src/mesa/state_tracker/st_util.h

   1 /**************************************************************************
   2  *
   3  * Copyright 2019 VMware, Inc.
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  11  * permit persons to whom the Software is furnished to do so, subject to
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  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
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  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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  25  *
  26  **************************************************************************/
  27
  28
  29 /*
  30  * Miscellantous state tracker utility functions, macros.
  31  */
  32
  33
  34 #ifndef ST_UTIL
  35 #define ST_UTIL
  36
  37
  38 #include "state_tracker/st_context.h"
  39
  40
  41 #ifdef __cplusplus
  42 extern "C" {
  43 #endif
  44
  45
  46 /** For drawing quads for glClear, glDraw/CopyPixels, glBitmap, etc. */
  47 struct st_util_vertex
  48 {
  49    float x, y, z;
  50    float r, g, b, a;
  51    float s, t;
  52 };
  53
  54
  55
  56 /* Invalidate the readpixels cache to ensure we don't read stale data.
  57  */
  58 static inline void
  59 st_invalidate_readpix_cache(struct st_context *st)
  60 {
  61    if (unlikely(st->readpix_cache.src)) {
  62       pipe_resource_reference(&st->readpix_cache.src, NULL);
  63       pipe_resource_reference(&st->readpix_cache.cache, NULL);
  64    }
  65 }
  66
  67
  68 #define Y_0_TOP 1
  69 #define Y_0_BOTTOM 2
  70
  71 static inline GLuint
  72 st_fb_orientation(const struct gl_framebuffer *fb)
  73 {
  74    if (fb && fb->FlipY) {
  75       /* Drawing into a window (on-screen buffer).
  76        *
  77        * Negate Y scale to flip image vertically.
  78        * The NDC Y coords prior to viewport transformation are in the range
  79        * [y=-1=bottom, y=1=top]
  80        * Hardware window coords are in the range [y=0=top, y=H-1=bottom] where
  81        * H is the window height.
  82        * Use the viewport transformation to invert Y.
  83        */
  84       return Y_0_TOP;
  85    }
  86    else {
  87       /* Drawing into user-created FBO (very likely a texture).
  88        *
  89        * For textures, T=0=Bottom, so by extension Y=0=Bottom for rendering.
  90        */
  91       return Y_0_BOTTOM;
  92    }
  93 }
  94
  95
  96 static inline bool
  97 st_user_clip_planes_enabled(struct gl_context *ctx)
  98 {
  99    return (ctx->API == API_OPENGL_COMPAT ||
 100            ctx->API == API_OPENGLES) && /* only ES 1.x */
 101           ctx->Transform.ClipPlanesEnabled;
 102 }
 103
 104 static inline bool
 105 st_point_size_per_vertex(struct gl_context *ctx)
 106 {
 107    const struct gl_program *vertProg = ctx->VertexProgram._Current;
 108    if (vertProg) {
 109       if (vertProg->Id == 0) {
 110          if (vertProg->info.outputs_written &
 111              BITFIELD64_BIT(VARYING_SLOT_PSIZ)) {
 112             /* generated program which emits point size */
 113             return true;
 114          }
 115       }
 116       else if (ctx->API != API_OPENGLES2) {
 117          /* PointSizeEnabled is always set in ES2 contexts */
 118          return ctx->VertexProgram.PointSizeEnabled;
 119       }
 120       else {
 121          /* ST_NEW_TESSEVAL_PROGRAM | ST_NEW_GEOMETRY_PROGRAM */
 122          /* We have to check the last bound stage and see if it writes psize */
 123          struct gl_program *last = NULL;
 124          if (ctx->GeometryProgram._Current)
 125             last = ctx->GeometryProgram._Current;
 126          else if (ctx->TessEvalProgram._Current)
 127             last = ctx->TessEvalProgram._Current;
 128          else if (ctx->VertexProgram._Current)
 129             last = ctx->VertexProgram._Current;
 130          if (last)
 131             return !!(last->info.outputs_written &
 132                       BITFIELD64_BIT(VARYING_SLOT_PSIZ));
 133       }
 134    }
 135    return false;
 136 }
 137
 138 /** clear-alloc a struct-sized object, with casting */
 139 #define ST_CALLOC_STRUCT(T)   (struct T *) calloc(1, sizeof(struct T))
 140
 141
 142 #ifdef __cplusplus
 143 }
 144 #endif
 145
 146
 147 #endif /* ST_UTIL */