src/mesa/main/scissor.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 #include "main/glheader.h"
  27 #include "main/context.h"
  28 #include "main/enums.h"
  29 #include "main/mtypes.h"
  30 #include "main/scissor.h"
  31
  32
  33 /**
  34  * Set scissor rectangle data directly in ScissorArray
  35  *
  36  * This is an internal function that performs no error checking on the
  37  * supplied data.  It also does \b not call \c dd_function_table::Scissor.
  38  *
  39  * \sa _mesa_set_scissor
  40  */
  41 static void
  42 set_scissor_no_notify(struct gl_context *ctx, unsigned idx,
  43                       GLint x, GLint y, GLsizei width, GLsizei height)
  44 {
  45    if (x == ctx->Scissor.ScissorArray[idx].X &&
  46        y == ctx->Scissor.ScissorArray[idx].Y &&
  47        width == ctx->Scissor.ScissorArray[idx].Width &&
  48        height == ctx->Scissor.ScissorArray[idx].Height)
  49       return;
  50
  51    FLUSH_VERTICES(ctx, _NEW_SCISSOR);
  52    ctx->Scissor.ScissorArray[idx].X = x;
  53    ctx->Scissor.ScissorArray[idx].Y = y;
  54    ctx->Scissor.ScissorArray[idx].Width = width;
  55    ctx->Scissor.ScissorArray[idx].Height = height;
  56 }
  57
  58 /**
  59  * Called via glScissor
  60  */
  61 void GLAPIENTRY
  62 _mesa_Scissor( GLint x, GLint y, GLsizei width, GLsizei height )
  63 {
  64    unsigned i;
  65    GET_CURRENT_CONTEXT(ctx);
  66
  67    if (MESA_VERBOSE & VERBOSE_API)
  68       _mesa_debug(ctx, "glScissor %d %d %d %d\n", x, y, width, height);
  69
  70    if (width < 0 || height < 0) {
  71       _mesa_error( ctx, GL_INVALID_VALUE, "glScissor" );
  72       return;
  73    }
  74
  75    /* The GL_ARB_viewport_array spec says:
  76     *
  77     *     "Scissor sets the scissor rectangle for all viewports to the same
  78     *     values and is equivalent (assuming no errors are generated) to:
  79     *
  80     *     for (uint i = 0; i < MAX_VIEWPORTS; i++) {
  81     *         ScissorIndexed(i, left, bottom, width, height);
  82     *     }"
  83     *
  84     * Set the scissor rectangle for all of the viewports supported by the
  85     * implementation, but only signal the driver once at the end.
  86     */
  87    for (i = 0; i < ctx->Const.MaxViewports; i++)
  88       set_scissor_no_notify(ctx, i, x, y, width, height);
  89
  90    if (ctx->Driver.Scissor)
  91       ctx->Driver.Scissor(ctx);
  92 }
  93
  94
  95 /**
  96  * Define the scissor box.
  97  *
  98  * \param x, y coordinates of the scissor box lower-left corner.
  99  * \param width width of the scissor box.
 100  * \param height height of the scissor box.
 101  *
 102  * \sa glScissor().
 103  *
 104  * Verifies the parameters and updates __struct gl_contextRec::Scissor. On a
 105  * change flushes the vertices and notifies the driver via
 106  * the dd_function_table::Scissor callback.
 107  */
 108 void
 109 _mesa_set_scissor(struct gl_context *ctx, unsigned idx,
 110                   GLint x, GLint y, GLsizei width, GLsizei height)
 111 {
 112    set_scissor_no_notify(ctx, idx, x, y, width, height);
 113
 114    if (ctx->Driver.Scissor)
 115       ctx->Driver.Scissor(ctx);
 116 }
 117
 118 /**
 119  * Define count scissor boxes starting at index.
 120  *
 121  * \param index  index of first scissor records to set
 122  * \param count  number of scissor records to set
 123  * \param x, y   pointer to array of struct gl_scissor_rects
 124  *
 125  * \sa glScissorArrayv().
 126  *
 127  * Verifies the parameters and call set_scissor_no_notify to do the work.
 128  */
 129 void GLAPIENTRY
 130 _mesa_ScissorArrayv(GLuint first, GLsizei count, const GLint *v)
 131 {
 132    int i;
 133    struct gl_scissor_rect *p = (struct gl_scissor_rect *) v;
 134    GET_CURRENT_CONTEXT(ctx);
 135
 136    if ((first + count) > ctx->Const.MaxViewports) {
 137       _mesa_error(ctx, GL_INVALID_VALUE,
 138                   "glScissorArrayv: first (%d) + count (%d) >= MaxViewports (%d)",
 139                   first, count, ctx->Const.MaxViewports);
 140       return;
 141    }
 142
 143    /* Verify width & height */
 144    for (i = 0; i < count; i++) {
 145       if (p[i].Width < 0 || p[i].Height < 0) {
 146          _mesa_error(ctx, GL_INVALID_VALUE,
 147                      "glScissorArrayv: index (%d) width or height < 0 (%d, %d)",
 148                      i, p[i].Width, p[i].Height);
 149          return;
 150       }
 151    }
 152
 153    for (i = 0; i < count; i++)
 154       set_scissor_no_notify(ctx, i + first,
 155                             p[i].X, p[i].Y, p[i].Width, p[i].Height);
 156
 157    if (ctx->Driver.Scissor)
 158       ctx->Driver.Scissor(ctx);
 159 }
 160
 161 /**
 162  * Define the scissor box.
 163  *
 164  * \param index  index of scissor records to set
 165  * \param x, y   coordinates of the scissor box lower-left corner.
 166  * \param width  width of the scissor box.
 167  * \param height height of the scissor box.
 168  *
 169  * Verifies the parameters call set_scissor_no_notify to do the work.
 170  */
 171 static void
 172 ScissorIndexed(GLuint index, GLint left, GLint bottom,
 173                GLsizei width, GLsizei height, const char *function)
 174 {
 175    GET_CURRENT_CONTEXT(ctx);
 176
 177    if (MESA_VERBOSE & VERBOSE_API)
 178       _mesa_debug(ctx, "%s(%d, %d, %d, %d, %d)\n",
 179                   function, index, left, bottom, width, height);
 180
 181    if (index >= ctx->Const.MaxViewports) {
 182       _mesa_error(ctx, GL_INVALID_VALUE,
 183                   "%s: index (%d) >= MaxViewports (%d)",
 184                   function, index, ctx->Const.MaxViewports);
 185       return;
 186    }
 187
 188    if (width < 0 || height < 0) {
 189       _mesa_error(ctx, GL_INVALID_VALUE,
 190                   "%s: index (%d) width or height < 0 (%d, %d)",
 191                   function, index, width, height);
 192       return;
 193    }
 194
 195    set_scissor_no_notify(ctx, index, left, bottom, width, height);
 196
 197    if (ctx->Driver.Scissor)
 198       ctx->Driver.Scissor(ctx);
 199 }
 200
 201 void GLAPIENTRY
 202 _mesa_ScissorIndexed(GLuint index, GLint left, GLint bottom,
 203                      GLsizei width, GLsizei height)
 204 {
 205    ScissorIndexed(index, left, bottom, width, height, "glScissorIndexed");
 206 }
 207
 208 void GLAPIENTRY
 209 _mesa_ScissorIndexedv(GLuint index, const GLint *v)
 210 {
 211    ScissorIndexed(index, v[0], v[1], v[2], v[3], "glScissorIndexedv");
 212 }
 213
 214 void GLAPIENTRY
 215 _mesa_WindowRectanglesEXT(GLenum mode, GLsizei count, const GLint *box)
 216 {
 217    int i;
 218    struct gl_scissor_rect newval[MAX_WINDOW_RECTANGLES];
 219    GET_CURRENT_CONTEXT(ctx);
 220
 221    if (MESA_VERBOSE & VERBOSE_API)
 222       _mesa_debug(ctx, "glWindowRectanglesEXT(%s, %d, %p)\n",
 223                   _mesa_enum_to_string(mode), count, box);
 224
 225    if (mode != GL_INCLUSIVE_EXT && mode != GL_EXCLUSIVE_EXT) {
 226       _mesa_error(ctx, GL_INVALID_ENUM,
 227                   "glWindowRectanglesEXT(invalid mode 0x%x)", mode);
 228       return;
 229    }
 230
 231    if (count < 0) {
 232       _mesa_error(ctx, GL_INVALID_VALUE, "glWindowRectanglesEXT(count < 0)");
 233       return;
 234    }
 235
 236    if (count > ctx->Const.MaxWindowRectangles) {
 237       _mesa_error(ctx, GL_INVALID_VALUE,
 238                   "glWindowRectanglesEXT(count >= MaxWindowRectangles (%d)",
 239                   ctx->Const.MaxWindowRectangles);
 240       return;
 241    }
 242
 243    for (i = 0; i < count; i++) {
 244       if (box[2] < 0 || box[3] < 0) {
 245          _mesa_error(ctx, GL_INVALID_VALUE,
 246                      "glWindowRectanglesEXT(box %d: w < 0 || h < 0)", i);
 247          return;
 248       }
 249       newval[i].X = box[0];
 250       newval[i].Y = box[1];
 251       newval[i].Width = box[2];
 252       newval[i].Height = box[3];
 253       box += 4;
 254    }
 255
 256    FLUSH_VERTICES(ctx, _NEW_SCISSOR);
 257    memcpy(ctx->Scissor.WindowRects, newval,
 258           sizeof(struct gl_scissor_rect) * count);
 259    ctx->Scissor.NumWindowRects = count;
 260    ctx->Scissor.WindowRectMode = mode;
 261
 262    if (ctx->Driver.Scissor)
 263       ctx->Driver.Scissor(ctx);
 264 }
 265
 266
 267 /**
 268  * Initialize the context's scissor state.
 269  * \param ctx  the GL context.
 270  */
 271 void
 272 _mesa_init_scissor(struct gl_context *ctx)
 273 {
 274    unsigned i;
 275
 276    /* Scissor group */
 277    ctx->Scissor.EnableFlags = 0;
 278    ctx->Scissor.WindowRectMode = GL_EXCLUSIVE_EXT;
 279
 280    /* Note: ctx->Const.MaxViewports may not have been set by the driver yet,
 281     * so just initialize all of them.
 282     */
 283    for (i = 0; i < MAX_VIEWPORTS; i++)
 284       set_scissor_no_notify(ctx, i, 0, 0, 0, 0);
 285 }