1GLTEXIMAGE2D(3G) GLTEXIMAGE2D(3G)
2
6 glTexImage2D - specify a two-dimensional texture image
7
10 void glTexImage2D( GLenum target,
11 GLint level,
12 GLint internalFormat,
13 GLsizei width,
14 GLsizei height,
15 GLint border,
16 GLenum format,
17 GLenum type,
18 const GLvoid *pixels )
19
22 target Specifies the target texture. Must be GL_TEXTURE_2D or
23 GL_PROXY_TEXTURE_2D.
24 level Specifies the level-of-detail number. Level 0 is the
26 base image level. Level n is the nth mipmap reduction
27 image.
28 internalFormat Specifies the number of color components in the tex‐
30 ture. Must be 1, 2, 3, or 4, or one of the following
31 symbolic constants: GL_ALPHA, GL_ALPHA4, GL_ALPHA8,
32 GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4,
33 GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16,
34 GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4,
35 GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8,
36 GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12,
37 GL_LUMINANCE16_ALPHA16, GL_INTENSITY, GL_INTENSITY4,
38 GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16,
39 GL_R3_G3_B2, GL_RGB, GL_RGB4, GL_RGB5, GL_RGB8,
40 GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2,
41 GL_RGBA4, GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12,
42 or GL_RGBA16.
43 width Specifies the width of the texture image. Must be
45 2n+2(border) for some integer n. All implementations
46 support texture images that are at least 64 texels
47 wide.
48 height Specifies the height of the texture image. Must be
50 2m+2(border) for some integer m. All implementations
51 support texture images that are at least 64 texels
52 high.
53 border Specifies the width of the border. Must be either 0 or
55 1.
56 format Specifies the of the pixel data. The following sym‐
58 bolic values are accepted: GL_COLOR_INDEX, GL_RED,
59 GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR GL_RGBA,
60 GL_BGRA, GL_LUMINANCE, and GL_LUMINANCE_ALPHA.
61 type Specifies the data type of the pixel data. The follow‐
63 ing symbolic values are accepted: GL_UNSIGNED_BYTE,
64 GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT,
65 GL_UNSIGNED_INT, GL_INT, GL_FLOAT,
66 GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV,
67 GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV,
68 GL_UNSIGNED_SHORT_4_4_4_4,
69 GL_UNSIGNED_SHORT_4_4_4_4_REV,
70 GL_UNSIGNED_SHORT_5_5_5_1,
71 GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8,
72 GL_UNSIGNED_INT_8_8_8_8_REV,
73 GL_UNSIGNED_INT_10_10_10_2, and
74 GL_UNSIGNED_INT_2_10_10_10_REV.
75 pixels Specifies a pointer to the image data in memory.
77
79 Texturing maps a portion of a specified texture image onto each graphi‐
80 cal primitive for which texturing is enabled. To enable and disable
81 two-dimensional texturing, call glEnable and glDisable with argument
82 GL_TEXTURE_2D.
83 To define texture images, call glTexImage2D. The arguments describe
85 the parameters of the texture image, such as height, width, width of
86 the border, level-of-detail number (see glTexParameter), and number of
87 color components provided. The last three arguments describe how the
88 image is represented in memory; they are identical to the pixel formats
89 used for glDrawPixels.
90 If target is GL_PROXY_TEXTURE_2D, no data is read from pixels, but all
92 of the texture image state is recalculated, checked for consistency,
93 and checked against the implementation's capabilities. If the implemen‐
94 tation cannot handle a texture of the requested texture size, it sets
95 all of the image state to 0, but does not generate an error (see
96 glGetError). To query for an entire mipmap array, use an image array
97 level greater than or equal to 1.
98 If target is GL_TEXTURE_2D, data is read from pixels as a sequence of
100 signed or unsigned bytes, shorts, or longs, or single-precision float‐
101 ing-point values, depending on type. These values are grouped into
102 sets of one, two, three, or four values, depending on format, to form
103 elements. If type is GL_BITMAP, the data is considered as a string of
104 unsigned bytes (and format must be GL_COLOR_INDEX).
105 Each data byte is treated as eight 1-bit elements, with bit ordering
106 determined by GL_UNPACK_LSB_FIRST (see glPixelStore).
107 The first element corresponds to the lower left corner of the texture
109 image. Subsequent elements progress left-to-right through the remain‐
110 ing texels in the lowest row of the texture image, and then in succes‐
111 sively higher rows of the texture image. The final element corresponds
112 to the upper right corner of the texture image.
113 format determines the composition of each element in pixels. It can
115 assume one of eleven symbolic values:
116 GL_COLOR_INDEX
118 Each element is a single value, a color index. The GL con‐
119 verts it to fixed point (with an unspecified number of zero
120 bits to the right of the binary point), shifted left or right
121 depending on the value and sign of GL_INDEX_SHIFT, and added
122 to GL_INDEX_OFFSET (see
123 glPixelTransfer). The resulting index is converted to a set
124 of color components using the GL_PIXEL_MAP_I_TO_R,
125 GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, and
126 GL_PIXEL_MAP_I_TO_A tables, and clamped to the range [0,1].
127 GL_RED Each element is a single red component. The GL converts it
129 to floating point and assembles it into an RGBA element by
130 attaching 0 for green and blue, and 1 for alpha. Each compo‐
131 nent is then multiplied by the signed scale factor
132 GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped
133 to the range [0,1] (see glPixelTransfer).
134 GL_GREEN Each element is a single green component. The GL converts it
136 to floating point and assembles it into an RGBA element by
137 attaching 0 for red and blue, and 1 for alpha. Each compo‐
138 nent is then multiplied by the signed scale factor
139 GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped
140 to the range [0,1] (see glPixelTransfer).
141 GL_BLUE Each element is a single blue component. The GL converts it
143 to floating point and assembles it into an RGBA element by
144 attaching 0 for red and green, and 1 for alpha. Each compo‐
145 nent is then multiplied by the signed scale factor
146 GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped
147 to the range [0,1] (see glPixelTransfer).
148 GL_ALPHA Each element is a single alpha component. The GL converts it
150 to floating point and assembles it into an RGBA element by
151 attaching 0 for red, green, and blue. Each component is then
152 multiplied by the signed scale factor GL_c_SCALE, added to
153 the signed bias GL_c_BIAS, and clamped to the range [0,1]
154 (see glPixelTransfer).
155 GL_RGB
157 GL_BGR Each element is an RGB triple. The GL converts it to float‐
159 ing point and assembles it into an RGBA element by attaching
160 1 for alpha. Each component is then multiplied by the signed
161 scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS,
162 and clamped to the range [0,1] (see
163 glPixelTransfer).
164 GL_RGBA
166 GL_BGRA Each element contains all four components. Each component is
168 multiplied by the signed scale factor GL_c_SCALE, added to
169 the signed bias GL_c_BIAS, and clamped to the range [0,1]
170 (see glPixelTransfer).
171 GL_LUMINANCE
173 Each element is a single luminance value. The GL converts it
174 to floating point, then assembles it into an RGBA element by
175 replicating the luminance value three times for red, green,
176 and blue and attaching 1 for alpha. Each component is then
177 multiplied by the signed scale factor GL_c_SCALE, added to
178 the signed bias GL_c_BIAS, and clamped to the range [0,1]
179 (see glPixelTransfer).
180 GL_LUMINANCE_ALPHA
182 Each element is a luminance/alpha pair. The GL converts it
183 to floating point, then assembles it into an RGBA element by
184 replicating the luminance value three times for red, green,
185 and blue. Each component is then multiplied by the signed
186 scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS,
187 and clamped to the range [0,1] (see
188 glPixelTransfer).
189 Refer to the glDrawPixels reference page for a description of the
191 acceptable values for the type parameter.
192 If an application wants to store the texture at a certain resolution or
194 in a certain , it can request the resolution and with internalFormat.
195 The GL will choose an internal representation that closely approximates
196 that requested by internalFormat, but it may not match exactly. (The
197 representations specified by GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_RGB,
198 and GL_RGBA must match exactly. The numeric values 1, 2, 3, and 4 may
199 also be used to specify the above representations.)
200 Use the GL_PROXY_TEXTURE_2D target to try out a resolution and update
202 and recompute its best match for the requested storage resolution and .
203 To then query this state, call glGetTexLevelParameter. If the texture
204 cannot be accommodated, texture state is set to 0.
205 A one-component texture image uses only the red component of the RGBA
207 color extracted from pixels. A two-component image uses the R and A
208 values. A three-component image uses the R, G, and B values. A four-
209 component image uses all of the RGBA components.
210
212 Texturing has no effect in color index mode.
213 If the GL_ARB_imaging extension is supported, RGBA elements may also be
215 processed by the imaging pipeline. The following stages may be applied
216 to an RGBA color before color component clamping to the range [0, 1]:
217 1. Color component replacement by the color table specified for
219 GL_COLOR_TABLE, if enabled. See glColorTable.
220 2. Two-dimensional Convolution filtering, if enabled. See
222 glConvolutionFilter1D.
223 If a convolution filter changes the __width of the texture (by pro‐
225 cessing with a GL_CONVOLUTION_BORDER_MODE of GL_REDUCE, for exam‐
226 ple), the width must 2n+2(height), for some integer n, and height
227 must be 2m+(border), for some integer m, after filtering.
228 3. RGBA components may be multiplied by GL_POST_CONVOLUTION_c_SCALE,
230 and added to GL_POST_CONVOLUTION_c_BIAS, if enabled. See
231 glPixelTransfer.
232 4. Color component replacement by the color table specified for
234 GL_POST_CONVOLUTION_COLOR_TABLE, if enabled. See glColorTable.
235 5. Transformation by the color matrix. See glMatrixMode.
237 6. RGBA components may be multiplied by GL_POST_COLOR_MATRIX_c_SCALE,
239 and added to GL_POST_COLOR_MATRIX_c_BIAS, if enabled. See
240 glPixelTransfer.
241 7. Color component replacement by the color table specified for
243 GL_POST_COLOR_MATRIX_COLOR_TABLE, if enabled. See glColorTable.
244 The texture image can be represented by the same data formats as the
246 pixels in a glDrawPixels command, except that GL_STENCIL_INDEX and
247 GL_DEPTH_COMPONENT cannot be used. glPixelStore and glPixelTransfer
248 modes affect texture images in exactly the way they affect
249 glDrawPixels.
250 glTexImage2D and GL_PROXY_TEXTURE_2D are available only if the GL ver‐
252 sion is 1.1 or greater.
253 Internal formats other than 1, 2, 3, or 4 may be used only if the GL
255 version is 1.1 or greater.
256 In GL version 1.1 or greater, pixels may be a null pointer. In this
258 case texture memory is allocated to accommodate a texture of width
259 width and height height. You can then download subtextures to initial‐
260 ize this texture memory. The image is undefined if the user tries to
261 apply an uninitialized portion of the texture image to a primitive.
262 Formats GL_BGR, and GL_BGRA and types GL_UNSIGNED_BYTE_3_3_2,
264 GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5,
265 GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4,
266 GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1,
267 GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8,
268 GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and
269 GL_UNSIGNED_INT_2_10_10_10_REV are available only if the GL version is
270 1.2 or greater.
271 When the GL_ARB_multitexture extension is supported, glTexImage2D spec‐
273 ifies the two-dimensional texture for the current texture unit, speci‐
274 fied with glActiveTextureARB.
275
277 GL_INVALID_ENUM is generated if target is not GL_TEXTURE_2D or
278 GL_PROXY_TEXTURE_2D.
279 GL_INVALID_ENUM is generated if format is not an accepted
281 constant. Format constants other than GL_STENCIL_INDEX and
282 GL_DEPTH_COMPONENT are accepted.
283 GL_INVALID_ENUM is generated if type is not a type constant.
285 GL_INVALID_ENUM is generated if type is GL_BITMAP and format is not
287 GL_COLOR_INDEX.
288 GL_INVALID_VALUE is generated if level is less than 0.
290 GL_INVALID_VALUE may be generated if level is greater than log2max,
292 where max is the returned value of GL_MAX_TEXTURE_SIZE.
293 GL_INVALID_VALUE is generated if internalFormat is not 1, 2, 3, 4, or
295 one of the accepted resolution and symbolic constants.
296 GL_INVALID_VALUE is generated if width or height is less than 0 or
298 greater than 2 + GL_MAX_TEXTURE_SIZE, or if either cannot be repre‐
299 sented as 2k+2(border) for some integer value of k.
300 GL_INVALID_VALUE is generated if border is not 0 or 1.
302 GL_INVALID_OPERATION is generated if glTexImage2D is executed between
304 the execution of glBegin and the corresponding execution of glEnd.
305 GL_INVALID_OPERATION is generated if type is one of
307 GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV,
308 GL_UNSIGNED_SHORT_5_6_5, or GL_UNSIGNED_SHORT_5_6_5_REV and format is
309 not GL_RGB.
310 GL_INVALID_OPERATION is generated if type is one of
312 GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV,
313 GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV,
314 GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV,
315 GL_UNSIGNED_INT_10_10_10_2, or GL_UNSIGNED_INT_2_10_10_10_REV and for‐
316 mat is neither GL_RGBA nor GL_BGRA.
317
319 glGetTexImage
320 glIsEnabled with argument GL_TEXTURE_2D
321
323 glColorTable(3G), glConvolutionFilter2D(3G), glCopyPixels(3G),
324 glCopyTexImage1D(3G), glCopyTexImage2D(3G), glCopyTexSubImage1D(3G),
325 glCopyTexSubImage2D(3G), glCopyTexSubImage3D(3G), glDrawPixels(3G),
326 glMatrixMode(3G), glPixelStore(3G), glPixelTransfer(3G),
327 glSeparableFilter2D(3G), glTexEnv(3G), glTexGen(3G), glTexImage1D(3G),
328 glTexImage3D(3G), glTexSubImage1D(3G), glTexSubImage2D(3G),
329 glTexSubImage3D(3G), glTexParameter(3G)
330 GLTEXIMAGE2D(3G)