vrend: pass texture levels per shader on GLES as uniform

Since GLES doesn't support QueryTextureLevels in shaders we have
to collect this info and pass it as uniform to the shader.

v2: use pipe_shader_to_prefix

Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Reviewed-by: Rohan Garg <rohan.garg@collabora.com>

src/vrend_renderer.c

@@ -418,6 +418,8 @@ struct vrend_linked_shader_program {
 
    uint32_t ssbo_used_mask[PIPE_SHADER_TYPES];
 
+   int32_t tex_levels_uniform_id[PIPE_SHADER_TYPES];
+
    struct vrend_sub_context *ref_context;
 };
 
@@ -632,6 +634,8 @@ struct vrend_sub_context {
    int num_sampler_states[PIPE_SHADER_TYPES];
 
    uint32_t sampler_views_dirty[PIPE_SHADER_TYPES];
+   int32_t texture_levels[PIPE_SHADER_TYPES][PIPE_MAX_SAMPLERS];
+   int32_t n_samplers[PIPE_SHADER_TYPES];
 
    uint32_t fb_id;
    int nr_cbufs, old_nr_cbufs;
@@ -4203,6 +4207,8 @@ static int vrend_draw_bind_samplers_shader(struct vrend_sub_context *sub_ctx,
 {
    int index = 0;
 
+   int n_samplers = 0;
+
    uint32_t dirty = sub_ctx->sampler_views_dirty[shader_type];
 
    uint32_t mask = sub_ctx->prog->samplers_used_mask[shader_type];
@@ -4245,7 +4251,12 @@ static int vrend_draw_bind_samplers_shader(struct vrend_sub_context *sub_ctx,
             glActiveTexture(GL_TEXTURE0 + next_sampler_id);
             glBindTexture(target, id);
 
-            if (sviews->old_ids[i] != id ||
+            if (vrend_state.use_gles) {
+               const unsigned levels = tview->levels ? tview->levels : tview->texture->base.last_level + 1u;
+               sub_ctx->texture_levels[shader_type][n_samplers++] = levels;
+            }
+
+            if (sub_ctx->views[shader_type].old_ids[i] != id ||
                 sub_ctx->sampler_views_dirty[shader_type] & (1 << i)) {
                vrend_apply_sampler_state(sub_ctx, texture, shader_type, i,
                                          next_sampler_id, tview);
@@ -4257,6 +4268,8 @@ static int vrend_draw_bind_samplers_shader(struct vrend_sub_context *sub_ctx,
       next_sampler_id++;
       index++;
    }
+
+   sub_ctx->n_samplers[shader_type] = n_samplers;
    sub_ctx->sampler_views_dirty[shader_type] = dirty;
 
    return next_sampler_id;
@@ -4436,8 +4449,17 @@ static void vrend_draw_bind_objects(struct vrend_sub_context *sub_ctx, bool new_
       vrend_draw_bind_const_shader(sub_ctx, shader_type, new_program);
       next_sampler_id = vrend_draw_bind_samplers_shader(sub_ctx, shader_type,
                                                         next_sampler_id);
+
       vrend_draw_bind_images_shader(sub_ctx, shader_type);
       vrend_draw_bind_ssbo_shader(sub_ctx, shader_type);
+
+      if (vrend_state.use_gles) {
+         if (sub_ctx->prog->tex_levels_uniform_id[shader_type] != -1) {
+            glUniform1iv(sub_ctx->prog->tex_levels_uniform_id[shader_type],
+                         sub_ctx->n_samplers[shader_type],
+                         sub_ctx->texture_levels[shader_type]);
+         }
+      }
    }
 
    vrend_draw_bind_abo_shader(sub_ctx);
@@ -4699,8 +4721,19 @@ int vrend_draw_vbo(struct vrend_context *ctx,
 
    vrend_use_program(sub_ctx, sub_ctx->prog->id);
 
+   if (vrend_state.use_gles) {
+      /* PIPE_SHADER and TGSI_SHADER have different ordering, so use two
+       * different prefix arrays */
+      for (unsigned i = PIPE_SHADER_VERTEX; i < PIPE_SHADER_COMPUTE; ++i) {
+         char loc_name[32];
+         snprintf(loc_name, 32, "%s_texlod[0]", pipe_shader_to_prefix(i));
+         sub_ctx->prog->tex_levels_uniform_id[i] = glGetUniformLocation(sub_ctx->prog->id, loc_name);
+      }
+   }
+
    vrend_draw_bind_objects(sub_ctx, new_program);
 
+
    if (!sub_ctx->ve) {
       vrend_printf("illegal VE setup - skipping renderering\n");
       return 0;