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/mtypes.h"
  29 #include "main/scissor.h"
  30
  31
  32 /**
  33  * Set scissor rectangle data directly in ScissorArray
  34  *
  35  * This is an internal function that performs no error checking on the
  36  * supplied data.  It also does \b not call \c dd_function_table::Scissor.
  37  *
  38  * \sa _mesa_set_scissor
  39  */
  40 static void
  41 set_scissor_no_notify(struct gl_context *ctx, unsigned idx,
  42                       GLint x, GLint y, GLsizei width, GLsizei height)
  43 {
  44    if (x == ctx->Scissor.ScissorArray[idx].X &&
  45        y == ctx->Scissor.ScissorArray[idx].Y &&
  46        width == ctx->Scissor.ScissorArray[idx].Width &&
  47        height == ctx->Scissor.ScissorArray[idx].Height)
  48       return;
  49
  50    FLUSH_VERTICES(ctx, _NEW_SCISSOR);
  51    ctx->Scissor.ScissorArray[idx].X = x;
  52    ctx->Scissor.ScissorArray[idx].Y = y;
  53    ctx->Scissor.ScissorArray[idx].Width = width;
  54    ctx->Scissor.ScissorArray[idx].Height = height;
  55 }
  56
  57 /**
  58  * Called via glScissor
  59  */
  60 void GLAPIENTRY
  61 _mesa_Scissor( GLint x, GLint y, GLsizei width, GLsizei height )
  62 {
  63    unsigned i;
  64    GET_CURRENT_CONTEXT(ctx);
  65
  66    if (MESA_VERBOSE & VERBOSE_API)
  67       _mesa_debug(ctx, "glScissor %d %d %d %d\n", x, y, width, height);
  68
  69    if (width < 0 || height < 0) {
  70       _mesa_error( ctx, GL_INVALID_VALUE, "glScissor" );
  71       return;
  72    }
  73
  74    /* The GL_ARB_viewport_array spec says:
  75     *
  76     *     "Scissor sets the scissor rectangle for all viewports to the same
  77     *     values and is equivalent (assuming no errors are generated) to:
  78     *
  79     *     for (uint i = 0; i < MAX_VIEWPORTS; i++) {
  80     *         ScissorIndexed(i, left, bottom, width, height);
  81     *     }"
  82     *
  83     * Set the scissor rectangle for all of the viewports supported by the
  84     * implementation, but only signal the driver once at the end.
  85     */
  86    for (i = 0; i < ctx->Const.MaxViewports; i++)
  87       set_scissor_no_notify(ctx, i, x, y, width, height);
  88
  89    if (ctx->Driver.Scissor)
  90       ctx->Driver.Scissor(ctx);
  91 }
  92
  93
  94 /**
  95  * Define the scissor box.
  96  *
  97  * \param x, y coordinates of the scissor box lower-left corner.
  98  * \param width width of the scissor box.
  99  * \param height height of the scissor box.
 100  *
 101  * \sa glScissor().
 102  *
 103  * Verifies the parameters and updates __struct gl_contextRec::Scissor. On a
 104  * change flushes the vertices and notifies the driver via
 105  * the dd_function_table::Scissor callback.
 106  */
 107 void
 108 _mesa_set_scissor(struct gl_context *ctx, unsigned idx,
 109                   GLint x, GLint y, GLsizei width, GLsizei height)
 110 {
 111    set_scissor_no_notify(ctx, idx, x, y, width, height);
 112
 113    if (ctx->Driver.Scissor)
 114       ctx->Driver.Scissor(ctx);
 115 }
 116
 117 /**
 118  * Define count scissor boxes starting at index.
 119  *
 120  * \param index  index of first scissor records to set
 121  * \param count  number of scissor records to set
 122  * \param x, y   pointer to array of struct gl_scissor_rects
 123  *
 124  * \sa glScissorArrayv().
 125  *
 126  * Verifies the parameters and call set_scissor_no_notify to do the work.
 127  */
 128 void GLAPIENTRY
 129 _mesa_ScissorArrayv(GLuint first, GLsizei count, const GLint *v)
 130 {
 131    int i;
 132    struct gl_scissor_rect *p = (struct gl_scissor_rect *) v;
 133    GET_CURRENT_CONTEXT(ctx);
 134
 135    if ((first + count) > ctx->Const.MaxViewports) {
 136       _mesa_error(ctx, GL_INVALID_VALUE,
 137                   "glScissorArrayv: first (%d) + count (%d) >= MaxViewports (%d)",
 138                   first, count, ctx->Const.MaxViewports);
 139       return;
 140    }
 141
 142    /* Verify width & height */
 143    for (i = 0; i < count; i++) {
 144       if (p[i].Width < 0 || p[i].Height < 0) {
 145          _mesa_error(ctx, GL_INVALID_VALUE,
 146                      "glScissorArrayv: index (%d) width or height < 0 (%d, %d)",
 147                      i, p[i].Width, p[i].Height);
 148          return;
 149       }
 150    }
 151
 152    for (i = 0; i < count; i++)
 153       set_scissor_no_notify(ctx, i + first,
 154                             p[i].X, p[i].Y, p[i].Width, p[i].Height);
 155
 156    if (ctx->Driver.Scissor)
 157       ctx->Driver.Scissor(ctx);
 158 }
 159
 160 /**
 161  * Define the scissor box.
 162  *
 163  * \param index  index of scissor records to set
 164  * \param x, y   coordinates of the scissor box lower-left corner.
 165  * \param width  width of the scissor box.
 166  * \param height height of the scissor box.
 167  *
 168  * Verifies the parameters call set_scissor_no_notify to do the work.
 169  */
 170 static void
 171 ScissorIndexed(GLuint index, GLint left, GLint bottom,
 172                GLsizei width, GLsizei height, const char *function)
 173 {
 174    GET_CURRENT_CONTEXT(ctx);
 175
 176    if (MESA_VERBOSE & VERBOSE_API)
 177       _mesa_debug(ctx, "%s(%d, %d, %d, %d, %d)\n",
 178                   function, index, left, bottom, width, height);
 179
 180    if (index >= ctx->Const.MaxViewports) {
 181       _mesa_error(ctx, GL_INVALID_VALUE,
 182                   "%s: index (%d) >= MaxViewports (%d)",
 183                   function, index, ctx->Const.MaxViewports);
 184       return;
 185    }
 186
 187    if (width < 0 || height < 0) {
 188       _mesa_error(ctx, GL_INVALID_VALUE,
 189                   "%s: index (%d) width or height < 0 (%d, %d)",
 190                   function, index, width, height);
 191       return;
 192    }
 193
 194    set_scissor_no_notify(ctx, index, left, bottom, width, height);
 195
 196    if (ctx->Driver.Scissor)
 197       ctx->Driver.Scissor(ctx);
 198 }
 199
 200 void GLAPIENTRY
 201 _mesa_ScissorIndexed(GLuint index, GLint left, GLint bottom,
 202                      GLsizei width, GLsizei height)
 203 {
 204    ScissorIndexed(index, left, bottom, width, height, "glScissorIndexed");
 205 }
 206
 207 void GLAPIENTRY
 208 _mesa_ScissorIndexedv(GLuint index, const GLint *v)
 209 {
 210    ScissorIndexed(index, v[0], v[1], v[2], v[3], "glScissorIndexedv");
 211 }
 212
 213 /**
 214  * Initialize the context's scissor state.
 215  * \param ctx  the GL context.
 216  */
 217 void
 218 _mesa_init_scissor(struct gl_context *ctx)
 219 {
 220    unsigned i;
 221
 222    /* Scissor group */
 223    ctx->Scissor.EnableFlags = 0;
 224
 225    /* Note: ctx->Const.MaxViewports may not have been set by the driver yet,
 226     * so just initialize all of them.
 227     */
 228    for (i = 0; i < MAX_VIEWPORTS; i++)
 229       set_scissor_no_notify(ctx, i, 0, 0, 0, 0);
 230 }