Fix T62876: Camera Background Images

Migrate old legacy code to the draw mamager/object mode. The old legacy
version did not work with wireframe. By migrating the code
to modern draw manager code we have mode control on the drawing process.

Still background images do not work with OIT, the cause seems to be that the transparent pixels are treated as background pixels.
Also There are some artifacts when working with Holdouts and DoF, this
is because the draw engines do not pass the correct alpha values.

Reviewers: fclem, brecht

Differential Revision: https://developer.blender.org/D4638

1 files changed, 79 insertions, 3 deletions

diff --git a/source/blender/gpu/intern/gpu_draw.c b/source/blender/gpu/intern/gpu_draw.c
index 7813ae68371..f5d599eb647 100644
--- a/source/blender/gpu/intern/gpu_draw.c
+++ b/source/blender/gpu/intern/gpu_draw.c
@@ -59,6 +59,7 @@
 #include "BKE_image.h"
 #include "BKE_main.h"
 #include "BKE_material.h"
+#include "BKE_movieclip.h"
 #include "BKE_node.h"
 #include "BKE_scene.h"
 
@@ -247,7 +248,7 @@ static uint gpu_texture_create_from_ibuf(Image *ima, ImBuf *ibuf, int textarget)
        * this allows us to use sRGB texture formats and preserves color values in
        * zero alpha areas, and appears generally closer to what game engines that we
        * want to be compatible with do. */
-      const bool store_premultiplied = (ima->alpha_mode == IMA_ALPHA_PREMUL);
+      const bool store_premultiplied = ima ? (ima->alpha_mode == IMA_ALPHA_PREMUL) : true;
       IMB_colormanagement_imbuf_to_byte_texture(
           rect, 0, 0, ibuf->x, ibuf->y, ibuf, compress_as_srgb, store_premultiplied);
     }
@@ -256,14 +257,13 @@ static uint gpu_texture_create_from_ibuf(Image *ima, ImBuf *ibuf, int textarget)
     /* Float image is already in scene linear colorspace or non-color data by
      * convention, no colorspace conversion needed. But we do require 4 channels
      * currently. */
-    const bool store_premultiplied = (ima->alpha_mode != IMA_ALPHA_STRAIGHT);
+    const bool store_premultiplied = ima ? (ima->alpha_mode != IMA_ALPHA_STRAIGHT) : false;
 
     if (ibuf->channels != 4 || !store_premultiplied) {
       rect_float = MEM_mallocN(sizeof(float) * 4 * ibuf->x * ibuf->y, __func__);
       if (rect_float == NULL) {
         return bindcode;
       }
-
       IMB_colormanagement_imbuf_to_float_texture(
           rect_float, 0, 0, ibuf->x, ibuf->y, ibuf, store_premultiplied);
     }
@@ -291,6 +291,36 @@ static uint gpu_texture_create_from_ibuf(Image *ima, ImBuf *ibuf, int textarget)
   return bindcode;
 }
 
+static GPUTexture **gpu_get_movieclip_gputexture(MovieClip *clip,
+                                                 MovieClipUser *cuser,
+                                                 GLenum textarget)
+{
+  MovieClip_RuntimeGPUTexture *tex;
+  for (tex = clip->runtime.gputextures.first; tex; tex = tex->next) {
+    if (memcmp(&tex->user, cuser, sizeof(MovieClipUser)) == 0) {
+      break;
+    }
+  }
+
+  if (tex == NULL) {
+    tex = MEM_mallocN(sizeof(MovieClip_RuntimeGPUTexture), __func__);
+
+    for (int i = 0; i < TEXTARGET_COUNT; i++) {
+      tex->gputexture[i] = NULL;
+    }
+
+    memcpy(&tex->user, cuser, sizeof(MovieClipUser));
+    BLI_addtail(&clip->runtime.gputextures, tex);
+  }
+
+  if (textarget == GL_TEXTURE_2D)
+    return &tex->gputexture[TEXTARGET_TEXTURE_2D];
+  else if (textarget == GL_TEXTURE_CUBE_MAP)
+    return &tex->gputexture[TEXTARGET_TEXTURE_CUBE_MAP];
+
+  return NULL;
+}
+
 static void gpu_texture_update_scaled(
     uchar *rect, float *rect_float, int full_w, int full_h, int x, int y, int w, int h)
 {
@@ -472,6 +502,52 @@ GPUTexture *GPU_texture_from_blender(Image *ima, ImageUser *iuser, int textarget
   return *tex;
 }
 
+GPUTexture *GPU_texture_from_movieclip(MovieClip *clip, MovieClipUser *cuser, int textarget)
+{
+  if (clip == NULL) {
+    return NULL;
+  }
+
+  GPUTexture **tex = gpu_get_movieclip_gputexture(clip, cuser, textarget);
+  if (*tex) {
+    return *tex;
+  }
+
+  /* check if we have a valid image buffer */
+  uint bindcode = 0;
+  ImBuf *ibuf = BKE_movieclip_get_ibuf(clip, cuser);
+  if (ibuf == NULL) {
+    *tex = GPU_texture_from_bindcode(textarget, bindcode);
+    return *tex;
+  }
+
+  bindcode = gpu_texture_create_from_ibuf(NULL, ibuf, textarget);
+  IMB_freeImBuf(ibuf);
+
+  *tex = GPU_texture_from_bindcode(textarget, bindcode);
+  return *tex;
+}
+
+void GPU_free_texture_movieclip(struct MovieClip *clip)
+{
+  /* number of gpu textures to keep around as cache
+   * We don't want to keep too many GPU textures for
+   * movie clips around, as they can be large.*/
+  const int MOVIECLIP_NUM_GPUTEXTURES = 1;
+
+  while (BLI_listbase_count(&clip->runtime.gputextures) > MOVIECLIP_NUM_GPUTEXTURES) {
+    MovieClip_RuntimeGPUTexture *tex = BLI_pophead(&clip->runtime.gputextures);
+    for (int i = 0; i < TEXTARGET_COUNT; i++) {
+      /* free glsl image binding */
+      if (tex->gputexture[i]) {
+        GPU_texture_free(tex->gputexture[i]);
+        tex->gputexture[i] = NULL;
+      }
+    }
+    MEM_freeN(tex);
+  }
+}
+
 static void **gpu_gen_cube_map(uint *rect, float *frect, int rectw, int recth)
 {
   size_t block_size = frect ? sizeof(float[4]) : sizeof(uchar[4]);