceKernelMemcpyKernelToUser((uintptr_t)(&vram32[offset + 1]), &col, sizeof(col));
					ksceKernelMemcpyKernelToUser((uintptr_t)(&vram32[offset + bufferwidth]), &col, sizeof(col));
					ksceKernelMemcpyKernelToUser((uintptr_t)(&vram32[offset + bufferwidth + 1]), &col, sizeof(col));

				} else if(alpha != 0xff) {
					ksceKernelMemcpyUserToKernel(&c2, (uintptr_t)(vram32[offset]), sizeof(unsigned int));
					c1 = c2 & 0x00ff00ff;
					c2 = c2 & 0x0000ff00;
					c1 = ((c1*alpha)>>8)&0x00ff00ff;
					c2 = ((c2*alpha)>>8)&0x0000ff00;
					uint32_t color = (col&0xffffff) + c1 + c2;
					ksceKernelMemcpyKernelToUser((uintptr_t)(vram32 + offset), &color, sizeof(uint32_t));
					ksceKernelMemcpyKernelToUser((uintptr_t)(vram32 + offset + 1), &color, sizeof(uint32_t));
					ksceKernelMemcpyKernelToUser((uintptr_t)(vram32 + offset + bufferwidth), &color, sizeof(uint32_t));
					ksceKernelMemcpyKernelToUser((uintptr_t)(vram32 + offset + bufferwidth + 1), &color, sizeof(uint32_t));
				}
#else
				uint32_t color = (font & 0x80) ? fg_col : bg_col;
				ksceKernelMemcpyKernelToUser((uintptr_t)(vram32 + offset + 1), &color, sizeof(uint32_t));
				ksceKernelMemcpyKernelToUser((uintptr_t)(vram32 + offset + bufferwidth), &color, sizeof(uint32_t));
				ksceKernelMemcpyKernelToUser((uintptr_t)(vram32 + offset + bufferwidth + 1), &color, sizeof(uint32_t));
#endif

				font <<= 1;
				offset += 2;
			}
		}
	}

	return x;
}

int blit_string_ctr(int sy, const char *msg) {
	int sx = pcenter - (strlen(msg) * 8);

	return blit_string(sx,sy,msg);
}

int blit_string_center_x(int offset) {
	return pcenter-(offset*8);
}

int blit_stringf(int sx, int sy, const char *msg, ...) {
	va_list list;
	char string[512];

	va_start(list, msg);
	vsnprintf(string, 512, msg, list);
	va_end(list);

	// correct value is (sx/960.0f)*pwidth but needs more adjustments
	return blit_string(sx, (sy/544.0f)*pheight, string);
}

int blit_set_frame_buf(const SceDisplayFrameBuf *param) {
	pwidth = param->width;
	pheight = param->height;
	pcenter = pwidth/2;
	vram32 = param->base;
	bufferwidth = param->pitch;
	pixelformat = param->pixelformat;

	if (bufferwidth == 0 || pixelformat != 0)
		return -1;

	fcolor = COLOR_WHITE;
	bcolor = COLOR_TRANSPARENT;

  return 0;
}