diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/mesa/main/dd.h | 55 |
1 files changed, 32 insertions, 23 deletions
diff --git a/src/mesa/main/dd.h b/src/mesa/main/dd.h index 64b031e4e1..3173e144ae 100644 --- a/src/mesa/main/dd.h +++ b/src/mesa/main/dd.h @@ -1,4 +1,4 @@ -/* $Id: dd.h,v 1.3 1999/09/30 11:18:21 keithw Exp $ */ +/* $Id: dd.h,v 1.4 1999/10/21 12:46:27 brianp Exp $ */ /* * Mesa 3-D graphics library @@ -63,10 +63,10 @@ struct gl_pipeline_stage; * The optional functions provide ways to take advantage of special hardware * or optimized algorithms. * - * The function pointers in the dd_function_table struct are first - * initialized in the "MakeCurrent" function. The "MakeCurrent" function - * is a little different in each device driver. See the X/Mesa, GLX, or - * OS/Mesa drivers for examples. + * The function pointers in the dd_function_table struct should first be + * initialized in the driver's "MakeCurrent" function. The "MakeCurrent" + * function is a little different in each device driver. See the X/Mesa, + * GLX, or OS/Mesa drivers for examples. * * Later, Mesa may call the dd_function_table's UpdateState() function. * This function should initialize the dd_function_table's pointers again. @@ -81,7 +81,8 @@ struct gl_pipeline_stage; * for an example. * * For more information about writing a device driver see the ddsample.c - * file and other device drivers (xmesa[123].c, osmesa.c, etc) for examples. + * file and other device drivers (X/xmesa[1234].c, OSMesa/osmesa.c, etc) + * for examples. * * * Look below in the dd_function_table struct definition for descriptions @@ -132,8 +133,8 @@ struct dd_function_table { const char * (*RendererString)(void); /* * Return a string which uniquely identifies this device driver. - * The string should contain no whitespace. Examples: "X11" "OffScreen" - * "MSWindows" "SVGA". + * The string should contain no whitespace. Examples: "X11", "OffScreen", + * "MSWindows", "SVGA". * NOTE: This function will be obsolete in favor of GetString in the future! */ @@ -147,14 +148,14 @@ struct dd_function_table { void (*ClearIndex)( GLcontext *ctx, GLuint index ); /* * Called whenever glClearIndex() is called. Set the index for clearing - * the color buffer. + * the color buffer when in color index mode. */ void (*ClearColor)( GLcontext *ctx, GLubyte red, GLubyte green, GLubyte blue, GLubyte alpha ); /* * Called whenever glClearColor() is called. Set the color for clearing - * the color buffer. + * the color buffer when in RGBA mode. */ GLbitfield (*Clear)( GLcontext *ctx, GLbitfield mask, GLboolean all, @@ -169,12 +170,14 @@ struct dd_function_table { void (*Index)( GLcontext *ctx, GLuint index ); /* * Sets current color index for drawing flat-shaded primitives. + * This index should also be used in the "mono" drawing functions. */ void (*Color)( GLcontext *ctx, GLubyte red, GLubyte green, GLubyte glue, GLubyte alpha ); /* * Sets current color for drawing flat-shaded primitives. + * This color should also be used in the "mono" drawing functions. */ GLboolean (*SetBuffer)( GLcontext *ctx, GLenum buffer ); @@ -197,8 +200,7 @@ struct dd_function_table { * GL_NONE - disable buffer write in device driver. */ - void (*GetBufferSize)( GLcontext *ctx, - GLuint *width, GLuint *height ); + void (*GetBufferSize)( GLcontext *ctx, GLuint *width, GLuint *height ); /* * Returns the width and height of the current color buffer. */ @@ -216,11 +218,14 @@ struct dd_function_table { CONST GLubyte rgb[][3], const GLubyte mask[] ); /* Write a horizontal run of RGB[A] pixels. The later version is only * used to accelerate GL_RGB, GL_UNSIGNED_BYTE glDrawPixels() calls. + * If mask is NULL, draw all pixels. + * If mask is not null, only draw pixel [i] when mask [i] is true. */ void (*WriteMonoRGBASpan)( const GLcontext *ctx, GLuint n, GLint x, GLint y, const GLubyte mask[] ); - /* Write a horizontal run of mono-RGBA pixels. + /* Write a horizontal run of RGBA pixels all with the color last + * specified by the Color function. */ void (*WriteRGBAPixels)( const GLcontext *ctx, @@ -239,12 +244,15 @@ struct dd_function_table { const GLuint index[], const GLubyte mask[] ); void (*WriteCI8Span)( const GLcontext *ctx, GLuint n, GLint x, GLint y, const GLubyte index[], const GLubyte mask[] ); - /* Write a horizontal run of CI pixels. 32 or 8bpp. + /* Write a horizontal run of CI pixels. One function is for 32bpp + * indexes and the other for 8bpp pixels (the common case). You mus + * implement both for color index mode. */ void (*WriteMonoCISpan)( const GLcontext *ctx, GLuint n, GLint x, GLint y, const GLubyte mask[] ); - /* Write a horizontal run of mono-CI pixels. + /* Write a horizontal run of color index pixels using the color index + * last specified by the Index() function. */ void (*WriteCI32Pixels)( const GLcontext *ctx, @@ -257,8 +265,8 @@ struct dd_function_table { void (*WriteMonoCIPixels)( const GLcontext *ctx, GLuint n, const GLint x[], const GLint y[], const GLubyte mask[] ); - /* - * Write a random array of mono-CI pixels. + /* Write a random array of color index pixels using the color index + * last specified by the Index() function. */ @@ -310,12 +318,12 @@ struct dd_function_table { void (*Finish)( GLcontext *ctx ); /* - * Called whenever glFinish() is called. + * This is called whenever glFinish() is called. */ void (*Flush)( GLcontext *ctx ); /* - * Called whenever glFlush() is called. + * This is called whenever glFlush() is called. */ GLboolean (*IndexMask)( GLcontext *ctx, GLuint mask ); @@ -418,16 +426,17 @@ struct dd_function_table { GLenum format, GLenum type, const struct gl_pixelstore_attrib *unpack, const GLvoid *pixels ); - /* Device driver hook for optimized glDrawPixels. 'unpack' describes how - * to unpack the source image data. + /* This is called by glDrawPixels. + * 'unpack' describes how to unpack the source image data. + * Return GL_TRUE if the driver succeeds, return GL_FALSE if core Mesa + * must do the job. */ GLboolean (*Bitmap)( GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height, const struct gl_pixelstore_attrib *unpack, const GLubyte *bitmap ); - /* Device driver hook for optimized glBitmap. 'unpack' describes how - * to unpack the source image data. + /* This is called by glBitmap. Works the same as DrawPixels, above. */ void (*RenderStart)( GLcontext *ctx ); |