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xemu/hw/xbox/nv2a/nv2a_vsh.c

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/*
* QEMU Geforce NV2A vertex shader translation
*
* Copyright (c) 2014 Jannik Vogel
* Copyright (c) 2012 espes
*
* Based on:
* Cxbx, VertexShader.cpp
* Copyright (c) 2004 Aaron Robinson <caustik@caustik.com>
* Kingofc <kingofc@freenet.de>
* Dxbx, uPushBuffer.pas
* Copyright (c) 2007 Shadow_tj, PatrickvL
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 or
* (at your option) version 3 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include <assert.h>
#include "nv2a_shaders_common.h"
#include "nv2a_vsh.h"
#define VSH_D3DSCM_CORRECTION 96
typedef enum {
PARAM_UNKNOWN = 0,
PARAM_R,
PARAM_V,
PARAM_C
} VshParameterType;
typedef enum {
OUTPUT_C = 0,
OUTPUT_O
} VshOutputType;
typedef enum {
OMUX_MAC = 0,
OMUX_ILU
} VshOutputMux;
typedef enum {
ILU_NOP = 0,
ILU_MOV,
ILU_RCP,
ILU_RCC,
ILU_RSQ,
ILU_EXP,
ILU_LOG,
ILU_LIT
} VshILU;
typedef enum {
MAC_NOP,
MAC_MOV,
MAC_MUL,
MAC_ADD,
MAC_MAD,
MAC_DP3,
MAC_DPH,
MAC_DP4,
MAC_DST,
MAC_MIN,
MAC_MAX,
MAC_SLT,
MAC_SGE,
MAC_ARL
} VshMAC;
typedef enum {
SWIZZLE_X = 0,
SWIZZLE_Y,
SWIZZLE_Z,
SWIZZLE_W
} VshSwizzle;
typedef struct VshFieldMapping {
VshFieldName field_name;
uint8_t subtoken;
uint8_t start_bit;
uint8_t bit_length;
} VshFieldMapping;
static const VshFieldMapping field_mapping[] = {
// Field Name DWORD BitPos BitSize
{ FLD_ILU, 1, 25, 3 },
{ FLD_MAC, 1, 21, 4 },
{ FLD_CONST, 1, 13, 8 },
{ FLD_V, 1, 9, 4 },
// INPUT A
{ FLD_A_NEG, 1, 8, 1 },
{ FLD_A_SWZ_X, 1, 6, 2 },
{ FLD_A_SWZ_Y, 1, 4, 2 },
{ FLD_A_SWZ_Z, 1, 2, 2 },
{ FLD_A_SWZ_W, 1, 0, 2 },
{ FLD_A_R, 2, 28, 4 },
{ FLD_A_MUX, 2, 26, 2 },
// INPUT B
{ FLD_B_NEG, 2, 25, 1 },
{ FLD_B_SWZ_X, 2, 23, 2 },
{ FLD_B_SWZ_Y, 2, 21, 2 },
{ FLD_B_SWZ_Z, 2, 19, 2 },
{ FLD_B_SWZ_W, 2, 17, 2 },
{ FLD_B_R, 2, 13, 4 },
{ FLD_B_MUX, 2, 11, 2 },
// INPUT C
{ FLD_C_NEG, 2, 10, 1 },
{ FLD_C_SWZ_X, 2, 8, 2 },
{ FLD_C_SWZ_Y, 2, 6, 2 },
{ FLD_C_SWZ_Z, 2, 4, 2 },
{ FLD_C_SWZ_W, 2, 2, 2 },
{ FLD_C_R_HIGH, 2, 0, 2 },
{ FLD_C_R_LOW, 3, 30, 2 },
{ FLD_C_MUX, 3, 28, 2 },
// Output
{ FLD_OUT_MAC_MASK, 3, 24, 4 },
{ FLD_OUT_R, 3, 20, 4 },
{ FLD_OUT_ILU_MASK, 3, 16, 4 },
{ FLD_OUT_O_MASK, 3, 12, 4 },
{ FLD_OUT_ORB, 3, 11, 1 },
{ FLD_OUT_ADDRESS, 3, 3, 8 },
{ FLD_OUT_MUX, 3, 2, 1 },
// Other
{ FLD_A0X, 3, 1, 1 },
{ FLD_FINAL, 3, 0, 1 }
};
typedef struct VshOpcodeParams {
bool A;
bool B;
bool C;
} VshOpcodeParams;
static const VshOpcodeParams ilu_opcode_params[] = {
/* ILU OP ParamA ParamB ParamC */
/* ILU_NOP */ { false, false, false }, // Dxbx note : Unused
/* ILU_MOV */ { false, false, true },
/* ILU_RCP */ { false, false, true },
/* ILU_RCC */ { false, false, true },
/* ILU_RSQ */ { false, false, true },
/* ILU_EXP */ { false, false, true },
/* ILU_LOG */ { false, false, true },
/* ILU_LIT */ { false, false, true },
};
static const VshOpcodeParams mac_opcode_params[] = {
/* MAC OP ParamA ParamB ParamC */
/* MAC_NOP */ { false, false, false }, // Dxbx note : Unused
/* MAC_MOV */ { true, false, false },
/* MAC_MUL */ { true, true, false },
/* MAC_ADD */ { true, false, true },
/* MAC_MAD */ { true, true, true },
/* MAC_DP3 */ { true, true, false },
/* MAC_DPH */ { true, true, false },
/* MAC_DP4 */ { true, true, false },
/* MAC_DST */ { true, true, false },
/* MAC_MIN */ { true, true, false },
/* MAC_MAX */ { true, true, false },
/* MAC_SLT */ { true, true, false },
/* MAC_SGE */ { true, true, false },
/* MAC_ARL */ { true, false, false },
};
static const char* mask_str[] = {
// xyzw xyzw
",", // 0000 ____
",w", // 0001 ___w
",z", // 0010 __z_
",zw", // 0011 __zw
",y", // 0100 _y__
",yw", // 0101 _y_w
",yz", // 0110 _yz_
",yzw", // 0111 _yzw
",x", // 1000 x___
",xw", // 1001 x__w
",xz", // 1010 x_z_
",xzw", // 1011 x_zw
",xy", // 1100 xy__
",xyw", // 1101 xy_w
",xyz", // 1110 xyz_
",xyzw" // 1111 xyzw
};
/* Note: OpenGL seems to be case-sensitive, and requires upper-case opcodes! */
static const char* mac_opcode[] = {
"NOP",
"MOV",
"MUL",
"ADD",
"MAD",
"DP3",
"DPH",
"DP4",
"DST",
"MIN",
"MAX",
"SLT",
"SGE",
"ARL A0.x", // Dxbx note : Alias for "mov a0.x"
};
static const char* ilu_opcode[] = {
"NOP",
"MOV",
"RCP",
"RCC",
"RSQ",
"EXP",
"LOG",
"LIT",
};
static bool ilu_force_scalar[] = {
false,
false,
true,
true,
true,
true,
true,
false,
};
static const char* out_reg_name[] = {
"oPos",
"???",
"???",
"oD0",
"oD1",
"oFog",
"oPts",
"oB0",
"oB1",
"oT0",
"oT1",
"oT2",
"oT3",
"???",
"???",
"A0.x",
};
// Retrieves a number of bits in the instruction token
static int vsh_get_from_token(const uint32_t *shader_token,
uint8_t subtoken,
uint8_t start_bit,
uint8_t bit_length)
{
return (shader_token[subtoken] >> start_bit) & ~(0xFFFFFFFF << bit_length);
}
uint8_t vsh_get_field(const uint32_t *shader_token, VshFieldName field_name)
{
return (uint8_t)(vsh_get_from_token(shader_token,
field_mapping[field_name].subtoken,
field_mapping[field_name].start_bit,
field_mapping[field_name].bit_length));
}
// Converts the C register address to disassembly format
static int16_t convert_c_register(const int16_t c_reg)
{
int16_t r = ((((c_reg >> 5) & 7) - 3) * 32) + (c_reg & 31);
r += VSH_D3DSCM_CORRECTION; /* to map -96..95 to 0..191 */
return r; //FIXME: = c_reg?!
}
static QString* decode_swizzle(const uint32_t *shader_token,
VshFieldName swizzle_field)
{
const char* swizzle_str = "xyzw";
VshSwizzle x, y, z, w;
/* some microcode instructions force a scalar value */
if (swizzle_field == FLD_C_SWZ_X
&& ilu_force_scalar[vsh_get_field(shader_token, FLD_ILU)]) {
x = y = z = w = vsh_get_field(shader_token, swizzle_field);
} else {
x = vsh_get_field(shader_token, swizzle_field++);
y = vsh_get_field(shader_token, swizzle_field++);
z = vsh_get_field(shader_token, swizzle_field++);
w = vsh_get_field(shader_token, swizzle_field);
}
if (x == SWIZZLE_X && y == SWIZZLE_Y
&& z == SWIZZLE_Z && w == SWIZZLE_W) {
/* Don't print the swizzle if it's .xyzw */
return qstring_from_str(""); // Will turn ".xyzw" into "."
/* Don't print duplicates */
} else if (x == y && y == z && z == w) {
return qstring_from_str((char[]){'.', swizzle_str[x], '\0'});
} else if (y == z && z == w) {
return qstring_from_str((char[]){'.',
swizzle_str[x], swizzle_str[y], '\0'});
} else if (z == w) {
return qstring_from_str((char[]){'.',
swizzle_str[x], swizzle_str[y], swizzle_str[z], '\0'});
} else {
return qstring_from_str((char[]){'.',
swizzle_str[x], swizzle_str[y],
swizzle_str[z], swizzle_str[w],
'\0'}); // Normal swizzle mask
}
}
static QString* decode_opcode_input(const uint32_t *shader_token,
VshParameterType param,
VshFieldName neg_field,
int reg_num)
{
/* This function decodes a vertex shader opcode parameter into a string.
* Input A, B or C is controlled via the Param and NEG fieldnames,
* the R-register address for each input is already given by caller. */
QString *ret_str = qstring_new();
if (vsh_get_field(shader_token, neg_field) > 0) {
qstring_append_chr(ret_str, '-');
}
/* PARAM_R uses the supplied reg_num, but the other two need to be
* determined */
char tmp[40];
switch (param) {
case PARAM_R:
snprintf(tmp, sizeof(tmp), "R%d", reg_num);
break;
case PARAM_V:
reg_num = vsh_get_field(shader_token, FLD_V);
snprintf(tmp, sizeof(tmp), "v%d", reg_num);
break;
case PARAM_C:
reg_num = convert_c_register(vsh_get_field(shader_token, FLD_CONST));
if (vsh_get_field(shader_token, FLD_A0X) > 0) {
//FIXME: does this really require the "correction" doe in convert_c_register?!
snprintf(tmp, sizeof(tmp), "c[A0+%d]", reg_num);
} else {
snprintf(tmp, sizeof(tmp), "c[%d]", reg_num);
}
break;
default:
fprintf(stderr, "Unknown vs param: 0x%x\n", param);
assert(false);
break;
}
qstring_append(ret_str, tmp);
{
/* swizzle bits are next to the neg bit */
QString *swizzle_str = decode_swizzle(shader_token, neg_field+1);
qstring_append(ret_str, qstring_get_str(swizzle_str));
QDECREF(swizzle_str);
}
return ret_str;
}
static QString* decode_opcode(const uint32_t *shader_token,
VshOutputMux out_mux,
uint32_t mask,
const char *opcode,
const char *inputs)
{
QString *ret = qstring_new();
int reg_num = vsh_get_field(shader_token, FLD_OUT_R);
/* Test for paired opcodes (in other words : Are both <> NOP?) */
if (out_mux == OMUX_MAC
&& vsh_get_field(shader_token, FLD_ILU) != ILU_NOP
&& reg_num == 1) {
/* Ignore paired MAC opcodes that write to R1 */
mask = 0;
} else if (out_mux == OMUX_ILU
&& vsh_get_field(shader_token, FLD_MAC) != MAC_NOP) {
/* Paired ILU opcodes can only write to R1 */
reg_num = 1;
}
if (strcmp(opcode, mac_opcode[MAC_ARL]) == 0) {
qstring_append_fmt(ret, " ARL(A0%s);\n", inputs);
} else if (mask > 0) {
qstring_append_fmt(ret, " %s(R%d%s%s);\n",
opcode, reg_num, mask_str[mask], inputs);
}
/* See if we must add a muxed opcode too: */
if (vsh_get_field(shader_token, FLD_OUT_MUX) == out_mux
/* Only if it's not masked away: */
&& vsh_get_field(shader_token, FLD_OUT_O_MASK) != 0) {
qstring_append(ret, " ");
qstring_append(ret, opcode);
qstring_append(ret, "(");
if (vsh_get_field(shader_token, FLD_OUT_ORB) == OUTPUT_C) {
/* TODO : Emulate writeable const registers */
qstring_append(ret, "c");
qstring_append_int(ret,
convert_c_register(
vsh_get_field(shader_token, FLD_OUT_ADDRESS)));
} else {
qstring_append(ret,
out_reg_name[
vsh_get_field(shader_token, FLD_OUT_ADDRESS) & 0xF]);
}
qstring_append(ret,
mask_str[
vsh_get_field(shader_token, FLD_OUT_O_MASK)]);
qstring_append(ret, inputs);
qstring_append(ret, ");\n");
}
return ret;
}
static QString* decode_token(const uint32_t *shader_token)
{
QString *ret;
/* Since it's potentially used twice, decode input C once: */
QString *input_c =
decode_opcode_input(shader_token,
vsh_get_field(shader_token, FLD_C_MUX),
FLD_C_NEG,
(vsh_get_field(shader_token, FLD_C_R_HIGH) << 2)
| vsh_get_field(shader_token, FLD_C_R_LOW));
/* See what MAC opcode is written to (if not masked away): */
VshMAC mac = vsh_get_field(shader_token, FLD_MAC);
if (mac != MAC_NOP) {
QString *inputs_mac = qstring_new();
if (mac_opcode_params[mac].A) {
QString *input_a =
decode_opcode_input(shader_token,
vsh_get_field(shader_token, FLD_A_MUX),
FLD_A_NEG,
vsh_get_field(shader_token, FLD_A_R));
qstring_append(inputs_mac, ", ");
qstring_append(inputs_mac, qstring_get_str(input_a));
QDECREF(input_a);
}
if (mac_opcode_params[mac].B) {
QString *input_b =
decode_opcode_input(shader_token,
vsh_get_field(shader_token, FLD_B_MUX),
FLD_B_NEG,
vsh_get_field(shader_token, FLD_B_R));
qstring_append(inputs_mac, ", ");
qstring_append(inputs_mac, qstring_get_str(input_b));
QDECREF(input_b);
}
if (mac_opcode_params[mac].C) {
qstring_append(inputs_mac, ", ");
qstring_append(inputs_mac, qstring_get_str(input_c));
}
/* Then prepend these inputs with the actual opcode, mask, and input : */
ret = decode_opcode(shader_token,
OMUX_MAC,
vsh_get_field(shader_token, FLD_OUT_MAC_MASK),
mac_opcode[mac],
qstring_get_str(inputs_mac));
QDECREF(inputs_mac);
} else {
ret = qstring_new();
}
/* See if a ILU opcode is present too: */
VshILU ilu = vsh_get_field(shader_token, FLD_ILU);
if (ilu != ILU_NOP) {
QString *inputs_c = qstring_from_str(", ");
qstring_append(inputs_c, qstring_get_str(input_c));
/* Append the ILU opcode, mask and (the already determined) input C: */
QString *ilu_op =
decode_opcode(shader_token,
OMUX_ILU,
vsh_get_field(shader_token, FLD_OUT_ILU_MASK),
ilu_opcode[ilu],
qstring_get_str(inputs_c));
qstring_append(ret, qstring_get_str(ilu_op));
QDECREF(inputs_c);
QDECREF(ilu_op);
}
QDECREF(input_c);
return ret;
}
static const char* vsh_header =
"\n"
"int A0 = 0;\n"
"\n"
"vec4 R0 = vec4(0.0,0.0,0.0,0.0);\n"
"vec4 R1 = vec4(0.0,0.0,0.0,0.0);\n"
"vec4 R2 = vec4(0.0,0.0,0.0,0.0);\n"
"vec4 R3 = vec4(0.0,0.0,0.0,0.0);\n"
"vec4 R4 = vec4(0.0,0.0,0.0,0.0);\n"
"vec4 R5 = vec4(0.0,0.0,0.0,0.0);\n"
"vec4 R6 = vec4(0.0,0.0,0.0,0.0);\n"
"vec4 R7 = vec4(0.0,0.0,0.0,0.0);\n"
"vec4 R8 = vec4(0.0,0.0,0.0,0.0);\n"
"vec4 R9 = vec4(0.0,0.0,0.0,0.0);\n"
"vec4 R10 = vec4(0.0,0.0,0.0,0.0);\n"
"vec4 R11 = vec4(0.0,0.0,0.0,0.0);\n"
"#define R12 oPos\n" /* R12 is a mirror of oPos */
"\n"
/* See:
* http://msdn.microsoft.com/en-us/library/windows/desktop/bb174703%28v=vs.85%29.aspx
* https://www.opengl.org/registry/specs/NV/vertex_program1_1.txt
*/
"\n"
//QQQ #ifdef NICE_CODE
"/* Converts the input to vec4, pads with last component */\n"
"vec4 _in(float v) { return vec4(v); }\n"
"vec4 _in(vec2 v) { return v.xyyy; }\n"
"vec4 _in(vec3 v) { return v.xyzz; }\n"
"vec4 _in(vec4 v) { return v.xyzw; }\n"
//#else
// "/* Make sure input is always a vec4 */\n"
// "#define _in(v) vec4(v)\n"
//#endif
"\n"
"#define INFINITY (1.0 / 0.0)\n"
"\n"
"#define MOV(dest, mask, src) dest.mask = _MOV(_in(src)).mask\n"
"vec4 _MOV(vec4 src)\n"
"{\n"
" return src;\n"
"}\n"
"\n"
"#define MUL(dest, mask, src0, src1) dest.mask = _MUL(_in(src0), _in(src1)).mask\n"
"vec4 _MUL(vec4 src0, vec4 src1)\n"
"{\n"
" return src0 * src1;\n"
"}\n"
"\n"
"#define ADD(dest, mask, src0, src1) dest.mask = _ADD(_in(src0), _in(src1)).mask\n"
"vec4 _ADD(vec4 src0, vec4 src1)\n"
"{\n"
" return src0 + src1;\n"
"}\n"
"\n"
"#define MAD(dest, mask, src0, src1, src2) dest.mask = _MAD(_in(src0), _in(src1), _in(src2)).mask\n"
"vec4 _MAD(vec4 src0, vec4 src1, vec4 src2)\n"
"{\n"
" return src0 * src1 + src2;\n"
"}\n"
"\n"
"#define DP3(dest, mask, src0, src1) dest.mask = _DP3(_in(src0), _in(src1)).mask\n"
"vec4 _DP3(vec4 src0, vec4 src1)\n"
"{\n"
" return vec4(dot(src0.xyz, src1.xyz));\n"
"}\n"
"\n"
"#define DPH(dest, mask, src0, src1) dest.mask = _DPH(_in(src0), _in(src1)).mask\n"
"vec4 _DPH(vec4 src0, vec4 src1)\n"
"{\n"
" return vec4(dot(vec4(src0.xyz, 1.0), src1));\n"
"}\n"
"\n"
"#define DP4(dest, mask, src0, src1) dest.mask = _DP4(_in(src0), _in(src1)).mask\n"
"vec4 _DP4(vec4 src0, vec4 src1)\n"
"{\n"
" return vec4(dot(src0, src1));\n"
"}\n"
"\n"
"#define DST(dest, mask, src0, src1) dest.mask = _DST(_in(src0), _in(src1)).mask\n"
"vec4 _DST(vec4 src0, vec4 src1)\n"
"{\n"
" return vec4(1.0,\n"
" src0.y * src1.y,\n"
" src0.z,\n"
" src1.w);\n"
"}\n"
"\n"
"#define MIN(dest, mask, src0, src1) dest.mask = _MIN(_in(src0), _in(src1)).mask\n"
"vec4 _MIN(vec4 src0, vec4 src1)\n"
"{\n"
" return min(src0, src1);\n"
"}\n"
"\n"
"#define MAX(dest, mask, src0, src1) dest.mask = _MAX(_in(src0), _in(src1)).mask\n"
"vec4 _MAX(vec4 src0, vec4 src1)\n"
"{\n"
" return max(src0, src1);\n"
"}\n"
"\n"
"#define SLT(dest, mask, src0, src1) dest.mask = _SLT(_in(src0), _in(src1)).mask\n"
"vec4 _SLT(vec4 src0, vec4 src1)\n"
"{\n"
" return vec4(lessThan(src0, src1));\n"
"}\n"
"\n"
"#define ARL(dest, src) dest = _ARL(_in(src).x)\n"
"int _ARL(float src)\n"
"{\n"
" /* Xbox GPU does specify rounding, OpenGL doesn't; so we need a bias.\n"
" * Example: We probably want to floor 16.99.. to 17, not 16.\n"
" * Source of error (why we get 16.99.. instead of 17.0) is typically\n"
" * vertex-attributes being normalized from a byte value to float:\n"
" * 17 / 255 = 0.06666.. so is this 0.06667 (ceil) or 0.06666 (floor)?\n"
" * Which value we get depends on the host GPU.\n"
" * If we multiply these rounded values by 255 later, we get:\n"
" * 17.00 (ARL result = 17) or 16.99 (ARL result = 16).\n"
" * We assume the intend was to get 17, so we add our bias to fix it. */\n"
" return int(floor(src + 0.001));\n"
"}\n"
"\n"
"#define SGE(dest, mask, src0, src1) dest.mask = _SGE(_in(src0), _in(src1)).mask\n"
"vec4 _SGE(vec4 src0, vec4 src1)\n"
"{\n"
" return vec4(greaterThanEqual(src0, src1));\n"
"}\n"
"\n"
"#define RCP(dest, mask, src) dest.mask = _RCP(_in(src).x).mask\n"
"vec4 _RCP(float src)\n"
"{\n"
" return vec4(1.0 / src);\n"
"}\n"
"\n"
"#define RCC(dest, mask, src) dest.mask = _RCC(_in(src).x).mask\n"
"vec4 _RCC(float src)\n"
"{\n"
" float t = 1.0 / src;\n"
" if (t > 0.0) {\n"
" t = clamp(t, 5.42101e-020, 1.884467e+019);\n"
" } else {\n"
" t = clamp(t, -1.884467e+019, -5.42101e-020);\n"
" }\n"
" return vec4(t);\n"
"}\n"
"\n"
"#define RSQ(dest, mask, src) dest.mask = _RSQ(_in(src).x).mask\n"
"vec4 _RSQ(float src)\n"
"{\n"
" if (src == 0.0) { return vec4(INFINITY); }\n"
" if (isinf(src)) { return vec4(0.0); }\n"
" return vec4(inversesqrt(abs(src)));\n"
"}\n"
"\n"
"#define EXP(dest, mask, src) dest.mask = _EXP(_in(src).x).mask\n"
"vec4 _EXP(float src)\n"
"{\n"
" vec4 result;\n"
" result.x = exp2(floor(src));\n"
" result.y = src - floor(src);\n"
" result.z = exp2(src);\n"
" result.w = 1.0;\n"
" return result;\n"
"}\n"
"\n"
"#define LOG(dest, mask, src) dest.mask = _LOG(_in(src).x).mask\n"
"vec4 _LOG(float src)\n"
"{\n"
" float tmp = abs(src);\n"
" if (tmp == 0.0) { return vec4(-INFINITY, 1.0f, -INFINITY, 1.0f); }\n"
" vec4 result;\n"
" result.x = floor(log2(tmp));\n"
" result.y = tmp / exp2(floor(log2(tmp)));\n"
" result.z = log2(tmp);\n"
" result.w = 1.0;\n"
" return result;\n"
"}\n"
"\n"
"#define LIT(dest, mask, src) dest.mask = _LIT(_in(src)).mask\n"
"vec4 _LIT(vec4 src)\n"
"{\n"
" vec4 s = src;\n"
" float epsilon = 1.0 / 256.0;\n"
" s.w = clamp(s.w, -(128.0 - epsilon), 128.0 - epsilon);\n"
" s.x = max(s.x, 0.0);\n"
" s.y = max(s.y, 0.0);\n"
" vec4 t = vec4(1.0, 0.0, 0.0, 1.0);\n"
" t.y = s.x;\n"
#if 1
" t.z = (s.x > 0.0) ? exp2(s.w * log2(s.y)) : 0.0;\n"
#else
" t.z = (s.x > 0.0) ? pow(s.y, s.w) : 0.0;\n"
#endif
" return t;\n"
"}\n";
void vsh_translate(uint16_t version,
const uint32_t *tokens,
unsigned int length,
bool z_perspective,
QString *header, QString *body)
{
qstring_append(header, vsh_header);
bool has_final = false;
int slot;
for (slot=0; slot < length; slot++) {
const uint32_t* cur_token = &tokens[slot * VSH_TOKEN_SIZE];
QString *token_str = decode_token(cur_token);
qstring_append_fmt(body,
" /* Slot %d: 0x%08X 0x%08X 0x%08X 0x%08X */",
slot,
cur_token[0],cur_token[1],cur_token[2],cur_token[3]);
qstring_append(body, "\n");
qstring_append(body, qstring_get_str(token_str));
qstring_append(body, "\n");
QDECREF(token_str);
if (vsh_get_field(cur_token, FLD_FINAL)) {
has_final = true;
break;
}
}
assert(has_final);
/* pre-divide and output the generated W so we can do persepctive correct
* interpolation manually. OpenGL can't, since we give it a W of 1 to work
* around the perspective divide */
qstring_append(body,
" if (oPos.w == 0.0 || isinf(oPos.w)) {\n"
" vtx.inv_w = 1.0;\n"
" } else {\n"
" vtx.inv_w = 1.0 / oPos.w;\n"
" }\n"
);
qstring_append(body,
/* the shaders leave the result in screen space, while
* opengl expects it in clip space.
* TODO: the pixel-center co-ordinate differences should handled
*/
" oPos.x = 2.0 * (oPos.x - surfaceSize.x * 0.5) / surfaceSize.x;\n"
" oPos.y = -2.0 * (oPos.y - surfaceSize.y * 0.5) / surfaceSize.y;\n"
);
if (z_perspective) {
qstring_append(body, " oPos.z = oPos.w;\n");
}
qstring_append(body,
/* Map the clip range into clip space so z is clipped correctly.
* Note this makes the values in the depth buffer wrong. This should be
* handled with gl_ClipDistance instead, but that has performance issues
* on OS X.
*/
" if (clipRange.y != clipRange.x) {\n"
" oPos.z = (oPos.z - 0.5 * (clipRange.x + clipRange.y)) / (0.5 * (clipRange.y - clipRange.x));\n"
" }\n"
/* Correct for the perspective divide */
" if (oPos.w < 0.0) {\n"
/* undo the perspective divide in the case where the point would be
* clipped so opengl can clip it correctly */
" oPos.xyz *= oPos.w;\n"
" } else {\n"
/* we don't want the OpenGL perspective divide to happen, but we
* can't multiply by W because it could be meaningless here */
" oPos.w = 1.0;\n"
" }\n"
);
}
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