2 * Mesa 3-D graphics library
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28 * glViewport and glDepthRange functions.
40 * \sa Called via glViewport() or display list execution.
42 * Flushes the vertices and calls _mesa_set_viewport() with the given
46 _mesa_Viewport(GLint x
, GLint y
, GLsizei width
, GLsizei height
)
48 GET_CURRENT_CONTEXT(ctx
);
49 FLUSH_VERTICES(ctx
, 0);
50 _mesa_set_viewport(ctx
, x
, y
, width
, height
);
55 * Set new viewport parameters and update derived state (the _WindowMap
56 * matrix). Usually called from _mesa_Viewport().
58 * \param ctx GL context.
59 * \param x, y coordinates of the lower left corner of the viewport rectangle.
60 * \param width width of the viewport rectangle.
61 * \param height height of the viewport rectangle.
64 _mesa_set_viewport(struct gl_context
*ctx
, GLint x
, GLint y
,
65 GLsizei width
, GLsizei height
)
67 if (MESA_VERBOSE
& VERBOSE_API
)
68 _mesa_debug(ctx
, "glViewport %d %d %d %d\n", x
, y
, width
, height
);
70 if (width
< 0 || height
< 0) {
71 _mesa_error(ctx
, GL_INVALID_VALUE
,
72 "glViewport(%d, %d, %d, %d)", x
, y
, width
, height
);
76 /* clamp width and height to the implementation dependent range */
77 width
= MIN2(width
, (GLsizei
) ctx
->Const
.MaxViewportWidth
);
78 height
= MIN2(height
, (GLsizei
) ctx
->Const
.MaxViewportHeight
);
81 ctx
->Viewport
.Width
= width
;
83 ctx
->Viewport
.Height
= height
;
84 ctx
->NewState
|= _NEW_VIEWPORT
;
87 /* XXX remove this someday. Currently the DRI drivers rely on
88 * the WindowMap matrix being up to date in the driver's Viewport
89 * and DepthRange functions.
91 _math_matrix_viewport(&ctx
->Viewport
._WindowMap
,
92 ctx
->Viewport
.X
, ctx
->Viewport
.Y
,
93 ctx
->Viewport
.Width
, ctx
->Viewport
.Height
,
94 ctx
->Viewport
.Near
, ctx
->Viewport
.Far
,
95 ctx
->DrawBuffer
->_DepthMaxF
);
98 if (ctx
->Driver
.Viewport
) {
99 /* Many drivers will use this call to check for window size changes
100 * and reallocate the z/stencil/accum/etc buffers if needed.
102 ctx
->Driver
.Viewport(ctx
, x
, y
, width
, height
);
108 * Called by glDepthRange
110 * \param nearval specifies the Z buffer value which should correspond to
111 * the near clip plane
112 * \param farval specifies the Z buffer value which should correspond to
116 _mesa_DepthRange(GLclampd nearval
, GLclampd farval
)
118 GET_CURRENT_CONTEXT(ctx
);
120 FLUSH_VERTICES(ctx
, 0);
122 if (MESA_VERBOSE
&VERBOSE_API
)
123 _mesa_debug(ctx
, "glDepthRange %f %f\n", nearval
, farval
);
125 if (ctx
->Viewport
.Near
== nearval
&&
126 ctx
->Viewport
.Far
== farval
)
129 ctx
->Viewport
.Near
= (GLfloat
) CLAMP(nearval
, 0.0, 1.0);
130 ctx
->Viewport
.Far
= (GLfloat
) CLAMP(farval
, 0.0, 1.0);
131 ctx
->NewState
|= _NEW_VIEWPORT
;
134 /* XXX remove this someday. Currently the DRI drivers rely on
135 * the WindowMap matrix being up to date in the driver's Viewport
136 * and DepthRange functions.
138 _math_matrix_viewport(&ctx
->Viewport
._WindowMap
,
139 ctx
->Viewport
.X
, ctx
->Viewport
.Y
,
140 ctx
->Viewport
.Width
, ctx
->Viewport
.Height
,
141 ctx
->Viewport
.Near
, ctx
->Viewport
.Far
,
142 ctx
->DrawBuffer
->_DepthMaxF
);
145 if (ctx
->Driver
.DepthRange
) {
146 ctx
->Driver
.DepthRange(ctx
, nearval
, farval
);
151 _mesa_DepthRangef(GLclampf nearval
, GLclampf farval
)
153 _mesa_DepthRange(nearval
, farval
);
157 * Initialize the context viewport attribute group.
158 * \param ctx the GL context.
160 void _mesa_init_viewport(struct gl_context
*ctx
)
162 GLfloat depthMax
= 65535.0F
; /* sorf of arbitrary */
167 ctx
->Viewport
.Width
= 0;
168 ctx
->Viewport
.Height
= 0;
169 ctx
->Viewport
.Near
= 0.0;
170 ctx
->Viewport
.Far
= 1.0;
171 _math_matrix_ctr(&ctx
->Viewport
._WindowMap
);
173 _math_matrix_viewport(&ctx
->Viewport
._WindowMap
, 0, 0, 0, 0,
174 0.0F
, 1.0F
, depthMax
);
179 * Free the context viewport attribute group data.
180 * \param ctx the GL context.
182 void _mesa_free_viewport_data(struct gl_context
*ctx
)
184 _math_matrix_dtr(&ctx
->Viewport
._WindowMap
);