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qemu/hw/display/vga-helpers.h
Paolo Bonzini 973a724eb0 vga: implement horizontal pel panning in graphics modes 
This implements smooth scrolling, as used for example by Commander Keen
and Second Reality.

Unfortunately, this is not enough to avoid tearing in Commander Keen,
because sometimes the wrong start address is used for a frame.
On real EGA, the panning register is sampled on every line, while
the display start is latched for the next frame at the start of the
vertical retrace.  On real VGA, the panning register is also latched,
but at the end of the vertical retrace.  It looks like Keen exploits
this by only waiting for horizontal retrace when setting the display
start, but implementing it breaks the 256-color Keen games...

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-01-18 10:43:13 +01:00

476 lines
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/*
* QEMU VGA Emulator templates
*
* Copyright (c) 2003 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
static inline void vga_draw_glyph_line(uint8_t *d, uint32_t font_data,
uint32_t xorcol, uint32_t bgcol)
{
((uint32_t *)d)[0] = (-((font_data >> 7)) & xorcol) ^ bgcol;
((uint32_t *)d)[1] = (-((font_data >> 6) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[2] = (-((font_data >> 5) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[3] = (-((font_data >> 4) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[4] = (-((font_data >> 3) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[5] = (-((font_data >> 2) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[6] = (-((font_data >> 1) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[7] = (-((font_data >> 0) & 1) & xorcol) ^ bgcol;
}
static void vga_draw_glyph8(uint8_t *d, int linesize,
const uint8_t *font_ptr, int h,
uint32_t fgcol, uint32_t bgcol)
{
uint32_t font_data, xorcol;
xorcol = bgcol ^ fgcol;
do {
font_data = font_ptr[0];
vga_draw_glyph_line(d, font_data, xorcol, bgcol);
font_ptr += 4;
d += linesize;
} while (--h);
}
static void vga_draw_glyph16(uint8_t *d, int linesize,
const uint8_t *font_ptr, int h,
uint32_t fgcol, uint32_t bgcol)
{
uint32_t font_data, xorcol;
xorcol = bgcol ^ fgcol;
do {
font_data = font_ptr[0];
vga_draw_glyph_line(d, expand4to8[font_data >> 4],
xorcol, bgcol);
vga_draw_glyph_line(d + 32, expand4to8[font_data & 0x0f],
xorcol, bgcol);
font_ptr += 4;
d += linesize;
} while (--h);
}
static void vga_draw_glyph9(uint8_t *d, int linesize,
const uint8_t *font_ptr, int h,
uint32_t fgcol, uint32_t bgcol, int dup9)
{
uint32_t font_data, xorcol, v;
xorcol = bgcol ^ fgcol;
do {
font_data = font_ptr[0];
((uint32_t *)d)[0] = (-((font_data >> 7)) & xorcol) ^ bgcol;
((uint32_t *)d)[1] = (-((font_data >> 6) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[2] = (-((font_data >> 5) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[3] = (-((font_data >> 4) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[4] = (-((font_data >> 3) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[5] = (-((font_data >> 2) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[6] = (-((font_data >> 1) & 1) & xorcol) ^ bgcol;
v = (-((font_data >> 0) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[7] = v;
if (dup9)
((uint32_t *)d)[8] = v;
else
((uint32_t *)d)[8] = bgcol;
font_ptr += 4;
d += linesize;
} while (--h);
}
/*
* 4 color mode
*/
static void *vga_draw_line2(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width, int hpel)
{
uint32_t plane_mask, *palette, data, v;
int x;
palette = vga->last_palette;
plane_mask = mask16[vga->ar[VGA_ATC_PLANE_ENABLE] & 0xf];
hpel &= 7;
if (hpel) {
width += 8;
d = vga->panning_buf;
}
width >>= 3;
for(x = 0; x < width; x++) {
data = vga_read_dword_le(vga, addr & (VGA_VRAM_SIZE - 1));
data &= plane_mask;
v = expand2[GET_PLANE(data, 0)];
v |= expand2[GET_PLANE(data, 2)] << 2;
((uint32_t *)d)[0] = palette[v >> 12];
((uint32_t *)d)[1] = palette[(v >> 8) & 0xf];
((uint32_t *)d)[2] = palette[(v >> 4) & 0xf];
((uint32_t *)d)[3] = palette[(v >> 0) & 0xf];
v = expand2[GET_PLANE(data, 1)];
v |= expand2[GET_PLANE(data, 3)] << 2;
((uint32_t *)d)[4] = palette[v >> 12];
((uint32_t *)d)[5] = palette[(v >> 8) & 0xf];
((uint32_t *)d)[6] = palette[(v >> 4) & 0xf];
((uint32_t *)d)[7] = palette[(v >> 0) & 0xf];
d += 32;
addr += 4;
}
return hpel ? vga->panning_buf + 4 * hpel : NULL;
}
#define PUT_PIXEL2(d, n, v) \
((uint32_t *)d)[2*(n)] = ((uint32_t *)d)[2*(n)+1] = (v)
/*
* 4 color mode, dup2 horizontal
*/
static void *vga_draw_line2d2(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width, int hpel)
{
uint32_t plane_mask, *palette, data, v;
int x;
palette = vga->last_palette;
plane_mask = mask16[vga->ar[VGA_ATC_PLANE_ENABLE] & 0xf];
hpel &= 7;
if (hpel) {
width += 8;
d = vga->panning_buf;
}
width >>= 3;
for(x = 0; x < width; x++) {
data = vga_read_dword_le(vga, addr & (VGA_VRAM_SIZE - 1));
data &= plane_mask;
v = expand2[GET_PLANE(data, 0)];
v |= expand2[GET_PLANE(data, 2)] << 2;
PUT_PIXEL2(d, 0, palette[v >> 12]);
PUT_PIXEL2(d, 1, palette[(v >> 8) & 0xf]);
PUT_PIXEL2(d, 2, palette[(v >> 4) & 0xf]);
PUT_PIXEL2(d, 3, palette[(v >> 0) & 0xf]);
v = expand2[GET_PLANE(data, 1)];
v |= expand2[GET_PLANE(data, 3)] << 2;
PUT_PIXEL2(d, 4, palette[v >> 12]);
PUT_PIXEL2(d, 5, palette[(v >> 8) & 0xf]);
PUT_PIXEL2(d, 6, palette[(v >> 4) & 0xf]);
PUT_PIXEL2(d, 7, palette[(v >> 0) & 0xf]);
d += 64;
addr += 4;
}
return hpel ? vga->panning_buf + 8 * hpel : NULL;
}
/*
* 16 color mode
*/
static void *vga_draw_line4(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width, int hpel)
{
uint32_t plane_mask, data, v, *palette;
int x;
palette = vga->last_palette;
plane_mask = mask16[vga->ar[VGA_ATC_PLANE_ENABLE] & 0xf];
hpel &= 7;
if (hpel) {
width += 8;
d = vga->panning_buf;
}
width >>= 3;
for(x = 0; x < width; x++) {
data = vga_read_dword_le(vga, addr & (VGA_VRAM_SIZE - 1));
data &= plane_mask;
v = expand4[GET_PLANE(data, 0)];
v |= expand4[GET_PLANE(data, 1)] << 1;
v |= expand4[GET_PLANE(data, 2)] << 2;
v |= expand4[GET_PLANE(data, 3)] << 3;
((uint32_t *)d)[0] = palette[v >> 28];
((uint32_t *)d)[1] = palette[(v >> 24) & 0xf];
((uint32_t *)d)[2] = palette[(v >> 20) & 0xf];
((uint32_t *)d)[3] = palette[(v >> 16) & 0xf];
((uint32_t *)d)[4] = palette[(v >> 12) & 0xf];
((uint32_t *)d)[5] = palette[(v >> 8) & 0xf];
((uint32_t *)d)[6] = palette[(v >> 4) & 0xf];
((uint32_t *)d)[7] = palette[(v >> 0) & 0xf];
d += 32;
addr += 4;
}
return hpel ? vga->panning_buf + 4 * hpel : NULL;
}
/*
* 16 color mode, dup2 horizontal
*/
static void *vga_draw_line4d2(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width, int hpel)
{
uint32_t plane_mask, data, v, *palette;
int x;
palette = vga->last_palette;
plane_mask = mask16[vga->ar[VGA_ATC_PLANE_ENABLE] & 0xf];
hpel &= 7;
if (hpel) {
width += 8;
d = vga->panning_buf;
}
width >>= 3;
for(x = 0; x < width; x++) {
data = vga_read_dword_le(vga, addr & (VGA_VRAM_SIZE - 1));
data &= plane_mask;
v = expand4[GET_PLANE(data, 0)];
v |= expand4[GET_PLANE(data, 1)] << 1;
v |= expand4[GET_PLANE(data, 2)] << 2;
v |= expand4[GET_PLANE(data, 3)] << 3;
PUT_PIXEL2(d, 0, palette[v >> 28]);
PUT_PIXEL2(d, 1, palette[(v >> 24) & 0xf]);
PUT_PIXEL2(d, 2, palette[(v >> 20) & 0xf]);
PUT_PIXEL2(d, 3, palette[(v >> 16) & 0xf]);
PUT_PIXEL2(d, 4, palette[(v >> 12) & 0xf]);
PUT_PIXEL2(d, 5, palette[(v >> 8) & 0xf]);
PUT_PIXEL2(d, 6, palette[(v >> 4) & 0xf]);
PUT_PIXEL2(d, 7, palette[(v >> 0) & 0xf]);
d += 64;
addr += 4;
}
return hpel ? vga->panning_buf + 8 * hpel : NULL;
}
/*
* 256 color mode, double pixels
*
* XXX: add plane_mask support (never used in standard VGA modes)
*/
static void *vga_draw_line8d2(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width, int hpel)
{
uint32_t *palette;
int x;
palette = vga->last_palette;
hpel = (hpel >> 1) & 3;
if (hpel) {
width += 8;
d = vga->panning_buf;
}
width >>= 3;
for(x = 0; x < width; x++) {
addr &= VGA_VRAM_SIZE - 1;
PUT_PIXEL2(d, 0, palette[vga_read_byte(vga, addr + 0)]);
PUT_PIXEL2(d, 1, palette[vga_read_byte(vga, addr + 1)]);
PUT_PIXEL2(d, 2, palette[vga_read_byte(vga, addr + 2)]);
PUT_PIXEL2(d, 3, palette[vga_read_byte(vga, addr + 3)]);
d += 32;
addr += 4;
}
return hpel ? vga->panning_buf + 8 * hpel : NULL;
}
/*
* standard 256 color mode
*
* XXX: add plane_mask support (never used in standard VGA modes)
*/
static void *vga_draw_line8(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width, int hpel)
{
uint32_t *palette;
int x;
palette = vga->last_palette;
hpel = (hpel >> 1) & 3;
if (hpel) {
width += 8;
d = vga->panning_buf;
}
width >>= 3;
for(x = 0; x < width; x++) {
((uint32_t *)d)[0] = palette[vga_read_byte(vga, addr + 0)];
((uint32_t *)d)[1] = palette[vga_read_byte(vga, addr + 1)];
((uint32_t *)d)[2] = palette[vga_read_byte(vga, addr + 2)];
((uint32_t *)d)[3] = palette[vga_read_byte(vga, addr + 3)];
((uint32_t *)d)[4] = palette[vga_read_byte(vga, addr + 4)];
((uint32_t *)d)[5] = palette[vga_read_byte(vga, addr + 5)];
((uint32_t *)d)[6] = palette[vga_read_byte(vga, addr + 6)];
((uint32_t *)d)[7] = palette[vga_read_byte(vga, addr + 7)];
d += 32;
addr += 8;
}
return hpel ? vga->panning_buf + 4 * hpel : NULL;
}
/*
* 15 bit color
*/
static void *vga_draw_line15_le(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width, int hpel)
{
int w;
uint32_t v, r, g, b;
w = width;
do {
v = vga_read_word_le(vga, addr);
r = (v >> 7) & 0xf8;
g = (v >> 2) & 0xf8;
b = (v << 3) & 0xf8;
((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
addr += 2;
d += 4;
} while (--w != 0);
return NULL;
}
static void *vga_draw_line15_be(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width, int hpel)
{
int w;
uint32_t v, r, g, b;
w = width;
do {
v = vga_read_word_be(vga, addr);
r = (v >> 7) & 0xf8;
g = (v >> 2) & 0xf8;
b = (v << 3) & 0xf8;
((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
addr += 2;
d += 4;
} while (--w != 0);
return NULL;
}
/*
* 16 bit color
*/
static void *vga_draw_line16_le(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width, int hpel)
{
int w;
uint32_t v, r, g, b;
w = width;
do {
v = vga_read_word_le(vga, addr);
r = (v >> 8) & 0xf8;
g = (v >> 3) & 0xfc;
b = (v << 3) & 0xf8;
((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
addr += 2;
d += 4;
} while (--w != 0);
return NULL;
}
static void *vga_draw_line16_be(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width, int hpel)
{
int w;
uint32_t v, r, g, b;
w = width;
do {
v = vga_read_word_be(vga, addr);
r = (v >> 8) & 0xf8;
g = (v >> 3) & 0xfc;
b = (v << 3) & 0xf8;
((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
addr += 2;
d += 4;
} while (--w != 0);
return NULL;
}
/*
* 24 bit color
*/
static void *vga_draw_line24_le(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width, int hpel)
{
int w;
uint32_t r, g, b;
w = width;
do {
b = vga_read_byte(vga, addr + 0);
g = vga_read_byte(vga, addr + 1);
r = vga_read_byte(vga, addr + 2);
((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
addr += 3;
d += 4;
} while (--w != 0);
return NULL;
}
static void *vga_draw_line24_be(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width, int hpel)
{
int w;
uint32_t r, g, b;
w = width;
do {
r = vga_read_byte(vga, addr + 0);
g = vga_read_byte(vga, addr + 1);
b = vga_read_byte(vga, addr + 2);
((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
addr += 3;
d += 4;
} while (--w != 0);
return NULL;
}
/*
* 32 bit color
*/
static void *vga_draw_line32_le(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width, int hpel)
{
int w;
uint32_t r, g, b;
w = width;
do {
b = vga_read_byte(vga, addr + 0);
g = vga_read_byte(vga, addr + 1);
r = vga_read_byte(vga, addr + 2);
((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
addr += 4;
d += 4;
} while (--w != 0);
return NULL;
}
static void *vga_draw_line32_be(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width, int hpel)
{
int w;
uint32_t r, g, b;
w = width;
do {
r = vga_read_byte(vga, addr + 1);
g = vga_read_byte(vga, addr + 2);
b = vga_read_byte(vga, addr + 3);
((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
addr += 4;
d += 4;
} while (--w != 0);
return NULL;
}
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