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+/**************************************************************************
+ *
+ * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * Copyright 2010 VMware, Inc.
+ * All Rights Reserved.
+ *
+ * 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, sub license, 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 (including the
+ * next paragraph) 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 NON-INFRINGEMENT.
+ * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS 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.
+ *
+ **************************************************************************/
+
+/**
+ * Polygon stipple helper module. Drivers/GPUs which don't support polygon
+ * stipple natively can use this module to simulate it.
+ *
+ * Basically, modify fragment shader to sample the 32x32 stipple pattern
+ * texture and do a fragment kill for the 'off' bits.
+ *
+ * This was originally a 'draw' module stage, but since we don't need
+ * vertex window coords or anything, it can be a stand-alone utility module.
+ *
+ * Authors: Brian Paul
+ */
+
+
+#include "pipe/p_context.h"
+#include "pipe/p_defines.h"
+#include "pipe/p_shader_tokens.h"
+#include "util/u_inlines.h"
+
+#include "util/u_format.h"
+#include "util/u_memory.h"
+#include "util/u_pstipple.h"
+#include "util/u_sampler.h"
+
+#include "tgsi/tgsi_transform.h"
+#include "tgsi/tgsi_dump.h"
+
+/** Approx number of new tokens for instructions in pstip_transform_inst() */
+#define NUM_NEW_TOKENS 50
+
+
+static void
+util_pstipple_update_stipple_texture(struct pipe_context *pipe,
+ struct pipe_resource *tex,
+ const uint32_t pattern[32])
+{
+ static const uint bit31 = 1 << 31;
+ struct pipe_transfer *transfer;
+ ubyte *data;
+ int i, j;
+
+ /* map texture memory */
+ transfer = pipe_get_transfer(pipe, tex, 0, 0,
+ PIPE_TRANSFER_WRITE, 0, 0, 32, 32);
+ data = pipe->transfer_map(pipe, transfer);
+
+ /*
+ * Load alpha texture.
+ * Note: 0 means keep the fragment, 255 means kill it.
+ * We'll negate the texel value and use KILP which kills if value
+ * is negative.
+ */
+ for (i = 0; i < 32; i++) {
+ for (j = 0; j < 32; j++) {
+ if (pattern[i] & (bit31 >> j)) {
+ /* fragment "on" */
+ data[i * transfer->stride + j] = 0;
+ }
+ else {
+ /* fragment "off" */
+ data[i * transfer->stride + j] = 255;
+ }
+ }
+ }
+
+ /* unmap */
+ pipe->transfer_unmap(pipe, transfer);
+ pipe->transfer_destroy(pipe, transfer);
+}
+
+
+/**
+ * Create a 32x32 alpha8 texture that encodes the given stipple pattern.
+ */
+struct pipe_resource *
+util_pstipple_create_stipple_texture(struct pipe_context *pipe,
+ const uint32_t pattern[32])
+{
+ struct pipe_screen *screen = pipe->screen;
+ struct pipe_resource templat, *tex;
+
+ memset(&templat, 0, sizeof(templat));
+ templat.target = PIPE_TEXTURE_2D;
+ templat.format = PIPE_FORMAT_A8_UNORM;
+ templat.last_level = 0;
+ templat.width0 = 32;
+ templat.height0 = 32;
+ templat.depth0 = 1;
+ templat.array_size = 1;
+ templat.bind = PIPE_BIND_SAMPLER_VIEW;
+
+ tex = screen->resource_create(screen, &templat);
+
+ if (tex)
+ util_pstipple_update_stipple_texture(pipe, tex, pattern);
+
+ return tex;
+}
+
+
+/**
+ * Create sampler view to sample the stipple texture.
+ */
+struct pipe_sampler_view *
+util_pstipple_create_sampler_view(struct pipe_context *pipe,
+ struct pipe_resource *tex)
+{
+ struct pipe_sampler_view templat, *sv;
+
+ u_sampler_view_default_template(&templat, tex, tex->format);
+ sv = pipe->create_sampler_view(pipe, tex, &templat);
+
+ return sv;
+}
+
+
+/**
+ * Create the sampler CSO that'll be used for stippling.
+ */
+void *
+util_pstipple_create_sampler(struct pipe_context *pipe)
+{
+ struct pipe_sampler_state templat;
+ void *s;
+
+ memset(&templat, 0, sizeof(templat));
+ templat.wrap_s = PIPE_TEX_WRAP_REPEAT;
+ templat.wrap_t = PIPE_TEX_WRAP_REPEAT;
+ templat.wrap_r = PIPE_TEX_WRAP_REPEAT;
+ templat.min_mip_filter = PIPE_TEX_MIPFILTER_NONE;
+ templat.min_img_filter = PIPE_TEX_FILTER_NEAREST;
+ templat.mag_img_filter = PIPE_TEX_FILTER_NEAREST;
+ templat.normalized_coords = 1;
+ templat.min_lod = 0.0f;
+ templat.max_lod = 0.0f;
+
+ s = pipe->create_sampler_state(pipe, &templat);
+ return s;
+}
+
+
+
+/**
+ * Subclass of tgsi_transform_context, used for transforming the
+ * user's fragment shader to add the extra texture sample and fragment kill
+ * instructions.
+ */
+struct pstip_transform_context {
+ struct tgsi_transform_context base;
+ uint tempsUsed; /**< bitmask */
+ int wincoordInput;
+ int maxInput;
+ uint samplersUsed; /**< bitfield of samplers used */
+ int freeSampler; /** an available sampler for the pstipple */
+ int texTemp; /**< temp registers */
+ int numImmed;
+ boolean firstInstruction;
+};
+
+
+/**
+ * TGSI declaration transform callback.
+ * Look for a free sampler, a free input attrib, and two free temp regs.
+ */
+static void
+pstip_transform_decl(struct tgsi_transform_context *ctx,
+ struct tgsi_full_declaration *decl)
+{
+ struct pstip_transform_context *pctx =
+ (struct pstip_transform_context *) ctx;
+
+ if (decl->Declaration.File == TGSI_FILE_SAMPLER) {
+ uint i;
+ for (i = decl->Range.First;
+ i <= decl->Range.Last; i++) {
+ pctx->samplersUsed |= 1 << i;
+ }
+ }
+ else if (decl->Declaration.File == TGSI_FILE_INPUT) {
+ pctx->maxInput = MAX2(pctx->maxInput, (int) decl->Range.Last);
+ if (decl->Semantic.Name == TGSI_SEMANTIC_POSITION)
+ pctx->wincoordInput = (int) decl->Range.First;
+ }
+ else if (decl->Declaration.File == TGSI_FILE_TEMPORARY) {
+ uint i;
+ for (i = decl->Range.First;
+ i <= decl->Range.Last; i++) {
+ pctx->tempsUsed |= (1 << i);
+ }
+ }
+
+ ctx->emit_declaration(ctx, decl);
+}
+
+
+static void
+pstip_transform_immed(struct tgsi_transform_context *ctx,
+ struct tgsi_full_immediate *immed)
+{
+ struct pstip_transform_context *pctx =
+ (struct pstip_transform_context *) ctx;
+ pctx->numImmed++;
+}
+
+
+/**
+ * Find the lowest zero bit in the given word, or -1 if bitfield is all ones.
+ */
+static int
+free_bit(uint bitfield)
+{
+ return ffs(~bitfield) - 1;
+}
+
+
+/**
+ * TGSI instruction transform callback.
+ * Replace writes to result.color w/ a temp reg.
+ * Upon END instruction, insert texture sampling code for antialiasing.
+ */
+static void
+pstip_transform_inst(struct tgsi_transform_context *ctx,
+ struct tgsi_full_instruction *inst)
+{
+ struct pstip_transform_context *pctx =
+ (struct pstip_transform_context *) ctx;
+
+ if (pctx->firstInstruction) {
+ /* emit our new declarations before the first instruction */
+
+ struct tgsi_full_declaration decl;
+ struct tgsi_full_instruction newInst;
+ uint i;
+ int wincoordInput;
+
+ /* find free sampler */
+ pctx->freeSampler = free_bit(pctx->samplersUsed);
+ if (pctx->freeSampler >= PIPE_MAX_SAMPLERS)
+ pctx->freeSampler = PIPE_MAX_SAMPLERS - 1;
+
+ if (pctx->wincoordInput < 0)
+ wincoordInput = pctx->maxInput + 1;
+ else
+ wincoordInput = pctx->wincoordInput;
+
+ /* find one free temp reg */
+ for (i = 0; i < 32; i++) {
+ if ((pctx->tempsUsed & (1 << i)) == 0) {
+ /* found a free temp */
+ if (pctx->texTemp < 0)
+ pctx->texTemp = i;
+ else
+ break;
+ }
+ }
+ assert(pctx->texTemp >= 0);
+
+ if (pctx->wincoordInput < 0) {
+ /* declare new position input reg */
+ decl = tgsi_default_full_declaration();
+ decl.Declaration.File = TGSI_FILE_INPUT;
+ decl.Declaration.Interpolate = TGSI_INTERPOLATE_LINEAR;
+ decl.Declaration.Semantic = 1;
+ decl.Semantic.Name = TGSI_SEMANTIC_POSITION;
+ decl.Semantic.Index = 0;
+ decl.Range.First =
+ decl.Range.Last = wincoordInput;
+ ctx->emit_declaration(ctx, &decl);
+ }
+
+ /* declare new sampler */
+ decl = tgsi_default_full_declaration();
+ decl.Declaration.File = TGSI_FILE_SAMPLER;
+ decl.Range.First =
+ decl.Range.Last = pctx->freeSampler;
+ ctx->emit_declaration(ctx, &decl);
+
+ /* declare new temp regs */
+ decl = tgsi_default_full_declaration();
+ decl.Declaration.File = TGSI_FILE_TEMPORARY;
+ decl.Range.First =
+ decl.Range.Last = pctx->texTemp;
+ ctx->emit_declaration(ctx, &decl);
+
+ /* emit immediate = {1/32, 1/32, 1, 1}
+ * The index/position of this immediate will be pctx->numImmed
+ */
+ {
+ static const float value[4] = { 1.0/32, 1.0/32, 1.0, 1.0 };
+ struct tgsi_full_immediate immed;
+ uint size = 4;
+ immed = tgsi_default_full_immediate();
+ immed.Immediate.NrTokens = 1 + size; /* one for the token itself */
+ immed.u[0].Float = value[0];
+ immed.u[1].Float = value[1];
+ immed.u[2].Float = value[2];
+ immed.u[3].Float = value[3];
+ ctx->emit_immediate(ctx, &immed);
+ }
+
+ pctx->firstInstruction = FALSE;
+
+
+ /*
+ * Insert new MUL/TEX/KILP instructions at start of program
+ * Take gl_FragCoord, divide by 32 (stipple size), sample the
+ * texture and kill fragment if needed.
+ *
+ * We'd like to use non-normalized texcoords to index into a RECT
+ * texture, but we can only use REPEAT wrap mode with normalized
+ * texcoords. Darn.
+ */
+
+ /* XXX invert wincoord if origin isn't lower-left... */
+
+ /* MUL texTemp, INPUT[wincoord], 1/32; */
+ newInst = tgsi_default_full_instruction();
+ newInst.Instruction.Opcode = TGSI_OPCODE_MUL;
+ newInst.Instruction.NumDstRegs = 1;
+ newInst.Dst[0].Register.File = TGSI_FILE_TEMPORARY;
+ newInst.Dst[0].Register.Index = pctx->texTemp;
+ newInst.Instruction.NumSrcRegs = 2;
+ newInst.Src[0].Register.File = TGSI_FILE_INPUT;
+ newInst.Src[0].Register.Index = wincoordInput;
+ newInst.Src[1].Register.File = TGSI_FILE_IMMEDIATE;
+ newInst.Src[1].Register.Index = pctx->numImmed;
+ ctx->emit_instruction(ctx, &newInst);
+
+ /* TEX texTemp, texTemp, sampler; */
+ newInst = tgsi_default_full_instruction();
+ newInst.Instruction.Opcode = TGSI_OPCODE_TEX;
+ newInst.Instruction.NumDstRegs = 1;
+ newInst.Dst[0].Register.File = TGSI_FILE_TEMPORARY;
+ newInst.Dst[0].Register.Index = pctx->texTemp;
+ newInst.Instruction.NumSrcRegs = 2;
+ newInst.Instruction.Texture = TRUE;
+ newInst.Texture.Texture = TGSI_TEXTURE_2D;
+ newInst.Src[0].Register.File = TGSI_FILE_TEMPORARY;
+ newInst.Src[0].Register.Index = pctx->texTemp;
+ newInst.Src[1].Register.File = TGSI_FILE_SAMPLER;
+ newInst.Src[1].Register.Index = pctx->freeSampler;
+ ctx->emit_instruction(ctx, &newInst);
+
+ /* KIL -texTemp; # if -texTemp < 0, KILL fragment */
+ newInst = tgsi_default_full_instruction();
+ newInst.Instruction.Opcode = TGSI_OPCODE_KIL;
+ newInst.Instruction.NumDstRegs = 0;
+ newInst.Instruction.NumSrcRegs = 1;
+ newInst.Src[0].Register.File = TGSI_FILE_TEMPORARY;
+ newInst.Src[0].Register.Index = pctx->texTemp;
+ newInst.Src[0].Register.Negate = 1;
+ ctx->emit_instruction(ctx, &newInst);
+ }
+
+ /* emit this instruction */
+ ctx->emit_instruction(ctx, inst);
+}
+
+
+/**
+ * Given a fragment shader, return a new fragment shader which
+ * samples a stipple texture and executes KILL.
+ */
+struct pipe_shader_state *
+util_pstipple_create_fragment_shader(struct pipe_context *pipe,
+ struct pipe_shader_state *fs,
+ unsigned *samplerUnitOut)
+{
+ struct pipe_shader_state *new_fs;
+ struct pstip_transform_context transform;
+ const uint newLen = tgsi_num_tokens(fs->tokens) + NUM_NEW_TOKENS;
+
+ new_fs = MALLOC(sizeof(*new_fs));
+ if (!new_fs)
+ return NULL;
+
+ new_fs->tokens = tgsi_alloc_tokens(newLen);
+ if (!new_fs->tokens) {
+ FREE(new_fs);
+ return NULL;
+ }
+
+ memset(&transform, 0, sizeof(transform));
+ transform.wincoordInput = -1;
+ transform.maxInput = -1;
+ transform.texTemp = -1;
+ transform.firstInstruction = TRUE;
+ transform.base.transform_instruction = pstip_transform_inst;
+ transform.base.transform_declaration = pstip_transform_decl;
+ transform.base.transform_immediate = pstip_transform_immed;
+
+ tgsi_transform_shader(fs->tokens,
+ (struct tgsi_token *) new_fs->tokens,
+ newLen, &transform.base);
+
+#if 0 /* DEBUG */
+ tgsi_dump(fs->tokens, 0);
+ tgsi_dump(pstip_fs.tokens, 0);
+#endif
+
+ assert(transform.freeSampler < PIPE_MAX_SAMPLERS);
+ *samplerUnitOut = transform.freeSampler;
+
+ return new_fs;
+}
+